forman Posted February 3, 2014 Share Posted February 3, 2014 I bought this 2002 KLR engine from a listing in craigslist for $100. The previous owner stripped out the oil drain plug threads then attempted to use a tapered bolt that spread the stripped threads and cracked the engine case. I have another set of engine halves. I could transfer parts from this damaged engine into the good case halves, but I was wondering if this case could be repaired as it sits? I'm pretty sure that the case is made of cast aluminum. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted February 3, 2014 Administrators Share Posted February 3, 2014 I TIG (GTAW) weld, including steel and aluminum. This case could be repaired; however, the only way to do it right would entail disassembly. You would never get the debris from grinding and prep work out of the case any other way. If we were at Mongolia, I'd do the welding as an emergency repair. (Long Way Around example: The broken BMW frame at that remote part of the world.) Though I do understand your hesitancy about disassembling two engines just for case swapping, there's little alternative if you want a lasting repair. The good news is that once down, you can clean up the valves, light hone and re-ring, and restore the seals and gaskets. The $100 engine looks like a find. It's really a shame this kind of damage took place. A Time-Sert repair would have been a quick and permanent solution the first time around for the stripped drain threads. (Watch my video, Forman, as a professional wrench, you'll value the insight here.) Aluminum castings are very easily damaged, especially threads, which an inexperienced previous owner discovered here. I'm very excited to hear more about your motorcycling plans for the dual-sport. The KLR has a wonderful following and reputation among world travelers. A major incentive is fuel savings; the earlier, lighter models boast 50-60 mpg under lighter cruising. Later KLRs (last five model years) have gained weight, which some value for highway ride qualities, others lament for off-pavement use. Your view here? Please share more about your motorcycling interests! Moses Quote Link to comment Share on other sites More sharing options...
forman Posted February 4, 2014 Author Share Posted February 4, 2014 I knew the right answer when I posted but some how I was hoping you might say TIG would be the answer go for it! I'm excited to have you encouraging me to do the work the right way, and it gives us an opportunity to post procedures with photos. Cleaning up the valves, honing the cylinder and re-ring the piston will give me reason to ask many questions. Some that come to mind are which hone to buy? How does the removal of valve material affect the valve clearance? How do I select which rings to buy to complete the top end service? I have a long KLR story... I guess I should get it recorded so let me begin. I purchased my first motorcycle in 2012 (I'm 53 now) a 1996 Kawasaki KLR 650 with 32 k miles and several maintenance issues. I bought the KLR because a coworker owned one and he recommended the bike based on his thoughts of how I would enjoy riding. I bought a Clymer manual and began learning that most everything on this bike needed attention. My coworker friend thought I was crazy because it was all he could do to keep air in the tires and gas in the tank of his bike, why was I constantly taking mine apart?. I live in rural America and have many miles of dirt roads to ride but discovered soon that the tire tread made a huge difference on the slippery gravel I rode on (kinda scary to a new rider). I also enjoyed highway travel in fact I rode my bike to see my kids who live on the east coat a 3400 mile round trip. I made some ammo can panniers to help carry my camping equipment. Sometime before the trip I bought a 2006 KLR that had been stolen and returned to its owner in really beat up condition. I basically bought the frame and accouterments for $250 because I needed a muffler and turn signals and a skid plate also a rear shock in better condition. However the engine was also included in the deal... I brought it home thinking that I would eventually sell it as junk iron. One day I began disassembling the trashed motor ( the crank would not even turn in its bearings) I began to think that I could rebuild this engine and have 2 KLR's. I had no experience in doing this only the Clymer manual. The second photo shows the debris I dug out of the crankcase. The third photo shows the cylinder and piston. The fourth the crankshaft. The fifth is of the valve seats and broken valves. Just when I thought it impossible I realized that it all cleaned up well and with some money I could replace what was broken or bent or evaporated right??? What was I thinking!? My daughter was getting married soon and my wife and I would soon be welcoming grandkids 4 and 5 there would be no extra money to try to resurrect this motor. So I put the project on hold for about 6 months. It wasn't until the ride home from the east coast that I decided to complete the build even if I had to use salvage parts ( I know I know not a good idea). More later.... Quote Link to comment Share on other sites More sharing options...
forman Posted February 4, 2014 Author Share Posted February 4, 2014 Continuing with the stolen bike repair... I chose to replace all of the bearings in the lower cases, I then purchased a salvage crankshaft and intended to have it rebuilt but the parts were obsolete. The repair to the valve seat, broken and bent valves, guides and incidentals was above my skill level so I had the work professionally done for about $475. Project on hold again. At some point last fall I completed the lower case rebuild and felt confident of my work. As to the completion of the engine rebuild all I needed was my cylinder re-sleeved, a piston and rings then the sleeve bored to the new piston specs and all the gaskets. Did I mention that I live in the middle of nowhere? This type of motorcycle work is difficult to acquire. Sending it off would cost about $500 and shipping. I fell victim to a smooth talking craigslist seller and bought an engine that was supposed to be a 2007 with 4000 miles. In reality it was a 1998 with many many more miles. Have you ever been able to receive a refund from a craigslist seller? Me neither. I did sell the head for half of what I paid, and used the piston and cylinder to complete my rebuild. Did I think about honing and replacing the rings? Sure I did but didn't know how to go about it so I put it all together and had a running, soon to be inspected and licensed motorcycle. The bike ran great with lots of power but I noticed that there was more vibration than my older KLR and dismissed the vibration as just being different because of the difference in bikes. One day after driving the bike around 100 miles since rebuild I decided to pull an oil sample, not to have it analyzed but just so I could look at it. I swear it looked as though it were metal flake paint it had so much metal in it! I haven't torn it down yet but am curious as to what has happened to cause this I assume it is of my hand. This is why I bought the $100 dollar engine yesterday. The photo is of the 2006 KLR that was once stolen. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted February 4, 2014 Administrators Share Posted February 4, 2014 Wow, Forman, thanks for sharing the KLR stories, others will benefit from your saga, especially the "buyer beware" experience at Craigslist. That source has a dark side, and you unwittingly walked into it. Perhaps demanding close-up photos of the engine serial numbers (which also designate year model) would have been a good idea. On that note, hindsight is always 20/20. I should talk, I'm the guy who recently bought a Honda XR650R motorcycle with "less than 1000 original miles on it", allegedly in top shape. It would not start, and the previous owner and I brushed that off to "stale fuel". I bought the cycle without starting or riding it, on the sellers word and reputation, and got home to find that no amount of kicking would start the engine—after $300 worth of tuning, restoring the dual-sport conversion pieces, a new fuel petcock assembly and flushing the fuel system, also a jet replacement that was ominously long overdue and the discovery that the air filter had been leaking dirt past its edges! Fortunately, my story had a very positive ending: The previous owner made a fair monetary remedy, and I began the project that you see featured at the magazine now as a popular how-to HD video project. I've yet to ride the motorcycle that I purchase in November. Soon it will run as new after my current work. Your grenade engine was quite a project, you made a gallant effort, and your workmanship looks clean and thorough. The unwind of this rebuild warrants close attention, we'll look at the salvaged engine as you tear it down. My first question is whether you flushed out the entire lubrication system during rebuilding. This engine had aluminum grindings everywhere, and though it looks like you did a very thorough cleaning job, could aluminum debris have been left in unopened oil passageways or galleys? At this point, if all of that metal circulated for 100 miles through the engine, there's a good possibility it will not be easily flushed and has caused damage. However, a teardown is work, time and money, it's worth contemplating whether you'll find real damage or remnants of earlier chaos. Another curiosity is the bent connecting rod and how you remedied that problem. A crankshaft with flyweights and shafts out of alignment or imbalance could cause vibration and quickly chew up the engine case. Let's move the "which hone" question to the tool section, I'll detail my approach as soon as you post that tool topic. As for the valve face and seat cutting and valve stem height, if slight this can be adjusted with a valve adjustment (shim or screw adjuster method, depending upon the engine). If you're concerned about a baseline valve stem seated height, measure the seated valve stem's height above the valve guide. Use that as a reference for restoring the valve stem height—either by cutting the valve stem end (only slightly, do not create a hazard like a short stem causing a rocker to run off the stem and hit the retainer or dislodge the keepers!) or by installing new valve seats at a machine shop. Again, if the seat cutting and valve face grinding are slight enough, you can simply adjust the valves by the factory method to restore clearance. If faces take too much material to straighten up, replace the valves. Then your only concern would be seat cutting depth. Use discretion. Piston ring choice is dictated by the type of piston and the cylinder wall material. If Nikasil, use the factory recommended rings for that surface and honing angle. If you need to sleeve the cylinder (like I'm currently doing as my preference with the XR650R Honda engine at L.A. Sleeve), use the rings recommended for the honed sleeve material. L.A. Sleeve uses a patented moly-chrome alloy iron liner. I will use a cast (not forged) replacement piston with recommended rings for my usage. I opted out of a forged piston, they run more clearance, and I'm not racing. OE is a cast piston. Moses Quote Link to comment Share on other sites More sharing options...
forman Posted February 4, 2014 Author Share Posted February 4, 2014 I'll quickly address your questions. I painstakingly cleaned all passages but I could have had a piece of debris lodged in a passage restricting flow. Sorry I mentioned replacing the crankshaft but forgot to mention that the connecting rod was replaced as well... another used part. I will pull the oil filter soon and see what it has picked up. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted February 10, 2014 Administrators Share Posted February 10, 2014 Note: Forman and I continue our discussion and his tear down and inspection of this engine at: http://forums.4wdmechanix.com/topic/264-kawasaki-klr-motorcycle-engine-teardown-and-inspection/. Join us there, the goal is a reliable and roadworthy 2006 Kawasaki KLR 650 dual-sport motorcycle! Moses Quote Link to comment Share on other sites More sharing options...
forman Posted February 26, 2014 Author Share Posted February 26, 2014 I removed the left crankcase half from my craigslist purchased 2002 KLR engine with 14000 miles. On the tear down I discovered that the engine looked very good despite its age. I wanted to include this type of repair because I think it is very possible to find yourself in this position... well maybe not quite this bad. The previous owner informed me that he had stripped the threads when changing oil. He was not aware of the time sert repair and attempted to use a "wedge" type of bolt to seal the oil in the crankcase. I guess it still leaked and he elected to use epoxy... that didn't work either so he bought a replacement engine. When we met he was selling his bike with an extra engine for $100 I inquired about the extra engine and bought it knowing that I had another crankcase. So why repair instead of using the other crankcase? Using this crankcase will keep the original engine together. There is a bearing race in the left crankcase that looks to me almost impossible to remove. If I can't repair and have to use one of my higher mileage crankcases the bearing and race union would be questionable, What if it wasn't even made by the same manufacturer? I will just post these photos and see if the viewers think it is repairable. Quote Link to comment Share on other sites More sharing options...
forman Posted February 26, 2014 Author Share Posted February 26, 2014 I've included a photo of the bearing race, I would need to press it out from this side I don't know if you can tell or not but the edge of the race is beveled. Also a couple of photos of a non damaged oil drain hole and threads Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted February 27, 2014 Administrators Share Posted February 27, 2014 Forman, I TIG weld, and as they say, there's no project that is "impossible", it's more like a matter of cost. The biggest issue with a repair in that area of the case is warping of the case. This case half should be bolted down solidly before welding (TIG or "heli-arc" method). Welds must penetrate well into the aluminum to provide an oil seal and reduce risk of porosity...The thread hole could be "plug welded" (filled completely with weld beads) using the same aluminum TIG method, then drilled and re-tapped, with the plug's new seat machined flat. Machining or, minimally, light surfacing of the case after welding would be advised, this case must mate smoothly along the sealing edge. This would be an extreme repair but feasible if there were no alternative. Take the case to a shop that specializes in aluminum repairs and machining. Get an estimate and compare with the cost of finding another case half in better shape. The machining on these Japanese cases is usually spot on, meaning you could get a used case half from a donor engine and have it fit properly. Frankly, this is likely the cost-effective solution. As for the plain bearing, I would find a new bearing before pressing this one out. It looks proprietary, possibly unique to this application. (There may be a concealed bearing number on the outer shell that could be checked for a cross-reference.) It might be easier to source the bearing through Kawasaki. Others may have thoughts and suggestions...This is my two-cents. Let us know what you wind up doing, Forman... Moses Quote Link to comment Share on other sites More sharing options...
forman Posted February 28, 2014 Author Share Posted February 28, 2014 I spent some time this week asking questions about this type of repair and I've concluded that finding the right TIG welder with the right attitude and knowledge toward repairing my cracked case is going to be a daunting task. Also this repair for me is cost prohibitive. I'm going to use one of my other left side cases that I replaced all of the bearings and seals in previously, with the exception of the bearing race I spoke of earlier. The replacement case race is of the same manufacturer and a test fit up was made. I feel good about my decision. The rebuild will be entitled Kawasaki KLR 650 engine rebuild. Thanks for all of your help on this one Moses! Quote Link to comment Share on other sites More sharing options...
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