Fuel flooding in to cylinder - Craftsman

[LesPro]

I purchased a Craftsman (yes I know) chainsaw at an auction a while back. I've replaced the primer bulb, fuel lines, and filter. It's always been difficult to start but now I've got a new problem. When I go to pull start it - it has a large amount of fuel in the cylinder. I pull the spark plug out and out comes a good 1/8 cup of fuel. Now this is before I even touch the primer bulb. This happens as it sits.
I have owned a few Poulan Pro saws and this saw seems built nearly identical, and I've never had this happen to a Poulan Pro.

Any idea why?
Any idea what I can do to correct this?

 

[J D]

My guess would be the metering valve is stuck open & unmetered fuel us being drawn straight through the carb

 

[LesPro]

Thanks JD. I don't know much about carbs but I do have one or two spares. I might just try replacing???

 

[ammoaddict]

Thanks JD. I don't know much about carbs but I do have one or two spares. I might just try replacing???

If you have a known good carb, that's where I would start. If it's a walbro carb, they have rebuild instructions on their website.

Sent from my moto g(7) power using Tapatalk

 

[J D]

If your other carbs are the same it's worth a shot. Bare in mind you may just be swapping 1 set of issues for another.
If the carbs have been sitting around for a while or are just in unknown condition & the covers will come off without destroying the gaskets I'd at least check the diaphragms are still supple & aren't deformed & the filter mesh is clear.
You will need to retune the saw

 

[Old2stroke]

Is the primer bulb correctly connected so that it suck fuel OUT of the carb? If it is connected backwards the check valves are pointing in the wrong direction and any shaking of the saw will pressurize the fuel tank and force fuel through the bulb directly into the metering chamber of the saw and out of the low and high speed circuits.

 

[cookies]

Is the primer bulb correctly connected so that it suck fuel OUT of the carb? If it is connected backwards the check valves are pointing in the wrong direction and any shaking of the saw will pressurize the fuel tank and force fuel through the bulb directly into the metering chamber of the saw and out of the low and high speed circuits.

I often see this and when tried to run like this results in damaged diaphragms and check valve. The cheap-o 30-40cc poulan/craftsman/homolite/husqvarna home owner saws that are all poulan design have a under sized zama carb and its less than desirable. I found a couple of the chinese knockoff carbs to be far superior in longevity, performance, less temperamental and simply better at fine tuning. I use the hipa brand carbs on these saws, be warned they have come with bad pump diaphragms in the past so i order kits with them now.

 

[dboyd351]

If the primer bulb is routed incorrectly it doesn't matter whether it is the cheapest saw made or the most expensive, it still won't run correctly.
Has nothing to do with it being a cheap saw - it is the result of someone unknowingly forcing the saw to flood itself by hooking up the fuel lines backwards.
Most people mistakenly assume the primer bulb should force gas into the carb, but in reality they are designed to pull fuel through the carb and put in back in the tank - a matter of purging the fuel line of any air so the carb can correctly pump fuel itself, not forcing fuel into it.

 

[ChillyB]

Bought two Poulans with plastic cases from a dude who was tired of messing with them. Fuel lines were new, crumbly bits of old hose under the air filter. BOTH saws had fuel lines rounted to pump the carb (and crankcase) with fuel. Fixed that and both saws run.

One is a Wild Thing, yet nobody nominated me for You Suck credentials. Jealousy is an ugly emotion.

 

[dboyd351]

Yep, some people blame it on the saw being "a piece of crap". But the problem isn't the saw, it is the "mechanic".


You do know you SUCK, don't ya?

 

[ChillyB]

Yep, some people blame it on the saw being "a piece of crap". But the problem isn't the saw, it is the "mechanic".


You do know you SUCK, don't ya?

I knew I sucked when I signed up for this forum but an admin let me in anyhow.

 

[Okie]

Replacement carbs in a tune up kit with gaskets, fuel lines, primer bulb and spark plug is usually available for them Craftsman/Poulans for less than $20. Check flea bay using your model number.
Post up a Model number.

You can find lots of You tube videos about how to replace the fuel lines and correct connections for the purge bulb.
Right now you have a bad carb.
When all is correct a Craftsman/Poulan with a purge bulb primer usually starts easily.
(and connecting purge bulb fuel lines backwards is not your severe flooding issue)

 

[Vintage Engine Repairs]

If you are getting fuel in the crankcase, your metering needle, for whatever reason, isn’t sealing. Pressure builds in the tank and it forces fuel through the carb and out into the Venturi and thus ends up in your crank.

 

[Old2stroke]

If you are getting fuel in the crankcase, your metering needle, for whatever reason, isn’t sealing. Pressure builds in the tank and it forces fuel through the carb and out into the Venturi and thus ends up in your crank.

Right. This is why a flooding condition should be fast to resolve, just have to pull the fuel line off the carb and pressure test the input valve to see if it is sealing and that the pop-off pressure is at least 10psi.