[493_brandon]

I just put a brand new 493 big bore with a je 12.8:1 piston and it smokes on start up then stops when warmed up,did compression test and came back with 170psi and only leaked down to 165 then stopped so I have no clue what’s wrong

 

[tylerltr450]

Did you seat the rings? it takes a little bit of time.

 

[493_brandon]

Yes it has about 3 hours not new top end and still smokes on start up and smells like oil

 

[Judsteele]

Might wanna start over. Re ring it and go from there. How to you break it in? Did you use motomans directions? And ride it like you stole it? That is how I did mine 2 yrs ago and no issues. Also try out the Facebook site there’s a lot of ppl on that site vs this one. Lotta good info and help.

 

[493_brandon]

yes I did 2 heat cycles then rode it like I stole it but it also holds compression at 170 over night and didn’t move so seems like the rings seated

 

[sandfreak4life47]

I just put a brand new 493 big bore with a je 12.8:1 piston and it smokes on start up then stops when warmed up,did compression test and came back with 170psi and only leaked down to 165 then stopped so I have no clue what’s wrong

some things to consider. make sure your crankcase breather hose is not pinched, valve stem seals could be worn or even the valve stems could be worn, Ring gaps should of been checked , and orientated correctly. while the motor is warming up metal expands So things will seal better.

 

[493_brandon]

Alr I’ll check the breather hose but it has brand new valve seals didn’t check ring gap but made sure they were on the piston right the way it said to put them with the paper that came with the piston I think I’m just going to re hone it and go with a 13:1 wiesco

 

[tylerltr450]

Sounds like ring gap can be the issue.
Did you install the rings upside down?