Stihl 021-025/MS210-MS250 Muffler Mod

Only 025 I ever had was fixed jet H needle. Boo!

 

Boo is right lol !

 

Is your tank pressurized? When you open the tank when it refuses to start is there a rush of air? Is your L needle adjusted right? Will it start if you put it on half choke?

 

When it happens, I try everything to get it going again. Short of pulling out tools & checking the plug etc.. No luck. But if I let it sit there for a half hour, it will usually fire right up. Has me really stymied - it works great the rest of the time, jetting seems good. Cold starts seem normal - 2 or 3 pulls in the cold position give me a pop, then one click up & go on the next one. It doesn't happen often, but when it does it about drives me. I really like the saw, except for that.

 

When you go to re-start it warm, are you choking it? High idle starting it? Or just flip to run and pull?

 

Will it do it if you run out of fuel and refill as well as just you shutting saw off to move a log and say go to restart it?

 

Moved to my tablet. On the couch. So typing will be short. Doesn't do it when I run out of gas. Yes, usually when I stop to move stuff - have taken to just letting it idle for those few or 10 minutes. I start out cranking my way down thru the trigger settings, few pulls at a time, starting at simple idle and ending in the full choke & throttle position & frustration. No pressure in the tank, pretty sure. I don't cut in winter, so it's out of mind for a few months. Its usually the first saw I go to, which makes it that much more aggravating. I do plan on putting a new plug in it when cutting time comes again, has new air filter.

 

That model can flood real easy.. Next time you shut it off warm, and go to restart, hold the throttle wide open and drop start it.
See if it fires off and goes 1 pull. No choke, just grip and rip...

 

Yea when it won't start drop starting trigger wide open it should fire even flooded after 6 pulls or so.

Its a small saw so it should be fairly easy. Not like drop starting a 660 with 25" bar

 

Pretty sure I've tried the drop start wide open no choke thing too. That was usually before I hit the choke in last-try desperation. I will see what spring brings & how it goes then - thought there might be a trick to a common 250 problem I hadn't heard about. Thanks for the feedback!

 

Cool thread. I've had an MS250 for about 5 years now; great saw. It starts reliably and has always run well.

Good point about tuning the carb after a muffler mod. I'm convinced just about anything with a carb these days is tuned lean from the factory due to emissions. Once you start getting more airflow through the engine, it just exacerbates the issue.

 

Theres that video again

May as well throw the tuneing one up for good measure as well. Seriously its a good one that walks you through it.

 

New too this site but been around for awhile. Hello all. What would happen if you removed the baffle?

 

Free up restriction in the muffler and make it louder. And make the saw faster..assuming you open up the outer exhaust hole as well.

And welcome too.

 

For those interested in muff modding a 180/018 a walboro wt-215 is fully adjustable and fits with minor mods. I believe there is a thread about it on Another Site. I have not done one yet but have one here I will get to after syrup season.

 

Thanx for the welcome and info. I have an 021 and took it apart too open it up and the baffle fell out so I left it out. Just wanted to make sure it would be OK to leave it out. I tuned the carb and it is louder but runs much better. Was worried about back pressure leaving the baffle out but sounds like it's ok. Thanx again