Glad you got it sorted

great news, was it the float bowls?

 

compression is better warm btw, but you may find you have gummed rings which will free when you use the bike more.

 

bike should get better as you use it

Yes, it's the separate passage in the float bowls that supply fuel to the choke. Only two are good. That's why rev comes back down after I put the choke on.

I'll do a compression test later after the bike warms up.

So far, everything seems just fine and it starts easily with the choke on even when it's at 2 deg C.

Do you know if the compression at 156 psi specified by the factory measured in cold or hot engine?

Cold, cold is cold. Hot has too many variables, like valve clearances are normally done cold. Yes there are rare exceptions but your going, not might, going to burn yourself.

Figure within 10-15% of that figure is fine, more important they should be all broadly the same. If one is different to the other 3 by say? 25psi, that would sound warning bells.

I did the compression at hot and they are all at 150+.

They were all at only 120+ at cold when factory standard is 156. I'm all confused. I guess there is nothing to worry about if the compression are all at 150+ when hot, right?

yep, sounds ok to me