Chainsaw Won't Start

[drssg]

I would think this has been discussed before, but my search of old threads didn't find anything that seemed to match my circumstances.

I have a Stihl MS 290 that is about six years old. The last time I used it was during the winter, and it worked fine. Now, I can pull the cord until my arm goes numb, and there's no sign of life.

My best guess as to the root cause is that I'm an idiot. I didn't run the gas out of it last time, and I suspect it's gummed up. I've gotten lazy about this, because I've done it before, without paying consequences.

I'm debating whether I should just take it in vs. try to fix it myself. I've never done small engine repair, but I have a little bit of mechanical aptitude. Are there any fairly simple things anyone can suggest I try, before I pay someone who knows what he's doing?

 

[Egon]

Keep pulling, clean the plug, clean the air filter, put in new fuel mix, learn some new words, open the jets a touch, make sure you forget where they were set, close the jets, open them again, use the choke, don't use the choke. pull when at full throttle, pull when at idle, learn more new words, check the manual, keep pulling. It may start! Buy a bottle of Canadian Club and forget about the durned thing!

 

[drssg]

Dang! I guess I'm smarter than I thought. I've already tried several of those ideas. I'll try random jet adjustments next.

 

[dmccarty]

Well, I messed up on my Stihl 046.....

Same story as yours....

Except that I had a gallon of oil/fuel mix from last Nov/Dec. Said what the heck its supposed to have a stabilizer. So I tried it. I knew better.

Long story short it would not start. Had to pull the plug. Found out I DID NOT have a spare like I thought so I ran into town and got the LAST plug in stock.

Put in the new plug with new fuel mix and it started somewhat right up. Its still not quite right, it almost stalled out twice on me when it was ideling which has never happened before. I'll be working with the saw this weekend so we shall see what happens. Should not be the spark plug. It was a special fancy dancy $5 plug. Not the usuall $2 plug.

Need to stop at NAPA and get a few more $2 plugs.

Later,
Dan

 

[RobertN]

I would think this has been discussed before, but my search of old threads didn't find anything that seemed to match my circumstances.

I have a Stihl MS 290 that is about six years old. The last time I used it was during the winter, and it worked fine. Now, I can pull the cord until my arm goes numb, and there's no sign of life.

I just did repairs to my Dad's older Stihl 024AV. I put fresh gas in, and pulled a number of times. Pulled the air cleaner; did need some cleaning, but was ok. Pulled the plug; fairly new and a hot spark, but dry as a bone.

Pulled the fuel line to the carb; no gas... Went to empty the gas tank, and the fuel filter fell out. The filter was pretty dirty, but the worst was the feul line had rotted out.

Flushed the tank, put in a new fuel line and filter, and a new plug while at it. Runs great!

Might be worth looking at...

 

[jinman]

If leaving gas in a chainsaw could hurt it, mine would never start. I swear I never run my Stihl dry and just leave it for months. I add gas and pump the bulb 7-10 times, choke it, and it seems to always start in 4 or 5 pulls at the most. Actually it trys to fire once with the choke all the way on and then I put it to half-choke to get it to fire off. That little Stihl 029 has spoiled me rotten.

On most two-cycles, I find that they are nearly impossible to flood. If you pull the plug and it is not wet, it's probably not getting enough gas. Heck, I've poured a stream of gas right into the carburetor inlet on another old saw to get it to fire. I'd bet fuel delivery is your problem.

 

[RonMar]

Yep, plug wet or dry is usually the first thing I look for. If wet, you are most likley missing spark, or the plug is fouled or shorted(passing current but not sparking). Plug dry, and you are missing fuel. Most wedeater and chainsaw carbs these days are diaphram type and do not really keep much fuel up in the carb like the older float bowl type still seen on many lawnmower engines. It will usually evap pretty cleanly with out turning to crud inside. Adjusting the high speed and slow speed screws is probably not going to help you at this point. If it was running fine the last time you used it, leave em alone, adjusting them blindly may keep it from starting once you get the current issue resolved, and will surely mean you have to re-tune the engine after you do get it running. You said you don't have much small engine experience, and an improperly set high speed screw(too lean) can fry a 2 stroke engine, even to the point of melting holes in the top of the piston.

If you don't have a priming bulb(best thing since sliced bread for small 2 stroke engines), you can try putting a little fuel/oil mix down the carb opening with the air filter removed to get it to fire initially and help get some fuel to be drawn up from the tank into the carb. The diaphram pump in the carb draws fuel up to the carb using energy from the pulsed airstream thru the carb. Getting it to run, even a little is way more effective than the pulses generated from pullstarting. There should also be a vent pipe for the tank to allow air in to replace the fuel being drawn to the carb. It will either be in the cap, or will be a second hose in the tank that either goes into the air filter housing, has it's own filter element, or goes into the block. Make sure it is clean. Sometimes a little gentle air pressure applied to this vent(attach a piece of vacume hose and blow some air in by mouth), can help prime a finiky carb. But if they won't prime on their own, this usually means a problem with the diaphram.

Jinman described the ideal starting procedure. Full choke till it pops, then half choke for the next pull. Ususlly starts right up. I run half choke till it starts to run rough, as it warms, and ruduce choke as needed till warm.

Good luck

 

[MossRoad]

...

Jinman described the ideal starting procedure. Full choke till it pops, then half choke for the next pull. Ususlly starts right up. I run half choke till it starts to run rough, as it warms, and ruduce choke as needed till warm.

Good luck

I agree. I also suggest one very short blast of starting fluid in the carb first. If it pops you know you have a spark and it is most likely a fuel delivery problem. I have never, ever had fuel go bad in anything and I have left things for several years with fuel and they still fire up. Fuel filters, fuel lines give me more problems than anything.

 

[studor]

I have an MS290 and have never taken the gas out and it has always started using the process outlined by others. You might want to just dump out what is in there, put in fresh and check the plug -- I would not play around with the jets .

(Course -- could be you -- I have a buddy that if he gets within ten feet of a two cycle it either won't start or won't run -- over a period of thirty plus years a number of us have observed this capability in him )
I too have poured gas directly into the carb of some saws to get them going -- it works.
Failing all of the above practice that new olympic sport -- the dead chain saw toss and curseing competition -- you only win if you go back to retreive it and it starts

 

[Hookblock]

Just tell me what dumpster your going to throw it in, I don't have a 290





Trash to treasure

The Little woman went to the recycling center tonight, I had to work late. She got to the metal dumpster looked inside to put some stuff in it and saw what she thought was a stihl chain saw, and it was. So she grabbed it, Thinking we could use it for parts. We started looking it over and and didn't see anything wrong with it, pulled on it, sounded normal, checked the gas, smelled bad, replaced the the gas, cleaned the air filter. Checked the carb adjustment screws, set the carb shield to summer setting. Put the choke on pulled 2 times it popped, went to mid choke pulled 4 times it smelled flooded, flipped it to run opened the throttle pulled 3 times it took off I put a bar and chain on it and cut up a downed tree I had been putting off for awhile. The saw ran great