Hey Gang,

I recently purchased a 2007 Grizzly 660 in need of repair, but it has been a real beating. Need a bit of diagnostic help.

It is spitting out a bunch of oil. Where the muffler and head pipe connect, oil steadily drips. Here is what I have replaced so far.
New timing chain
New valve, springs, retainers
New piston rings, yes I offset the ring gaps. Of course gaskets and oil change.

The piston and cylinder jug were in spec so I didn't replace or bore them.
The cylinder head looked good so I thought maybe just some new valves. The center intake valve was bent due to it jumping time. When I put it back together. I checked valve lash 3 separate times before starting. Almost immediately it was smoking and then spitting oil.

What do you think, take the head off and get a 3angle valve job? What do you think is allowing so much oil to pass into the exhaust.

Thanks,
Trent

 

It could be many. many things.
Here is a short list for you:
#1 Broken ring/s.
#2 Bore and or piston out of spec.
#3 Valve guide seals missing or screwed up.
#4 Sump over filled with oil.
#5 Rings installed upsidedown or in wrong position.
#6 Incorrect or blocked sump vent.

If nothing weird is wrong, I think you have ring problems. This is the only way that I have seen an engine pump the amount of oil your talking about.

Do a leakdown. I would be a beer you have a hurricane coming out of the breather.

 

PS: A three angle valve job will do nothing for oil control and has nothing to do with your oil control problem.