Was taught a hard lesson over a faulty primer bulb

[Fordiesel69]

Did a very thorough carburetor rebuild on a husky 435 chainsaw only to reinstall it, and have the carb throat overflow fuel with each press of the primer bulb. After questioning and ruling out my careful overhaul, I had no other options but to quickly swap in a new primer. That magically solved the problem.

This is the first failure i have had that the internal check valve failed before the actual external bulb.

This is also the first carburetor I have overhauled that looked spotless, had a perfect microscreen that flowed fuel thru speedely, perfect soft metering diaphram, but was bogging regardless of the H screw adjustment. A full carb kit fixed the problem with no explanation of what the actual fault was.

I hate not knowing.

 

[Arc]

Did a very thorough carburetor rebuild on a husky 435 chainsaw only to reinstall it, and have the carb throat overflow fuel with each press of the primer bulb. After questioning and ruling out my careful overhaul, I had no other options but to quickly swap in a new primer. That magically solved the problem.

This is the first failure i have had that the internal check valve failed before the actual external bulb.

This is also the first carburetor I have overhauled that looked spotless, had a perfect microscreen that flowed fuel thru speedely, perfect soft metering diaphram, but was bogging regardless of the H screw adjustment. A full carb kit fixed the problem with no explanation of what the actual fault was.

I hate not knowing.

It's that time of year to be cutting wood for the winter. I've had so many projects going that I haven't even cleaned my stihl 390 and 250 from last years cutting yet. I haven't had a carb failure since I started using non ethanol gas in my chainsaws.

 

[97prizm]

It's that time of year to be cutting wood for the winter. I've had so many projects going that I haven't even cleaned my stihl 390 and 250 from last years cutting yet. I haven't had a carb failure since I started using non ethanol gas in my chainsaws.

Non ethanol definitely. I find that my Stihl FS-38 runs even better on higher octane gas than what's at the local pump. I think the only place local to me with ethanol free is 86ish octane which ran rough. Right now I'm finishing off whats left of 100LL avgas, and now that I can get lead free mogas That's probably next. I thought by now that ope would have fuel lines and components that are resistant to hardening due to ethanol.