Stihl ms 290 Farm Boss questions

B_Strange

Member
Hi folks. So I have the saw in the title, I know it is a “cute” saw, but until I can get a 461 it will have to do.

I rebuilt the carb today and replaced the spark plug. The saw ran like a champ while cutting my notch and then died as soon as I started the back cut. I let the saw sit, it cooled off and started great. Rinse and repeat. Now it will not start at all. I ended up finishing the job with my friends ms 170.

I am using a fresh ethanol free gas mixed with the Stihl oil.

Any tips or tricks? Swearing at the saw did not work.
 

Jehinten

Well-Known Member
I own a 290, its actually the first stihl I ever owned, given to me by my Grandpa years ago. It's a little over 30 years old today.

Any time you work on something and then a new problem occurs it's almost always tied to what you were working on. It's most likely caused by your carb and could simply be carb adjustments.
 

B_Strange

Member
Thanks guys! I reread my post and realized I left out the reason why I rebuilt the carb. I ran some True Fuel through the saw, one tank, and when it went dry I put ethanol free gas in it and the saw would not start. My local saw shop recommended the carb rebuild and spark plug replace to fix. It worked until the problems above. Once the saw warms up it just quits. I really like this saw. It is the first chainsaw I ever used. I’ll check spark and my carb work to see if I did anything wrong. I really appreciate the tips guys!
 

B_Strange

Member
Hi folks. I have spark and checked my carb work. Both are fine. I screwed both the H an L screws clockwise till the seated and then backed the L screw out 1/4 turn CCW and the H screw out 3/4 turn CCW. No joy on either full choke, 1/2 choke or no choke. Very stumped. Any ideas?
 

New2trees

Well-Known Member
Not familiar with that saws specs (maybe someone with more knowledge can chime in), but most saws the high and low both back out about 3/4 turn as a starting point, I would try that first.

Also are you sure the impulse line is attached and that the fuel line is not obstructed in some way?

To check if its fuel related (pull the chain for safety) and then add a little fuel to the carbs throat and hold the throttle open and pull the cord till it starts revs up high and dies....if it will not start by adding fuel to the engine manually then its not a fuel delivery issue.
 

B_Strange

Member
Not familiar with that saws specs (maybe someone with more knowledge can chime in), but most saws the high and low both back out about 3/4 turn as a starting point, I would try that first.

Also are you sure the impulse line is attached and that the fuel line is not obstructed in some way?

To check if its fuel related (pull the chain for safety) and then add a little fuel to the carbs throat and hold the throttle open and pull the cord till it starts revs up high and dies....if it will not start by adding fuel to the engine manually then its not a fuel delivery issue.
Thanks! I will try that on Saturday (my next day off). I appreciate it!
 

dirter

New Member
Here is the procedure for setting the carb on a 261. It's probably very similar to the 290. Of course this is with limiters out of the way.

Every time I've had an engine (not just saws) start and run good cold then bad or not at all when warm it turned out to be the coil. When cold everything is tight. When warm everything expands. If a wire in the coil is broke the ends will separate when it warms up and thus, no spark.

1548593667925.png
 

TimBr

Well-Known Member
Hey, @dirter! Welcome to the TreeBuzz forum! I think you are going to like it here!

That was a really great first post! I look forward to reading a lot more from you! Take care, and don't be shy about jumping in on a regular basis. Best wishes.

Tim
 

B_Strange

Member
Here is the procedure for setting the carb on a 261. It's probably very similar to the 290. Of course this is with limiters out of the way.

Every time I've had an engine (not just saws) start and run good cold then bad or not at all when warm it turned out to be the coil. When cold everything is tight. When warm everything expands. If a wire in the coil is broke the ends will separate when it warms up and thus, no spark.

View attachment 57091
Thanks! I’ll give that a shot this weekend. I really appreciate the help
 

B_Strange

Member
Thanks folks! I am working out of town right now but will check the coil when I get back. I really appreciate the help. Thanks!
 
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