The Forestry Forum
General Forestry => Chainsaws => Topic started by: LeeB on May 28, 2024, 01:07:13 PM
Can or will a leaking purge bulb cause a lean out?
If the leak is bad enough, it wont run for lack of fuel all together. Its an easy replace and don't cost too much.
Of course it will. The bulb creates suction to pull fuel in one side of the carb and out the other to fully prime the system. Then engine vacuum pulls the fuel through the carb. If there is air leaking into the system, the engine will pull that along with the fuel and the lean out occurs. It will only get worse over time.
Quote from: rusticretreater on May 29, 2024, 12:36:34 AMOf course it will. The bulb creates suction to pull fuel in one side of the carb and out the other to fully prime the system. Then engine vacuum pulls the fuel through the carb. If there is air leaking into the system, the engine will pull that along with the fuel and the lean out occurs. It will only get worse over time.
Correct and I didn't clarify what I was trying to say, but that's what I meant. Typing while drowsy zzzz_smiley
The bulb sucks fuel from the tank via the filter, through the carb and then back into the tank on a return line does it not? If the check valve is working correctly it should not be able to suck air back through the lines correct? I bought a new bulb today and will replace the old one. I just figured the old one was leaking because it would not pull fuel into the bulb. I'll check it and the lines when I change it.
In a normal situation the primer bulb will not be over half full of fuel.
There was nothing wrong with the car lid bulb. When the old motor on my brush cutter seized up I let my ex son in law swap it out with a short block. He had the lines on backwards and one of those as pinched between the carb and the jug from when he put the carb on.
On that subject there are only two or three normal sizes for replacement bulbs .They are inexpensive .
He also sent it back without an air filter. Put in a new filter today Runs just fine now. Wouldn't run well without the filter..Guess the filter chokes it back just enough to make a difference.