Stihl 028 AV spitting fuel

[jjdlc]

This is something I've not run across before, at least in a piston ported saw. I've seen similar in reed valve saws where something was keeping the reed from sealing good.

Was given a 028 AV, the thing is very clean, will start, but spits fuel out the carburetor like crazy, won't rev. Was given an AM carb with it, went ahead and cleaned and rebuilt the OEM, but it acts the same either way. Compression is just shy of 160, vacuum and pressure tests are good. I ran out of time to work on it Saturday, but it's been bugging me since. I'm planning to tear it down, and was just hoping to get some ideas on what to look for. I'm thinking maybe some piston wear/damage that isn't apparent from the outside, but just wondering what else might cause this behavior. Thanks in advance.

 

[KYsawman]

If it is the very early model it has points ignition and as the points wear it will spit back. I had one and fought it till I switched to solid state coil. It is an easy up grade.

 

[jjdlc]

If it is the very early model it has points ignition and as the points wear it will spit back. I had one and fought it till I switched to solid state coil. It is an easy up grade.

Thanks for the input, I probably wouldn’t have even thought to look at that. The spark looked good. I’ll have to see which version it is.

 

[jjdlc]

If it is the very early model it has points ignition and as the points wear it will spit back. I had one and fought it till I switched to solid state coil. It is an easy up grade.

Hey, just wanted to say you nailed it. Got my module today, and the saw is running great. Many thanks for the hint.

 

[KYsawman]

Hey, just wanted to say you nailed it. Got my module today, and the saw is running great. Many thanks for the hint.

Your most welcome, that is what I love about this forum is that someone has probably had the problem before and is willing to help! I always try to pas it on. Glad you got it running good. The 028 is a great saw.

 

[usmcbuckwild]

Good info here