Two stroke fuel pump weak?

[jv9999]

I have a Ryobi BP42 blower (I know...). I understand how two stroke fuel pumping works in general, but this one has me stumped. With a known good carb and an external gravity fuel supply it runs great. Running off the internal tank (new lines, bulb, and filter) it idles fine but chokes out on anything above idle. It seems to have good compression and the transfer port is clean. Is it just tired and no longer producing strong enough pulses? The compression seems good, but I haven't actually measured it yet.
Thanks for any thoughts!

 

[heimannm]

R

Thread 'help understanding 2-stroke fuel pumping'

Jul 6, 2023

kind of a rudimentary question(s), I think I already know the answer some, but want clarification to be sure and a good understanding of the whole process ...

small engine 2-stroke, uses the downward stroke of the piston as a pressurization signal...

- which always goes to carb? this pressurization signal works the fuel pump (thing?) in the carb, how does the carb pump fuel?
- on small engine 2 stroke carbs there's [always?] 2 hose nipples? one is the intake from the gas tank that in fuel into the carburetor that is then metered by the carb and makes its way into the intake of the...

• r7000
• Replies: 32
• Forum: Ask the Experts

Make sure your tank vent is functioning correctly, and work on your terminology, choking would suggest too much fuel yet you seem to say it it not getting enough fuel.

Mark

 

[jv9999]

Tank vent is open. I think the term "choked" can mean either.

 

[Coupe]

Had one of those things I fixed for a mate and what a pig of a carby they have got on them.
It was running to lean the one I worked on so had to slowly tweek the metering lever till
I could get it rich enough to run' If you do it just tweek small ammounts at a time.
Hope that helps.