ahamza Posted September 20, 2005 What would cause these to leak? I had the cases apart 6 months ago on my '03 and replaced them at that time. I replaced all the seals. However, oil is migrating from my transmission bath to my engine oil bath. I am hoping that one/both was just a bad seal Thoughts? Share this post Link to post Share on other sites
ShadyatBest Posted September 20, 2005 a crank that is a lil sideways will do that. It will wobble. I had that problem after i changed the crank bearing on my cr250. The seal on the tranny side kept leaking and causing my bike to run rich and foul the plug in hours Share this post Link to post Share on other sites
Scott Chapman Posted September 23, 2005 I'm having a similar problem with my bike, although it is a CRF250. oil is migrating from the transmission to the engine. We rreplaced the counter balance shaft seal and it is still doing it. I don;t think it is the crank shaft seal as the bike runs well. Where else could the oil move through to the engine?? Share this post Link to post Share on other sites
kelstr Posted September 23, 2005 I'm having a similar problem with my bike, although it is a CRF250. oil is migrating from the transmission to the engine. We rreplaced the counter balance shaft seal and it is still doing it. I don;t think it is the crank shaft seal as the bike runs well. Where else could the oil move through to the engine?? i was the first idiot to find this problem on the 02 . all crf's will do this, the rt crank seal and the balancer seal are the only places it comes in at, the problem is that the seals don't fit very tight in the cases, you need to peen and locktight the seals into place to keep them from being sucked or popped out ! its a very simple deal , you don't split the cases, if you do a search i have explained it in detail and i have a parts list with numbers Share this post Link to post Share on other sites
motoclay Posted September 23, 2005 My 03 has done that a couple different times. It was teh crank seal both times. Its a double lip seal, and the lip that seals the tranny from the engine is super super tiny. U have to be real careful when u put it back together or it will happen again. Put a little oil on the seal and the crank gear when u go to put it back together. Share this post Link to post Share on other sites
bomax Posted October 7, 2005 hey guys iam doing both crank seals right now but forgot my shop manual.do the flat sides face out on both?they were taken out without me present. thx Share this post Link to post Share on other sites
modin Posted February 20, 2006 Have the same problem om my -05. Changed the seals without success. Last time I tried to mount the rt crank seal out side in, but it still leaks. Has anybody had experience with the crank coming "out of true" (or how ever you put in in eng.) on the Hondas? I know that big KTM tends to need welding on the big end pin in the crank to stay "balanced". I'm planning to measure my crank to see that its not wobbling around. If the crank is OK i don't know what to do. /Jonas 👍 Share this post Link to post Share on other sites
