14-year-old weedwacker engine having problems

[Deathfire138]

I got it to run pretty good now, after some low-rpm tuning. I'm waiting to do the high simply because I have only flathead screwdrivers and they'll just vibrate right out of the slot at full throttle if I try. The last time I ran it while tuning it, I put the air filter and filter cover back on and it didn't seem to have any gas on it, which is very good news.

 

[Deathfire138]

Sorry for double-posting but I can't edit my last reply.

Okay, so I found this new problem with it. I tuned it a couple of days ago, as you know, and it worked pretty good. A few days later it was out of tune. The screws didn't seem to have moved at all and when I re-tuned it I noticed that it was very finnicky and inconsistent. I'm not sure what's wrong, but I did notice this little mesh-like filter thing that apparently filters the fuel before it exits the carburetor. It's a bit gunked up. I have a new one in the carb kit I bought but I haven't a clue how to replace it, does anyone know how and/or what might be wrong with the tuning?

 

[660mag]

If the mesh thing your talking about exits into the venture of the carb than that is the main check valve. Not easy to swap out. Might even need a press to do it. Trying to suck/blow through it is your best bet. Use a bit of fuel line and press it firmly to it from one side suck/blow, and then the other side using seafoam or something like it as a cleaner. If the diaphragm has not seen fuel in a while that explains the need for retuneing. As the diaphragm softens up it will pump more and more fuel. Good luck.

If it fails to pull through for ya. Get you a stihl fs45. There not pricey and a new carb for it is only about 33bucks.

 

[Deathfire138]

Think I could blow compressed air from the side that's clean until it all blows out the other side, or should I be more gentle/is there a one-way valve there...?

 

[660mag]

It is for sure a one way valve. Compressed air is too much. It only should flow from the service plate into the venturi, but not the other way. If it flows both ways than the unit will dump full fuel as long at the crank case is pumping the carb.

 

[Deathfire138]

Originally Posted By: 660mag
If the mesh thing your talking about exits into the venture of the carb than that is the main check valve. Not easy to swap out. Might even need a press to do it. Trying to suck/blow through it is your best bet. Use a bit of fuel line and press it firmly to it from one side suck/blow, and then the other side using seafoam or something like it as a cleaner. If the diaphragm has not seen fuel in a while that explains the need for retuneing. As the diaphragm softens up it will pump more and more fuel. Good luck.

If it fails to pull through for ya. Get you a stihl fs45. There not pricey and a new carb for it is only about 33bucks.


I'm pretty sure that when I replaced the diaphragm is was about as soft as it was going to get, and I don't see how gas could make it softer. By the way you worded your sentence it seemed as though you didn't know I replaced the diaphragm with a new one.

Originally Posted By: 660mag
It is for sure a one way valve. Compressed air is too much. It only should flow from the service plate into the venturi, but not the other way. If it flows both ways than the unit will dump full fuel as long at the crank case is pumping the carb.


I'll try to suck it out and see what happens...

 

[660mag]

The diaphragm and the main check valve are two different things. The diaphragm is the part the came in your kit most likely. Most kits do not include a main check valve. The diaphragm is the 1 inch by 1 inch black rubber covered silk square with a metal ring in the center (the fuel pump). The main check valve is only about 3mm across.