Stihl Ms250 Won’t Run

[Bear1088]

I rebuild stihl chainsaws all the time, so I am not new to this. Latest one is a ms250. Big this was, crank was worn where bearings sit. Called stihl and the said that the 025, which I have a parts saw, is the exact same crank. So I swapped over piston. New parts, bearings, seals, all new lines, carb, air filter, plugs and a few minor things as well. All back together and it will not fire, not even on starter fluid. Now I double checked things. Crank is identical to one removed. Coil is adjusted properly and I have great spark, great compression, fuel is through carb and into motor, new gas, no carbon build up on exhaust side or in exhaust, flywheel key is NOT stripped off. I have checked that where piston is on stroke n when spark will fire, that coil and flywheel is all lined up. Now I am a bit baffled.. figured I would check to see if I have any other coils for this saw and try them, even though the one I have is working and I have good spark. Does anyone have any ideas or thoughts?

 

[medalist]

I'm thinking it would need to be way out of time for it not to fire. Maybe compare the old flywheel to the ms250 and check magnet/key alignments.
Just guessing of course.
I've heard many users complain at the ability to easily flood on start but assumed you are principal user/owner and you are way past this issue.
Good luck.

 

[cookies]

i have suffered a terrible no start i found to be a failed new spark plug and the used plug was bad too, both would give a blue arc when tested out of the saw....had a coil spark through its case once too that had good spark when tested..figured that one out at night LOL

 

[Tigwelder83]

I had one that was super temperamental. If you didn't catch it just right it would flood. Had it at 3 different saw shops, finally an Amish shop fixed it right... I traded it for a jonsred 2165, and smiled.

 

[sundance]

I had one that was super temperamental. If you didn't catch it just right it would flood. Had it at 3 different saw shops, finally an Amish shop fixed it right... I traded it for a jonsred 2165, and smiled.

Wish I could find a shop that could address mine. Any idea what the Amish shop did? Where was the shop located? I suspect a long ways from me southeast of Pittsburgh.

 

[Tigwelder83]

Wish I could find a shop that could address mine. Any idea what the Amish shop did? Where was the shop located? I suspect a long ways from me southeast of Pittsburgh.

I dunno what he did, I left with a different saw...

 

[dirty]

Check your impulse line connection under your rear handle body housing.

 

[medalist]

Wish I could find a shop that could address mine. Any idea what the Amish shop did? Where was the shop located? I suspect a long ways from me southeast of Pittsburgh.

Not being intimately familiar with the MS250 I see in parts they use the choke flap built into the carb.
I'd either put a small bend in the linkage to reduce some throw or drill a hole in the choke flap to give it some air.
Good luck.