This oil leak has been driving me nuts.
The previous owner said that bike has been crashed on the right side. One of the crank cover (bottom left) bolts snapped and the cover was scratched up pretty bad. Ok, fine.
I've been trying to fix the leak for a few months now.
Here are some pix of the powdered test.
The lower right is the bolt in question. This is 5 minutes into a ride around the neighbourhood. It's bad enough that any oil that's in the case simply leaks overnight. It's not terrible, I do track days on this bike and don't have to top off, but a 2 hour ride today resulted in some oily pattern on the rearset.
It seems to be even leaking through the bolt hole itself.
This is what underneath looks like. This appears after the pic#1.
The leak around the middle bolt appears last.
This, I'm not sure about. When looking at the casing, the cover goes over a joint in upper and lower crankcases. The rear joint between the two is smooth. The front joint (in the red circle, covered by the cover), is not, the cases are offset by don't know, maybe .25mm? Definitely can feel it running the finger over it.
So far I've tried:
- Tighten everything to spec 9Nm
- I've tried to tighten so much that I stripped the threads
- Rethreaded several of the holes with Helicoil
- Lower right bolt has been tightened (with Helicoil) to a point that helicoil broke, and I've since then rethreaded it to 5/16 (or whatever next closest size to M6 is)
- Has Woodcraft gasket
- Tried squirting Hondabond #4 in the hole to stop the leak.
I'm out of ideas at this point. After the powder test, while taking pictures, I noticed that the bolts were slightly looser again, and tightened everything again.
Questions I'm pondering are:
- Did the crash somehow bend something/squash something so I no longer have a tight seal on the bottom?
- Is the offset in crankcase joint causing this?
- I've tried stock gasket, I've tried WC gasket, I've tried just Hondabond.
Can I use both Hondabond AND a gasket around the bolt holes?
- How is it blowing oil out of the lower right bolt?
Any ideas/help is greatly appreciated.