81 SOHC Smoke Show.

[Megalomaniac]

The bike started spitting blue/white smoke out of the exhaust, under the following conditions:

Deccel/Downshift
Blipping the throttle after a downshift
Hard Accel

I'm leaning towards it being the oil control rings but is there any chance it could be something else before I take the bike down?

 

[xschris]

Valve seals and or guides.

 

[Megalomaniac]

I was able to easily wrangle the valve cover off, but I can't seem to find a decent spring compressor (locally) anyway that I'll let me depress the valve springs with the head still on. Any suggestions for compressors or is my only recourse to pull the head off also?

 

[rshutchinson]

Either way you look at it the head has to come off so just take it off.

 

[Megalomaniac]

At that point would it also be easier to pull the cylinders and re-do the oil control rings?

Or is the likely hood of it being the oil control rings low enough to not warrant replacement?

 

[Megalomaniac]

Said bugger it and ordered the piston rings, might as well only have to go in once and call it a day.

 

[Megalomaniac]

Looks like the issue is more than just a "little smoke", Cylinder is trashed, right side of the right piston is trashed, rod has play up and down and side to side. Maybe its time to part out and move on.

 

[rshutchinson]

Is the circlip still there holding the wrist pin in on that piston? Looks like the pin has slid out to the side.

 

[Megalomaniac]

The circlip on the right hand side of the right hand piston dis-integrated, I found what might be pieces of it after running the oil through a coffee filtre.

I decided to pull the pistons and found that the left hand circlip on the left hand piston was also broken into two pieces but still holding, so that side was only a few rotations away from gouge city.

It looks like the way this broke it jacked the piston against the crank and wore out the bearings on the right hand side but the crank itself didn't walk.

Oddly enough there was no odd/strange noise from the motor during any of this.