2 Stroke Flooding issues...

[Rescue1]

Hello all, I apologize if this offends anyone as this mostly doesn't have to do with a chainsaw, but I like the technical expertise here and this problem is driving me nuts.. With that said...

I have an older IDC(I believe that's Ryobi) Tiller. It has sat forever, so the fuel lines and diaphragm rotted. Replaces every line, external primer bulb, soaked the Walbro carb in 2+2(best carb cleaner) overnight, blew the ports out with compressed air, and properly installed a Walbro rebuild kit. I didn't remove the welch plugs however those ports seemed clear with air pressure. New plug as well, and good compression.:confused2:

Went to start er up and it floods, probably the worst I have seen. Figured maybe that metering lever wasn't set right, but it was with good needle movement. Nothing seemed to help.. So I had a trashed cylinder Poulan chainsaw lying around and it had a similar carb. Had to change the throttle shaft, and remove the choke butterfly(original didn't have one, had some weird choke setup). Used all the new parts as stated above, and I have the same result. It's too the point where I clamp the line with vice grips, dry the plug, it will start and run good until it runs out of gas, but as soon as it starts and I remove the grips it stalls immediately. I can "milk" the engine running to a point if I pinch and un pinch the fuel line with my finger. It's a really odd problem, and if there is any internal engine damage it will be in the scrap pile. Any help would be really appreciated as I have never experienced this strange issue.. :msp_thumbdn:

P.S.- Lesson of the day, even though it costs a bit more initially, ALWAYS buy the better brand, be it STIHL, Husky or whatever. This cheap China junk is, well Junk...

 

[ndlawrence]

Hello all, I apologize if this offends anyone as this mostly doesn't have to do with a chainsaw, but I like the technical expertise here and this problem is driving me nuts.. With that said...

I have an older IDC(I believe that's Ryobi) Tiller. It has sat forever, so the fuel lines and diaphragm rotted. Replaces every line, external primer bulb, soaked the Walbro carb in 2+2(best carb cleaner) overnight, blew the ports out with compressed air, and properly installed a Walbro rebuild kit. I didn't remove the welch plugs however those ports seemed clear with air pressure. New plug as well, and good compression.:confused2:

Went to start er up and it floods, probably the worst I have seen. Figured maybe that metering lever wasn't set right, but it was with good needle movement. Nothing seemed to help.. So I had a trashed cylinder Poulan chainsaw lying around and it had a similar carb. Had to change the throttle shaft, and remove the choke butterfly(original didn't have one, had some weird choke setup). Used all the new parts as stated above, and I have the same result. It's too the point where I clamp the line with vice grips, dry the plug, it will start and run good until it runs out of gas, but as soon as it starts and I remove the grips it stalls immediately. I can "milk" the engine running to a point if I pinch and un pinch the fuel line with my finger. It's a really odd problem, and if there is any internal engine damage it will be in the scrap pile. Any help would be really appreciated as I have never experienced this strange issue.. :msp_thumbdn:

P.S.- Lesson of the day, even though it costs a bit more initially, ALWAYS buy the better brand, be it STIHL, Husky or whatever. This cheap China junk is, well Junk...

I don't care what name brand it is, if you run ethanol crap in it and let it sit a long time your going to have problems. That said, I would pull the welch plugs and clean there and sounds to me like your metering lever is stuck open

 

[Rescue1]

You are sure right on the damn ethanol crap. A chainsaw is one thing, but a boat is another beast when you are stuck on the water...


Anyway, oddly enough Ethanol wasn't the issue here because it's been sitting since the "good old days". And really, like you said the metering valve is the only thing that will let that much fuel through. But to do it on 2 different carbs? Well anything is possible. At least it's worth a few bucks in scrap to help pay for the carb kit..LOL..

 

[CTYank]

Tell us exactly what you used as "compressed air" please. Could have done damage to the bits residing behind the welch plugs.

Seems like you have big problem with inlet valve/seat and/or fuel being sucked directly into crankcase via the pump chamber.

 

[Rokon]

I'm no ex-spurt, but I am thinking there is pressure building in the gas tank somehow.

May want to try running with the cap loose or even off. If that works check for a plugged tank vent or an obstruction somewhere.

If this doesn't work then I have proved I know nothing and am no help at all.

 

[Rustynutz]

Using compressed air in these small carbs is a big NO NO
some have tiny none return valves that can be damaged

Here is a link to a piece i did on testing, diagnoses and repair

http://www.arboristsite.com/chainsaw/148347.htm

have a read and see if that helps

Cheers

 

[russhd1997]

I'm no ex-spurt, but I am thinking there is pressure building in the gas tank somehow.

May want to try running with the cap loose or even off. If that works check for a plugged tank vent or an obstruction somewhere.

If this doesn't work then I have proved I know nothing and am no help at all.

On a normally functioning fuel tank vent system the tank is supposed to build up pressure as the fuel vaporizes. The vent and the needle valve in the carb seal off the fuel vapors form getting into the engine and atmosphere when the engine is not running. A clogged or sticking fuel tank vent won't let air into the tank as the fuel is sucked out when the engine is running. This will cause the engine to starve for fuel and stall.

 

[McCulloch1-52]

I don't like this when this happens I been there this road a lot of times it is a nightmare, it got to a point were I give up on it, first change to a hotter spark plug and check vaccum line for gas if it has one if it has gas in it fuel diaphragm is broke, set the low speed needle clockwise to it stops and turn counterclockwise quarter of a turn out pull on it if noting a other quarter turn out if it floods check reeve valves if it has them. The hotter spark plug if for troubleshooting only, use the right spark plug for using.