TTR 90 big bore problem

[Phil67]

Too much oil in the case?

 

[ttr90man]

No i have checked and changed the oil 800ml is spot on ?

 

[Phil67]

So it smokes on de acceleration? That is valve stem seals

On acceleration = rings

 

[ttr90man]

It just a little strange it only started doing it after the big bore kit, ill order some and see if thats the prob , they have never been done from new , so it cant hurt .

 

[my67xr]

could also be worn valves guides in the head if it's done a few kms/miles?

the semi synthetic may not be letting the rings bed in properly too?
did the bore look like it was glazing?
and what clearances are you running on the valves/rockers?

 

[my67xr]

were all the piston rings' gaps were staggered?

 

[motodevo]

It just a little strange it only started doing it after the big bore kit, ill order some and see if thats the prob , they have never been done from new , so it cant hurt .

The bbk will have increased the pressure in the crankcase. The stem seals might have been a bit worn already but not noticeable but the extra pressure from the bigger piston will push more oil past seals than the original piston. I'd switch to a mineral oil to let the rings bed in as 125psi is alot lower than i'd expect on a new top end and lean out your carb abit if its rich rich like you said, if its too rich those rings wont ever bed in right