Stihl O28 won't run

[96trigger]

Hi, I've got a stihl 028 chainsaw that starts and runs, but bogs terribly when given gas, It has no power to cut anything. I took it in and I was told that it was electrical and it would cost over $200 dollars to have fixed. I'm having a hard time believing that a chainsaw can have $200 worth of electrical in it. I am mecnanically inclined and will now look at doing it myself. Anybody have any experience with this before?

[Sgt. Rock]

With a new plug and good gas if it persists I'd vote for plugged exhaust ports. Not uncommon from too rich a mix.

[Guest]

I have the same Saw and was having a problem last fall like you and it turned out to be just a clogged air filter. Washed it out with gas and let it dry and everything was fine after that.

[Wavey Davey]

Clean the spark plug, clean the air filter, drain the old gas and put in fresh gas with some Seafoam. Run it a while.

Had the same problem recently, pretty sure it was old gas.

[96trigger]

Any idea what the electrical part could be? Its an older 028, It was running fine, I was running the bad stuff out of it when it happened. I put in new fuel and it didn't help. I'm beginning to think that I should have torn into myself a little bit more, I was thinking that I scored a piston, but maybe not, it might be something much more simple.

By the way, I did clean the plug, I did clean the filter, never put in the seafoam, but I do have some at home. I'll try the sea foam. Any reason why it would suddenly start running poor?

[VMS]

If it was instantaneous, it would be one of two things: Electrical, or you got something gummed in the carb jets.

If you replaced the plug, I would look at checking your spark. Take the plug out, and put the plug wire on it, making sure the tip of the plug is touching something metal (like the engine block). Pull the starter. If the spark is weak and intermittent, it could be the plug wire (if it is old, it will build up resistance in the line) or it could go back to the coil/magneto. Not sure if it is old enough to have electrical points, but that would be my next bet... I'd maybe try and trace back on electrical first before tearing into anything else. The sea-foam may help some, since a chainsaw will run such a rich mixture (as was stated), so it cannot hurt to do that as well..

you may also want to trace the fuel line back into the gas tank. On many models, there is a filter at the end of your gas line inside the tank that has foam in it. If this has gotten gummed at all, it will easilly restrict the flow of gas to the engine.

Lots of little things to check and maintain, but in the long run, getting them clean will help the engine overall too.. A good once-over every couple of years really does wonders.

Good luck..

Steve

[Macgyver55]

It sounds like a fuel delivery problem to me. Either it picked up a speck of dirt in the carb or the fuel line may have rotted and cracked in (or near) the tank and it is sucking air. In any case a carb cleaning a new fuel line and filter will probably fix it. If not, post here again. I have an older Stihl 028 AV chain saw that I was going to fix up for up at the cabin, but if it would help you out of buying a 200 dollar part I'd let you have it cheap for parts.

[96trigger]

Thanks, Mac, I've already been on hsolist looking for parts, what has me questioning is that the mechanic said that its electrical, I can't find an electrical part for the 028 that comes even remotely close to what he is saying it would cost. I've seen coils, but they tend to run about 40 bucks. I actually trust this guy, but for the life of me, I can't see where the electrical problem could be, I'm going to pick it back up from the guy and do some more looking. I'll let you know if I need parts Mac, thanks again.

[icegrogg]

96; when you cleaned the air filter,was there alot of gas soaked into it? If so it might be something in the reed valve. TRY THIS: take the bar and chain off,start the saw with filter off the saw,with a small screwdriver slowly turn up the idle screw.IF it runs at this point,try hitting the triger a few times. If it still boggs down you might have to take the carb off. The reedvalve is behind the body. JUST A THOUGHT. GOOD LUCK!!!

[luckyc]

I would check the mufffler also, a lot of the 2 cycle engines have a spark arrestor screen in the muffler and that will carbon up to the point where it won't let the engine suck in any gas. By running out your old gas, it might have been a lot richer mixture just from the gas evaporating over a period of time. Also the seafoam treatment is a good idea, really cleans out the varnish that is on the jets.

[fish2live]

if you want another opinion i know a really good small engine guy in stewartville. his name is jim wilson he's in the book i don't know if he has a business in town but, he use to do all the small engine work in his garage. really a good guy he will shoot you straight.

[hitthebricks]

I agree w/ Sgt. rock, I run alot of Still products and the first thing I do when I have problems is pull or clean the screen in the exhaust ports and it makes a world of difference. The screens are only spark arestors but do build up carbon deposits and cause to much back pressure. HTB

[96trigger]

Ok, I pulled apart the saw, it appears to have a weak spark. Its an old stihl so it doesn't have a spark arrestor screen on it. I checked the hoses, the filters, etc, it all looks good. I'm thinking the guy was right about the electrical, has anybody replaced points, coils and wire before, everything looks easy except the one wire that travels behind the flywheel. I'm not sure what I'm getting myself into if I take that flywheel off, any advice?

[96trigger]

Well, I believe I fixed the chainsaw. I did some more research and found that many of those saws have points that go bad. This was remedied by putting in an electonic ignition module that bypasses the points all together. It started right up after I installed and ran like a champ. Thanks for the info. If anyone else has an older saw that doesn't run right, this is a really easy fix. It took about 10 minutes. Thanks for all the info, it may not have fixed my problem, but after checking all the things you guys told me, I have a much better running saw.