Sthil ms660 Help

[Lockwood]

Hi ,all I have  a fully rebuilt 660 that will only run when on its  side,It has new carb,impulse line fuelpickup ,coil, seals ,bearings etc.I have tried another carb off a running saw no difference.
I rebuilt the saw after running it over with skidder I am out of ideas if anyone has any I'll give it a go 
Thanks 

[Tom King]

Only on one side, or either side?  If one side, I'd guess the crank seal on the down side.

[Lockwood]

Thanks Tom King ,the seal did cross my mind ,and should of added it will run fine oneday and the next only on its side tried it this morning and no good went out after reading your post to check which  side and it ran perfect ,she might have to go back under skidder wheel.

[Mad Professor]

Hi ,all I have  a fully rebuilt 660 that will only run when on its  side,It has new carb,impulse line fuelpickup ,coil, seals ,bearings etc.I have tried another carb off a running saw no difference.
I rebuilt the saw after running it over with skidder I am out of ideas if anyone has any I'll give it a go
Thanks

Sounds like a bad seal.  Time to get out the Mity Vac and do a pressure/vac test