Stihl 075 Vapor Lock ?

[Timber_Hitch]

I was wondering if anyone has had a similar experience with big Stihl saws. I made about 8 fast cuts through a 40"er Oak.
I sat the saw down for a minute to talk to a neighbor, then when I tried to start the saw it tried to start but couldn't stay running. I thought it might be out of fuel so I removed the gas cap and to my surprise bubbles everywhere !
was it boiling the fuel was there somekind of back pressure event going on ? I just picked this saw up and rebuilt it reconditioned cylinder new piston & rings.
Help !!!
:bang:

 

[Lakeside53]

Foaming gas is normal - vibration does that and it's the fuel filters job to pick the gas up. Vapor lock is not an issue with these saws.


Hot restart issues - pressure test the carb. These old carbs can have worn carb bodys and the needle valve wont seat properly. It allows gas to siphon though the carb and into the cylinder, giving an over rich condition for a hot start.


Did you manage to get it going again when cold?

 

[Timber_Hitch]

Yes the saw started good today ran strong worked it hard but not as hard as the day it acted up. The saw was off when the gas was bubbling. I layed the saw down and it continued to smoke near the muffler, so I got an air gun and blew out around the muffler and damm if there wasn't some burning glowing chips coming out of there. There must be a chip trap near some area that can ignite. I am sawing up dry slab for my outdoor wood boiler so the dry wood probably dont help.

:monkey: