View Full Version : Poulan Pro only runs at full choke


ihate2cycles
08-09-2010, 09:55 PM
Hello everyone. I have a Poulan Pro PPB335 trimmer which has been giving me trouble the past few weeks.

It started off bogging down somewhat under throttle, so I decided to take it to a shop to have it looked at. Well, a couple weeks later, after finding out no one locally will work on it, I decided to do it myself. I mean, I work on cars and stuff, how hard could it be?

Apparently a lot harder than it looks! I tried different gas, no luck. Then I rebuilt the carb, no luck there either! When I changed the gas, it started doing something different. It only runs at full choke! It runs at a midrange rpm, not idle but not wide open either. It will run at full choke for a least 3-4 minutes before dying. If I move it to half choke or open, it dies almost immediately.

It has a Walbro WTA31 carb, cyl compression is 115.

Any ideas?

30yearTech
08-09-2010, 10:24 PM
A dirty fuel filter in the tank.

Bad fuel hose.

Air leak into the crankcase.

Faulty high speed check valve in the carburetor.

Just to name a few. check all around the crankcase and make sure all attaching hardware is tight. A small air leak can cause these issues and is somewhat common on these engines.

ihate2cycles
08-09-2010, 10:37 PM
Whoops, left out a few things. Thanks for reminding me, lol!

Fuel filter is good, as are hoses. I'm leaning towards air leak, since I rebuilt the carb. This thing isn't even a year old yet, still under warranty (well it was until I opened it up!) but I didn't even think to send in the warranty card. Usually everything I buy breaks right after the warranty, bad decision on my part.

geogrubb
08-10-2010, 08:07 PM
Whoops, left out a few things. Thanks for reminding me, lol!

Fuel filter is good, as are hoses. I'm leaning towards air leak, since I rebuilt the carb. This thing isn't even a year old yet, still under warranty (well it was until I opened it up!) but I didn't even think to send in the warranty card. Usually everything I buy breaks right after the warranty, bad decision on my part.

Try spraying/dribble some carb/brakeparts cleaner, using the straw, behind the carb along the mating surfaces, if the engine tempo changes you have a leak. Have a good one. Geo

ihate2cycles
08-11-2010, 08:43 PM
Sure enough, the gasket between the carb and motor is leaking. Now I need to try to find a place around here that has it. If not, I'll just get it online.

Thanks for the help!

geogrubb
08-11-2010, 10:00 PM
Sure enough, the gasket between the carb and motor is leaking. Now I need to try to find a place around here that has it. If not, I'll just get it online.

Thanks for the help!

You probably should order 2, I have found some of the aftermarket gasket material to be very thin, just don't block the pulse port if you pair them up. Have a good one. Geo