Moses Ludel

Adam F...Pressure is either bleeding off or you simply do not have sufficient fuel supply to the TBI unit. My test at this point would be a "T" on your pressure gauge kit with a fuel hose or pipe running to a safe fuel container. Turn on the key (without cranking or starting the engine) and note the fuel flow into the container when the pump is running. This indicates fuel flow volume, not just pressure, and you need both. Note: For the engine to idle, you need a shut-off valve on the drain port of the "T" to adjust enough fuel pressure and volume for the engine to idle. Unrestricted flow at the drain hose or pipe could create too much of a pressure drop, in which case the TBI unit would starve for fuel. For measuring the fuel flow while cycling the fuel pump without the engine running, you want a drain hose or pipe with the same I.D. as the supply line from the tank to the TBI unit. The shut-off valve at the "T" is a safety backup during your tests and also serves as a means for restricting and regulating the bleed-off rate as necessary. You may need someone to cycle the key-on and trigger the cranking mode while you watch the fuel flow and pressure. Sounds awkward to keep jumping out of the Jeep to see what's going on. Be careful with the gasoline flow into the safe container, gasoline is highly flammable and must be kept away from heat and sparks! One diagnostic tool that works surprisingly well with TBI units is a simple timing light hooked up to #1 cylinder's spark lead. Since your engine will idle (thankfully!), you can check the fuel flow spray pattern readily. Timing light hooked up, aim the light at the discharge nozzle of the injector with the engine idling. You should see a uniform fuel spray cone pattern if the fuel flow is adequate and unrestricted. Since idle seems okay and tip-in under load becomes an issue, try accelerating the engine at a steady rpm increase that might bring about the stumble. Watch the fuel spray pattern as this happens, and notice whether the spray diminishes simultaneously with a pressure drop on your fuel pressure gauge. This can pinpoint a lack of fuel flow in relationship to fuel pressure. I'm hinting that the fuel flow may be restricted or erratic as Stinger87 encountered with the fuel filter and tank sock issue. The in-tank pump's pressure, the fuel flow volume (involving the tank sock, fuel filter, a pinched or restricted supply line and similar concerns), pressure into the TBI regulator and the regulated pressure, plus the actual injector flow, are each important. You're right about the O2 sensor playing a part in all of this, with the typical trouble symptom being an engine operating in limp mode. A "bad" or contaminated O2 sensor can wreak havoc. An EGR issue (valve plunger not seating, an EGR valve stuck open or closed, etc.) can also cause this kind of erratic engine behavior. I heartily recommend not "borrowing trouble". Simplify by going back to the original malfunction symptom and focus on its possible causes. Needless parts replacement and experimentation often solve little, this can be costly, and it leaves the solution to chance. Let us know how this troubleshooting unfolds... Moses

Agreed on the performance level, RareCJ8! I freshened up the 1950 CJ-3A's L-134, new rings, pistons and a valve grind. It was still a "drone" on-highway. Off-road was a whole other thing in low range. I did prefer the folks' 1964 CJ-5 Jeep with factory T98A four-speed option and the F-134. Though not a world beater engine, it did boast 72 horsepower, and the 12-volt electrics helped. JohnF's 1967 Jeep CJ-5 with the Dauntless (Buick 225) V-6 represents a milestone breakthrough. My '55 Jeep CJ-5 project for the Jeep CJ Rebuilder's Manual: 1946-71 had a retrofit truck four-speed, the F-134 and a vintage Warn overdrive. 5.38:1 gearing is a plus. Your GPW was 4.88:1. Big difference off-pavement. A compound low truck box means a double reduction over the T84 or a T90. We could knock the primitive steering, closed knuckle front axles, side-drive Spicer 18 transfer cases and many other anachronistic features on these vintage Jeep 4x4 vehicles; however, many stockers or restored models still ply the trails at Moab and the Sierra Range. Your GPW, my CJ-3A or a vintage CJ-5 were the quintessential hunting, mining, ranching and overall backcountry rigs of their day. They earned that distinction! Thanks for sharing... Moses

Diamond Jr...Helpful information...Some quick questions: 1) Do the wear point marks on the transmission's front bearing retainer appear further back than the release bearing collar's rearmost position? 2) Have you checked the "stack" depth of the release bearing when fully retracted? On the #2 question, there is a specific distance from the release bearing's face (when retracted fully toward the transmission) and the rear of the engine block. When we set up a flywheel, clutch disk and release bearing system, the release bearing must always retract enough to move free of the clutch disk fingers when the clutch is fully engaged. This is figured with the flywheel, clutch disk and clutch cover attached correctly to the crankshaft. In your case, I gather that the clutch disk and cover are in place. If the cover is bolted securely to the flywheel and clamping the disk, the cover's release fingers stick out a specific distance. I'd like you to measure the distance from the block's machined surface (where the bellhousing attaches) to the stick-out point of the clutch cover's fingers. You can do this with a straight edge held across the fingers from 3 to 9 o'clock and parallel to the block's machined face. Measure this distance and confirm at each side with the straight edge held parallel to the block. Once you know this "stack height" from the bellhousing attachment point to the cover fingers, you can move to the bellhousing and transmission. With the transmission bolted to the bellhousing, install the release arm and release bearing. Slide the release bearing collar to the normal, full-release position on the front bearing retainer sleeve/tube. Place a straight edge across the bellhousing's machined front face at the 3 to 9 o'clock position. Measure to the forward face of the release bearing. In this fully retracted position, the release bearing's face must be deeper in the bellhousing than your earlier measurement of the clutch cover fingers to the block's machined surface. This is the best way to assure that the release bearing can retract sufficiently to clear the fingers of the clutch cover when the clutch pedal is fully released (clutch engaged). Try this approach to make certain the release bearing will function properly. Your findings should be consistent with the #1 question. The bearing collar should be at or deeper than the indicated wear point on your used front bearing retainer. If so, this is as far as the release bearing collar needs to retract. Let us know what you find... Moses

Glad you worked this out, JohnF. If you can find a home for the 2A/3A springs, freshly rebuilt, that would be great. Do we need a classified section at these forums for moving members' equipment and parts like these springs? Moses

These were great vehicles, on par with the Grand Wagoneer yet a bit slimmer and utility bent. A versatile wheelbase, the 2-door models have a large following. Using AMC's 258 inline six or the range of 304/360 and even 401 V-8s, these vehicles present a nice balance with strong components. Full-time and part-time 4x4 systems and several other differences distinguish these models. Note the axle types, transfer case, engine and option package. I'd like to know the year and equipment. This could be a real find. I've considered a project around the FSJ Cherokee 2-door for many years. (A briefly available 4-door has less popularity, I'd opt for a Grand Wagoneer over that model.) Swapping a Cummins 5.9L ISB 24-valve engine with the right transmission and Dana 60 or AAM 9.25"/11.5" axles would be a possible approach. 33"-35" tires and a heavy spring chassis lift would accompany that swap...My imagination runs wide around the FSJ Cherokee—even a stock restoration would be exciting! Moses

RareCJ8...Uncomplicated, "low tech", easy to repair, utility and off-road 4x4 capability...I restored a 1950 Jeep CJ-3A in 1969-70...Great times were had with these vehicles! Moses

Welcome to the forums, Diamond Jr...Could you please add a couple of photos to illustrate your "problem"? I'd like to see the release bearing in the extended and retracted positions that you describe. "90%" onto the retainer would be unacceptable if you mean that the bearing does not fully slide onto the sleeve/tube. I'm assuming that you're using the release arm, slave cylinder and master cylinder that work with a '95 bellhousing? The four-cylinder engines do not use the shim/plate between the block and bellhousing, but you do use a dust cover at the lower section of the bellhousing. You can post the photos here at this topic, and I'd be pleased to comment on what you're encountering. Thanks! Moses

JohnF...Could very much be stock springs for 1970. The "turn down" is to eliminate spring leaf friction. More modern springs use nylon inserts at the ends to accomplish this. The aim is to prevent premature damage to the leafs from rusty, dirty spring ends digging into the adjacent leaf. You've seen that pattern in worn old springs. As you discovered with the loosening of the plates for spring bolt replacement, the natural curvature of the spring leaf creates abrasive angles at each leaf end. This presses into the adjacent leaf when the springs stretch out and the leaf ends curve inward. As many of us have discovered, Jeep was poor at illustrating parts in both the factory parts manuals and the service manuals. Jeep was also inconsistent about parts sourcing and model year changes for parts. Parts often got carried over from previous models and actually do not "match" the year of the vehicle. Clear changes take place between major model shifts, like the 2A/3A/3B (MB/M38) to CJ-5 (M38A1), or the Kaiser era changeover to distinct AMC/Jeep models in 1972. If these springs have the correct length and width, are not broken leafs or beyond rebuilding, and if the price is right, there is nothing "wrong" with leaf springs that will not chafe between the plates. The curved ends, in themselves, do not present a problem if these springs are the correct length, width and spring rate. Moses

Interesting...Is this a splined coupler or a slip yoke? If a splined coupler, even if you did not separate the spline section, you might have an issue with spreading or thinning the OE grease by extending the coupler and returning it to the normal/operating position. Please clarify whether this is a splined coupler or slip yoke. If migrating grease was an issue, it sounds like a slip yoke... On aftermarket shafts with splined couplers, a special "coating" on the splines often acts as a friction barrier. This is typically blue in color, and you've seen it on custom drivelines with splined couplers. As for slip yokes, a spline matchup with the original position is seldom considered, and unless you carefully mark the slip yoke and transfer case output splines, there's very little likelihood that the shaft will end up at the original spline alignment. Repositioning the slip yoke on the transfer case output splines would seldom create an issue unless there is abnormal spline wear on either the coupler or the output. Of course, with a splined slip coupler, you must have the driveline's U-joints aligned or "in phase". When a splined slip coupler is taken apart and reassembled, the U-joint and flange position at each end of the driveline must match and be in alignment. Additionally, with a balanced driveline, these matched positions must also be consistent with the position of each U-joint flange when the shaft was built and balanced. Moses

Are your original springs beyond rebuilding? They are 39-5/8" length, right? Could the shop rebuild it for the same cost as the CJ-2A/3A springs? Moses

Welcome to the forums, nbruno! I am at Moab EJS (not at my shop/studio) and would like to explore the Davies Craig water pump further. I took a quick look at the corporate site, and the electric water pump is interesting. I would like to research the longevity (duty cycle) of the electric motor when running continuously or thermally activated. It would run continuously in a warmed-up engine in all likelihood, and engine coolant heat is substantial. Also, re-routing the belt to stop turning a squeaky mechanical pump is suspect. The parked impeller could create a blockage of flow. I would like to know the problem with the OEM water pump. Is anyone making an OE mechanical water pump that does not create trouble? On that note, is the problem squeaks or actual bearing and eventual seal failure? Squeaking can sometimes be strictly belt and pulley related. Please share what you know. I'm glad to research further so we can determine a sensible remedy... Moses

The 2A and 3A have an 80-inch wheelbase, the M38A1 and CJ-5 introduced the 81-inch wheelbase. This is a clue. Were your original springs broken? Why were they not the ones you had rebuilt? Trust you will find a buyer for these flat-fender era springs. Advertise them and include the main leaf length (typically eye center to center) to be sure the springs will fit before shipping them to the buyer...The price is right, you had the springs rebuilt by a reputable shop. Add freight to your cost for the 2A/3A springs plus rebuilding charges, and you'll have your investment back, JohnF! Moses

I'm trying to imagine an engineering need here. The available transmissions did not require this drop. Did the bellhousing require a drop to clear the firewall? Does the V-6 225 engine set lower than the centerline of an F-head four-cylinder? How is this related to the Buick V-6 option? Exhaust clearance for the V-6? Something that requires lowering the back of the engine? The distributor is conveniently at the front. Dropping the rear (engine/transmission) cross member may explain the rear axle wedges, too, although dropping the transfer case should decrease the U-joint angle at the front of the rear driveline. That would require tilting the rear axle pinion upward to achieve a complementary (cancelling) U-joint angle to match the rear driveshaft's front U-joint. Which way did the wedges originally face? Moses

You know the history of the Jeep, JohnF, so presumably these are OEM origin. The reason these are used is to rotate the axle and adjust the pinion shaft/U-joint yoke for proper U-joint angles at the rear driveline. On your vintage V-6 Jeep CJ-5, the wheelbase is only 81". The rear driveshaft is short and susceptible to vibration and damage if U-joint angles are not "spot on" and cancelling each other at the rear driveline. I had a lengthy discussion with Megatron about U-joint angles, and you'll find it helpful for understanding the use of these wedges. Jeep was trying to match the angles at each end of the rear driveshaft, which is correct for a shaft with a single-Cardan (cross) joint at each end of the driveshaft: http://forums.4wdmechanix.com/topic/108-dodge-ram-3500-with-48re-automatic-transmission-shudders-on-take-off/ My response at the later posts provides details...For the rear driveshaft, you're striving for matching U-joint angles with the vehicle at ground/curb static height and normally loaded. The single Cardan joint angles should cancel each other in that mode. The wedges are used for changing the U-joint angle at the rear axle to match the transfer case joint angle. Moses

Yeah on the AX15 rebuild, great job, TTippetts! Understand the Jeep J10 dynamic and why the TBI 350 V-8. Though less horsepower than an LS, these engines produce excellent torque, which you probably want anyway...Many GM Suburban 4x4s with the 350 TBI lugged larger travel trailers with the right axle gearing. We had an '87 K2500 (cargo doors and 4WD, Federal emissions) and really valued that rig and its THM400 behind the TBI 350 V-8. Last heard, the truck has clocked over 300K miles on the Mr. Goodwrench crate engine installed before we bought the Suburban at 140K miles. Original owner had used Mobil 1. I kept the engine on Mobil 1, and it's still running on Mobil 1 for the friend that bought the truck at 180K miles! Please keep us posted on the J10 project and developments, that section at the forums could use your input and findings! Moses

Interesting video and comments...The added foam "jetting" change seems two-fold, first a "choking" of air flow through the restriction, and secondly, according to the YouTube presenter, a possible offset of what he calls "reversion" air flow. The first factor is much like the claims of aftermarket air filter companies that boast "less restriction", only in this case it's the opposite. I've changed back to a stock air filter and even added the missing OE anti-backfire screen, an additional air restrictor if you will, to the Honda XR650R motorcycle. While "uncorking" these Big Red Pig models involves removal of the stock air box restrictors (done by the PO, none in place), actual filter air volume is a measurement of CFM flow and the filter's surface area. I'm banking on Honda having enough sense to provide adequate air volume through the stock filter and the vital OE anti-backfire screen. (Many remove the screen for more flow. Envision the bike on its side with fuel flooding out into the air box. This is a major fire hazard with the anti-backfire restrictor removed!) I only re-jetted to what is actually stock on all non-U.S. market Honda XR650R cycles with this same carburetor, compression ratio, etc. This was the conservative approach, and the HotCams Stage 1 camshaft should be okay with that jetting, too. Stock jetting for the non-U.S. market is 175, I went for 172 at our altitude and mountainous, high desert riding environments. I'll see whether the stock air filter creates any kind of enrichment factor. Note: RPM plays a role in the main jetting needs. I'm not "racing" this motorcycle nor redlining the rpm constantly. In fact, I need to conserve fuel at my remote riding venues and make sure this engine stays intact and reliable. What I'm hinting about is that filter surface area (or a foam restrictor like this video describes) would simply control air flow volume. So does the choke or a dirty air filter for that matter. The engine's air requirements are based strictly on CFM requirements for the cylinder displacement, camshaft valve opening duration and lift, and the valve timing "events" as the video mentions. The OE carburetor, at least theoretically, should have the right CFM flow for the engine. My XR650R uses a 40mm Keihin, no CFM rating to share here. CFM flow of a carburetor is based on the engine speed as well. Jack Clifford, an inline six devotee, and I discussed Jeep 4.2L six-cylinder requirements years ago, and he threw out a carburetor formula: 1 CFM for each cubic inch of displacement to run the engine at 4,000 rpm. More rpm, more CFM flow required. Many sport bike motorcycle engines are barely on the throttle at 4,000 rpm. So, assuming the engine has the right carburetor, and an unrestricted air filter of the correct surface area to match the CFM needs for the carburetor and engine, there's still another factor: the air box flow. This is a science, and latent horsepower is often found in a redesign of the air box, affecting the air flow and velocity to the carburetor or throttle body intake. The filter, in combination with air box flow dynamics and air delivery changes, can dramatically impact performance. There is an entire automotive aftermarket devoted to these performance improvements. OE air boxes are often misshaped to meet fit and engine bay requirements, and so forth, restricting the performance of the engine. The presenter mentions "reversion flow", and as he describes it, that would be a function of camshaft design/lobe profiles, valve timing and engine speed, manifold vacuum and the induction system design. He may be right on with the reversion taking place, and that could be a factor of air box placement limitations or even air box tuning to deliver a certain kind of performance at a given engine rpm. This tuning could be performance and/or marketing driven. The "foam jetting" is a restriction of air flow volume at the filter. If the engine is getting enough air (CFM flow) with or without the restrictor foam, jetting should not be impacted. Although the blockage alters the engine's ability to access air, that does not necessarily mean the engine is not getting enough air. Choking the engine with the choke valve is entirely different: The choke valve restricts the incoming air and also raises the vacuum/fuel draw from the carburetor idle and pilot circuits (enriching the mix further)—while at the same time restricting incoming air (CFM) volume. Not sure whether the bike in the video is carbureted, but I'm assuming that's possible by the mention of "jetting". If the cycle had EFI with an oxygen sensor regulating the A/F ratio, regardless of intake air flow restrictions, the A/F ratio issue would be moot. A Jeep engine with MPI will adjust A/F even for a dirty air filter. A/F must remain constant to meet emission requirements, and the engine and vehicle simply will not perform well with the lessened air volume: Injector fuel flow gets lowered to match the available air. That's the beauty of EFI/MPI versus a carburetor, the EFI adjusts for altitude changes, available fuel and air, manifold vacuum and barometric pressure. By contrast, the alteration of air intake flow, air velocity or air volume into a motorcycle engine with a carburetor can have a distinct effect on jetting. The video implies that the air box in question actually flows more air than useful. If the engine runs better and does not show signs of excessive enrichment (blubbering, fouled plugs, blackened exhaust soot and such), then it's getting improved flow or simply running richer and obviously better than stock. Forman, keep in mind that later EPA requirements for on- and even off-road vehicles, including motorcycles, demand the leanest A/F mixes tolerable. Restricting the air box intake with foam, as illustrated in the video, might be just enough to enrich the mix slightly while still allowing enough CFM flow to meet the engine's requirements. This could be the source of happiness for the engine...You'd have to do a four-gas exhaust analysis, with the motorcycle on a dynamometer under various loads, to see what's really going on here. Moses

JohnF, the spring centering bolt heads must reach through the wedge spacer and catch the axle spring perch hole. This is how the rear axle stays in alignment. It also helps hold the wedge in position. Especially with the wedges, any movement or shifting of the axle housing/perches will allow the U-bolt nuts to loosen. The wedge(s) will be loose, and the axle can shift out of alignment. Dangerous looseness of the spring U-bolts and hardware will result. You can find spring centering bolts with deep heads, the length you need. To save time, you can also very carefully double clamp (large clamps!) the spring leafs together near the center bolt before changing out the spring center bolt. An option would be a large vise as a holding fixture, perhaps with a set of C-clamps as a safety backup. Do not let the leafs loosen, this could misalign the center bolt hole. You would struggle to get leafs back in alignment. The shop that rebuilt the springs has access to center bolts like I describe. These are essentially the same bolts you have now only with taller heads of the correct diameter and height for the wedge and perch holes. Moses

Congrats, Forman! Great work and thanks for the compliments on the Jeep CJ Rebuilder's Manual: 1972-86. The book will be very helpful with any of your other endeavors around this CJ-7. I'm finding HD video increasingly more effective as an instructional tool. Want to add "time-marking" and indexing so folks can jump back and forth to specific points within a how-to video—like we do with a print book. I've set up the shop/studio for detailed tech in high definition video. You'll see the first clearly HD product in the Honda XR650R top engine assembly video I'm now editing... Moses

Thanks for the comments about the L.A. Sleeve work and video. The upper engine assembly video will be available shortly. Forged pistons are generally higher compression ratio. The material is intended for severe duty pounding, typically in a racing environment. The expansion rate for forged alloy pistons is such that the piston-to-cylinder wall clearance must be wider, and these pistons can be noisy at cold start and require warming up the engine to quiet the pistons down. Newer design forged pistons, in some applications, are less noisy. Cost for forged pistons can be high. Cast pistons are generally OEM replacement. On automotive applications, I most often use Silv-O-Lite (United Engine) hypereutectic pistons, which are technically "cast" but offer much better service and longevity. This is a good choice when forged pistons are overkill for the application, compression ratio and intended vehicle use. For the Honda XR650R, I consulted with L.A. Sleeve about the quality of the L.A. Piston Company replacement piston. It is essentially an OE replacement piston, LAPC's "Pro-Cast" design, built to close tolerances to last at least as long as the OE piston, which holds up quite well with normal use. Add to this the precision machine shop honing and a quality ring set, also provided by L.A. Sleeve, and I am certain the setup will last a very long time. If I thought a forged piston would last longer in my intended use of the motorcycle, I would have opted for a forged Wiseco or similar quality piston and matched rings. One concern that pops up in any case is engine operating temperature. A forged piston could tolerate extreme heat, and since I did stick with the OE equivalent cast piston, my focus will be improving the engine's cooling ability. Before getting overly concerned about the piston material, I am reminded that my earlier air-cooled Honda XRs (an XR350R and the XR500R) each use a cast piston and have survived Nevada desert riding year 'round for decades. The Honda XR650R motorcycle engine has 10:1 compression (stock) and liquid cooling. It will hold up very nicely with a cast piston. Moses

Smart move with the "decorative" rivets! That should work. Welding the cross member into place makes sense when done properly...Hot riveting is difficult to do in this day and age, the equipment is long gone. I wonder whether you could do a hot rivet with a carbon arc welder. Thanks for sharing and keeping us posted, the reworked springs look great! Moses

Congratulations, TTippetts! Great job there...The J10 sounds intriguing, likely you passed on an AMC 401 or 360 V-8 buildup for cost reasons. The AMC engines have become very spendy to rebuild! The small-block 350 Chevy V-8 has been a logical mainstay, and a TH350 should work well, too. Did you consider a later LS engine? Cost should be coming down on recycled GM truck engines. Keep us posted. Pleased that your AX15 is back together and performing as new! Moses

Read my reply at the General Repairs and Technical Tips topic: http://forums.4wdmechanix.com/topic/295-how-to-hone-an-engine-cylinder/. Also, take some "Forman" photos and accurate measurements of the cylinder you plan to hone. Share these details at the "How to Hone an Engine Cylinder" topic. I'll provide further tips based on your findings and photos. You can do this, Forman! Moses

First, it's all about piston to wall clearance and ring end gap measurement. These must stay within the manufacturers' guidelines for acceptable limits. Years ago, in automotive circles, rings were commonly available for in-chassis engine overhauls or "ring and valve jobs". Perfect Circle, I recall well, had piston rings to fit 0.000"-0.010", designed for the OE standard size pistons. Filing ring end gaps to size was common practice if a bore was only slightly oversize and the new ring end gaps were too close. This approach worked okay for "in the day" engines to 8:1 compression ratio that ran with 160-180 degree F thermostats. When ring gaps are too narrow, there is no room for normal gap changes at different cylinder wall and piston temperatures. Gaps too narrow, and the rings can actually seize in the cylinder. My tools include two hand-operated ring gap filing fixtures, and I've used modern power files on custom ring sets (packaged without sizing) for high performance engines. Typically, new replacement ring sets for popular bore sizes or oversizes are accurately gapped from the factory. Filing rings is a rare need today. If you buy standard or oversized rings to match the piston size, the ring gaps should be correct if the bore diameter is accurately on measure. When in doubt, measure the ring gaps with each ring or spacer level in the bore. The issue today is that manufacturers and consumers have shifted to "remanufacturing" of exchange engines or a rebuild at the local machine shop. In the process, an engine block is always bored and finish honed, and the standard U.S. automotive oversizes are 0.010", 0.020" and 0.030", sometimes to 0.040". (Similarly, metric oversizes typically run .25mm, .50mm, .75mm and 1.00mm.) This has become so common that the "reman" shops like to bore every first-time go around U.S. block to 0.030" if possible. Tooling can be readily adjusted and pistons for this bore size cost less at the wholesale level. Today, the other oversizes are often special order. Caution: 0.060" or larger bore sizing is considered a high performance approach for blocks that do not have core shift or thin walls. I recommend ultrasonic testing of cylinders before considering 0.060" oversize on a Jeep 4.0L inline six block. Ford "351M/400" V-8 blocks are notorious for core shift and should be ultrasonic tested for boring even to 0.040" oversize. For motorcycle and automotive engines, slight honing should stay within end gap norms for the new piston rings. The piston to wall clearance measurement should also indicate whether or not you've exceeded the ring gap limit. If you have too much clearance, you'll need to bore the cylinder(s) for the next oversize piston and ring size. Typically, the two measurements coincide, so if you use the OE piston as a measurement baseline and come up with acceptable piston-to-wall clearance after honing, the new rings for that bore size should also have acceptable ring gap measurements. Footnote: Forman...Hone and do the piston measurement before ordering new rings or a new replacement piston for your Kawasaki KLR thumper motorcycle engine. What size rings are available for the KLR650 engine? Honing should not remove much material. If the cylinder has too much taper, it's wise to re-bore and machine hone for the next size piston and rings. If there is noticeable taper, the traditional approach is to carefully cut the area above the taper with a ridge reamer and remove the ledge. That cut ridge diameter, once honed with the rest of the bore, becomes an appropriate point for measuring the piston-to-wall clearance. Note: If the engine block or cylinder can be honed after cutting the ridge, a stone hone would be mandatory for truing and uniformly sizing the bore of the cylinder...If there is significant cylinder taper and a noticeable ridge, the added cost of machine shop boring and fitting of an oversized piston(s) and rings would be advisable. I refer to "cylinder(s)" because our members and guests range from single cylinder motorcyclists to V-8 and V-10 automotive/truck owners. If you need to resize any one cylinder in a multi-cylinder engine, you must resize all cylinders to the same oversize. Matched new pistons and rings in that new size would be mandatory. Minor honing with a drill motor is typically limited to engines with very light cylinder wear and the need for seating and sealing a new set of rings. For motorcycle engines, especially two-strokes, it is not uncommon to have a bore size still within tolerance, both before and after honing, with the installation of a new piston, pin, circlips and rings. This is especially true with Nikasil plating. After cleaning, if a Nikasil bore looks unblemished and still shows a strong cross-hatch pattern, leave it alone. If there is a need for honing a Nikasil cylinder, I strongly advise having L.A. Sleeve Company or a similarly qualified machine shop perform that work. Moses

Craig, thanks for the compliments! The links I provided cover a lot of ground with the troubleshooting and understanding the functions and identities of the various Jeep 2.5L TBI components. Our forum exchange was a hands-on like yours, and some wading through the materials should provide insights. Of course, I'm pleased to go further if you exhaust the details offered and haven't solved the problem! You mention the wiring harness splicing and butt connections, and that is a concern. For EFI sensors, the important signals for the ECU are dependent upon wires with integrity and the correct resistance. Butt crimp connectors are terrible when resistance is critical: There is no assurance that all strands of the wires will make contact. There's also the risk of moisture wicking into the connector and up the wire insulation, a problem that worsens with humid climates, 4x4 water fording and even the occasional clean up at the car wash! Crimp connectors work for trailer light wiring and other tasks where resistance loads are not critical—just step up wire gauge and use the right fuses! Also, you described the sensors looking like mud and acid. Shorts to ground or voltage leaks to ground can result. Like a dirty battery case, if the sensors are encrusted with conductive material, and that can include soil with minerals, there could be voltage leaks to ground. The terminal of a sensor could be shorting mildly to the brass or metal shell of the device and creating resistance or voltage changes. Even minute voltage changes can throw off a sensor signal to the ECU. If you cannot find harnesses or a harness change-out appears daunting, you can repair wiring properly and get good results. I like to use rosin core solder and seal the solder joints with multiple layers of heat shrink tubing. First, I place fresh heat shrink tubing, cut to the right lengths, well up the cut wires and away from the soldering heat. Take the stripped, opposing wire ends and interlace the bare wire strands together—facing toward each other. Minimize the diameter of the bare wire joint; mimic the diameter of the insulation if possible. Now you can solder the braided strands together, using rosin core (not acid core) solder. Add rosin paste as desired to assure solder flow through the bare wire strands. A finished solder joint around 5/8" in width works well, using a smaller soldering iron or a soldering gun. After the solder joint cools, slide the heat shrink tubing over the bare soldered joint and insulate the section. Shrink the tubing carefully to the wire insulation without melting the insulation. The tighter the tubing against the insulation, the better seal. You can double up with a couple of heat shrink layers...Done correctly, heat shrink can prevent shorts and moisture wicking. Note: To shrink tubing, I use a heat shrink gun, heat gun or even wooden kitchen matches with the flame passed quickly around the tubing without melting the wire insulation or burning a hole through the tubing. Practice on an old scrap of wire. Soldering takes time but can save wiring and make permanent repairs. Unless the current damage is extreme, avoid replacing harnesses. I like your approach: Restore known wiring issues first. Later, the troubleshooting will be accurate and reliable—like you want your Jeep Wrangler to be! Keep us posted and share interesting developments. Troubleshooting will be straightforward once the wiring is in good shape. Moses

Great post, Rocket Doctor!...My only trip to Alaska so far was in 1975. I was working at construction in Carson City, Nevada, and given a moment's notice offer to make the drive. My good friend, Bob "Bearclaws" Stuttsman, was the impetus for that trip. (I shared details about Bearclaws at the forum: http://forums.4wdmechanix.com/topic/149-outdoor-friends-family-and-mentors/?p=485.) Bob was as colorful as the trip itself! We drove from Carson City straight up U.S. 395 to Colville, Washington and crossed the border at the base of the Okanagan Valley. Bob couldn't stop talking about U.S. gun laws as he "allowed" Canadian Customs to secure a customs string and seal around the metal tackle box that housed his two .44 Ruger single action pistols. Canadian Customs could easily have told us to make a U-turn with the '66 I-H Travelall 4WD and our small travel trailer in tow. Instead, the tolerant official simply said, "We understand your gun laws, but this is Canada...This seal must be in place when you exit Canada at the Alaska Frontier...Here's the accompanying paperwork, Mr. Stuttsman." In those years, you could transport pistols in a customs sealed container. We each had long rifles that were declared at Customs, and there was no concern about hunting rifles. Bob had his Model '86 Winchester 45-90, I toted my 1908 vintage Winchester nickel-steel octagon barrel .30 caliber, each were traditional lever action rifles. The Fraser River, Fort St. John, Ft. Nelson and Whitehorse were each memorable. Along the Alaska Highway, a stop at the Liard River Provincial Park is a must. (Here's a quick Wiki overview: http://en.wikipedia.org/wiki/Liard_River_Hot_Springs_Provincial_Park.) After days of dirt travel (1100 miles were still dirt in 1975, this is Milepost 497), the public hot springs make a welcome break. Moose, wolves and bears are plentiful in that area. I took photos on that trip. In our living room are framed prints of photos taken alongside the Liard River at sunset and near Tok Junction, our entry point into Alaska. The prints have weathered nearly forty years of shuffling from home moves. The camera was my bulky Mamiya-Sekor C330 twin reflex 2-1/4" square format. Rocket Doctor, you'd enjoy the photo of a moose cow in a marsh near Tok Junction. Bob and I headed through the Matanuska Valley and past Fort Richardson en route to Anchorage and the Kenai Peninsula. Bob's Cousin Ned lived at Soldatna, he had homesteaded there with his brother in 1959. A failed potato crop drove Ned into a job with the local school district. We spent time on the Kenai and drove out to the spit at Homer, where I took photos of the King crab catch at the local docks. My trip back to Carson City and an apprenticeship with Local 3 of the Operating Engineers began with a puddle jumper air flight over the Cook Inlet to Anchorage...I flew from Anchorage through Seattle to Reno with reflections of Alaska the entire way. Bob stayed on at Ned's place for a bit, scouting out the Kenai as a possible move from Nevada. Our trip was the first two weeks in September, the same time you were there, Rocket Doctor! Mosquitoes were not totally obnoxious, and it was a remarkably colorful season... I would enjoy another Alaska trip. This time, I'd make a right turn at Tok Junction and head for Denali and Fairbanks. Maybe on a dual-sport motorcycle, though I'd avoid overnight tent camping in bear country! It's one thing to sleep in a tin trailer with two rifles close at hand, another to sleep just a nylon tent wall from a grizzly! Moses