Stihl MS250 bogs under constant throttle

[Rockjock]

Sorry, but not by my definition of "great". C'mon. The name is the selling point.

Well your definition may need a little revision. I am not saying it is a pro saw replacement but as many have said the 025/MS250 have cut many many cords of wood. For what it is indented for it does a great job. A simple muffler mod and retune and it does very well for itself.

OR you can do this.......

 

[Wood Doctor]

One other possibility, assuming it's a new carb. There could be a hairline crack in the fuel line that leads from the tank to the carb. That happened to me once before. The engine will run, but it runs erratically.

I kind of like the 025 or 250. It tends to run like a souped up 021 with not much additional weight. However, compared to an 026 Pro, it's kind of a dog.

 

[Den69RS96]

Well I found my problem and I feel stupid for ignoring the obvious. When the dealer gave me the carb he included the gasket on the right. The original gasket is on the left. The impulse hose for this saw does not connect directly to the carb but to the back of the housing the carb attaches too. There is a hole in the housing and intake boot which aligns to a hole on the carb for the impulse. In the second photo you can see the hole for the impulse line. The new gasket blocked the hole which explains the bogging. At least I know my saw is still in excellent condition lol.

 

[KG441c]

Did u run it yet?

 

[Den69RS96]

Yeah. It ran awesome. Made about 10 cuts into a old 6 inch oak branch and it when through it with very little effort.

I know folks knock these saws because they are a clam shell design, but I love this saw for what I use it for. Its wicked light and has decent power which makes it a great saw for limbing. The only thing I'm not a big fan of is the antivibe system which is why I use my 361 for most cutting and I'll break out the 046 if I need too. The pro saws are definitely easier to take apart, but my 250 wasn't to hard to take apart.

 

[Wood Doctor]

That carb gasket is a must for this saw to run right. Many catbs sold for the 250 or 025 do not come with one and get bolted on without the gasket at all. A few years back I made my own gasket using shirt board and that worked for several years. Some guys have used the cardboard that wraps up soft drinks or beer cases. Best bet is to have the dealer order you one like the original you showed in post #43.

A good little firewood saw, I predict you will cut lots of wood with it.

 

[Slee050409]

What you describe is fairly standard MS250 performance

That's only standard if you allow it to be for your saw. I've had one for several years. Old and new generation 250. It's one of my favorite saws to use actually. Continuously running poor running equipment will only promote further issues.

 

[Wood Doctor]

I'm actually glad this old thread got posted again. I ran into a vintage 021 today and the owner said it ran sporadically and would shut off when warm. Turns out that someone forgot to tighten the carb mounting nuts enough to make good contact with the gasket. Saw was also filthy all over. I cleaned up the carb, the rest of the saw all over the place, and mounted it back up correctly.

Still had good compression, it started on the third pull and runs correctly. Not bad at all for a 25 year old, and I bet it weighs a quarter pound less with all the gunk and grime I removed. Before I started, it looked something like this 025 that I worked on two years ago: