I have a chainsaw repair question:I have a Stihl 028 AV super chainsaw that I'm rebuilding. The chainsaw had been sitting around for years with gas in it. I had low compression so I changed the piston and rings. I also rebuilt the carb. I cleaned it, but new gaskets on it, and checked the spring and meter. I also checked the fuel line and impulse line with compressed air and they both look good. After doing all this I thought I'd be good. However, I cant get it started. I can spray carb cleaner in carb and can get the saw to fire but only with the carb cleaner in the cylinder. After that burns it doesnt continue. I'm stumped. Any suggestions?
Country: United StatesMake: StihlModel: 028 AV superYear: 2000
Hi, My name isXXXXX you for letting me try and assist you with your problem.The symptom you're describing is that of a sticking needle valve inside the carburetor.That's the part that lets fuel into the carburetor. If it's sticking closed you're essentially running it out of gas. Since it only runs on the carb cleaner that's actually a good sign that everything but the carb is in good shape.I would pull the carb off and go through it with carb cleaner and compressed air to clean it.Make sure you take a picture of the linkage before you take it apart so you know where to set it when you put everything back together.With every screw you should turn them in until they seat lightly counting the turns it took to seat them.Make a note of it so you know where to set them when you put the carb back together.You need to spary carb cleaner through every single hole you can find to make sure it's clean.
I've taken the carb apart, cleaned it with carb cleaner, and compressed air, and it looks pretty clean and all the wholes and screen look good. The spring and meter look good as well. What linkage are you referring to? Ive gone through the carb about a half a dozen times because its got to be something with that, fuel line, or impusle line but still not working.
Did you happen to put a new diaphragm in it?The linkage I was referring to is just the throttle linkage. Some folks get confused on how that works.It could be the fuel lines too can you see that the feed line is still connected and not stiff or cracked inside the tank?
Yes, I replaced the diaphragm. The fuel line and impulse lines look good, no cracks, or stiff and connected properly.
Does the carb have a primer bulb on it?If it does will it pump fuel through the carb?
No primer bulb. And after I install it, and then reassemble it, there doesnt appear to be any gas in the carb.
That makes it sound like the carb is working but it's sucking air not gas from the tank.Are you sure the lines are right? Maybe try and switch them around to see if that fixes it.
The lines are tight. I just bought a new on ebay a new fuel line and fuel filter. Hopefully that will solve it.
It sounds like your fuel filter may be plugged up so I'd say you're doing the right thing.It's all that's left if the carb is functioning.
15+ years of experience and a business owner.