Small Engine Tech and Classifieds

[JTU]

Need a little assistance from the small engine gurus.

MS250 Stihl saw, about 6 years old or so. Has always fired up in a few pulls. No start.

View attachment 1754702

I got a "tune-up" kit and replaced the plug, air filter and in-tank fuel filter. Still no start. When I go to start it after a few pulls I smell fuel. When the plug is removed there is fuel in the cylinder and on the plug, seems like it isnt getting fire. Also, fresh fuel in the tank.

I'm gonna google on it, but thought i'd throw it up here to see if any of you could offer some additional tips. @MScruiser @BOSS man @D'Animal

Thanks in advance

Ironic you posted this just a few days ago. Went to crank my MS250 today and no starty. Same symptoms as you describe. Did you get it running?

 

[MScruiser]

Try some starter fluid. Sometime getting it cranked up briefly, can unclog whatever’s in your jets.

 

[jynx]

Ironic you posted this just a few days ago. Went to crank my MS250 today and no starty. Same symptoms as you describe. Did you get it running?

I have not. Haven't had a chance to dig any deeper into it. May try the above to see if that helps.

 

[JTU]

@jynx this may be helpful to you. Turns out it was just really flooded. Pulled the plug out and turned the saw upside down and pulled the cord 15-20 times. A good bit of gas came out. Dried the plug off and put it back in and the saw started right up.

 

[MScruiser]

The better question was why was it flooded when you went to crank it? If it is filling up with gas while not in use, you’ve got a stuck metering valve.

 

[Clutchee]

MScruiser- I’ve got two Honda generators.... with idle issue.

Both will start and run but seem to lope or idle up down, up down, is that sign of carb issue or possibly something else?

Like to know your thoughts.

I’ve tried last couple days to run fuel cleaner through them and let them run for hours but no changes in idle.

 

[MScruiser]

Yes, sounds like a dirty jet. Cleaners only work some of the time. Sounds like you need to clean the carb. Make sure you don’t have water in your gas first though; that’ll do it sometimes.

 

[Clutchee]

Yes, sounds like a dirty jet. Cleaners only work some of the time. Sounds like you need to clean the carb. Make sure you don’t have water in your gas first though; that’ll do it sometimes.

Thanks...
what’s required to do that?
I’m on 100 level classes for this...

Carb kit? Rebuilt kit?

Just take off and clean?

 

[subzali]

What do you use to clean jets? Fine picture wire? I have a Stihl trimmer I pulled out of a neighbors trash he said should run but he couldn’t get it to start. Wouldn’t circulate fuel but finally got it to do that and it has spark but still no start so I think the jet is plugged. It will run momentarily on starting fluid.

 

[MScruiser]

Just replace carb. Too much trouble trying to rebuild.

 

[jynx]

Picked up a new project today. Stihl 031AV. Don't know what that means, but I aim to find out.

My dad has had this saw for as long as I can remember. It started giving him trouble when I was younger and is one of the only memories of my father being so angry he threw something.

He got a new saw several years ago, and while home for Thanksgiving today I saw his new saw in the shed and asked about his old one. He said it is out in the shed under the old table saw. I dug it out. Plug has been out for a while and it seems seized, so we sprayed some pb blaster in it. I will fill it up with marvel mystery when I get home and see if I can get it to spin over. Going to have to do some reading and will have to hit up @D'Animal for some pointers and tips for the rebuild.

 

[MScruiser]

The first order of business, will be converting it from points to a more modern ignition. Go on YouTube and look it up. That’s probably one of the reasons it was giving your dad trouble in the first place. I would go ahead and order a new fuel and oil lines, along with filters, and probably might as well get a new air filter, and also assume you were going to have to get into the carburetor. Otherwise, that is a good soul. My father-in-law has one. Parts are a little on the hard side to find.