Stihl MS250 Conversion to Easy Start

[Bosco Beaver]

Has anyone been successful in converting a Stihl MS250 to the MS250C Easy Start? Don't need the automatic chain tensioning feature, just wanting to make the saw easier to pull/start since and old shoulder injury is taking its toll on me. An authorized Stihl dealer's repair shop made this conversion for me and replaced several components but now the Easy Start mechanism has failed and he is telling me he shouldn't have made the conversion in the first place. Just need to know if anyone has done this and what parts (and part numbers) they used. Thinking the crankcase might be different on the two models and thus causing the problem with the repeated failure of the easy starting mechanism, since it appears there is a "decompression valve" in the easy start version but not in the standard version. Any help would be greatly appreciated. Also, I found, and have attached a tech bulletin from Stihl concerning the Easy Start, and it appears some versions (series) of the MS250 are not compatible with the Easy Start feature. I've attached this tech bulletin in the hope someone much more knowlegable than myself can interpret this and explain if my saw can be converted.

 

[irhunter]

The doc you posted says early MS250 won't take easy start and:

"Due to the geometrical changes, engine housing
1123 020 3027 is installed in the MS 250 C with
Easy2Start"

I assume if you don't have the specified case, your saw is too old.

I find it unfortunate that a dealer may be trying to install parts onto an incompatible saw. If that ends up being what's going on, I would find a different dealer.

As you probably know, lots of people report their 250's are hard to roll over. You might need to replace the original parts, sell the saw, buy something easier to start.

Roy

 

[ballisticdoughnut]

I installed an elastostart on my MS250. Definitely made a difference it’s more comfortable to start but if you’ve got a shoulder injury it’s not the saw for you.

 

[82F100SWB]

From what I remember, the easy 2 start saws run a different ignition coil which has a different advance curve, that also has a different mounting pattern, hence the different engine case. It's been a while and I can't remember all the details, but that could be your issue.

 

[sonny580]

I too was told that they are a TOTALLY different animal! I now run 2 of the 250's and the first one was a bear til I replaced the original carb with a different chimna knockoff carb that had open set screws without stupid caps on them. --- Made a new saw out of it! The original carb was Zama, BUT also made in china so I stuck another one on it.--original one was defective from the factory. Sthil's are strange about starting anyway and if any little thing is off a hair they are really hard to start.
I would suggest that you sell the 250 and get a Echo 310 for easy starting. Sthil 009 that I have is a decent starter too, so test other models/brands and see what you come up with.

 

[a. palmer jr.]

Has anyone been successful in converting a Stihl MS250 to the MS250C Easy Start? Don't need the automatic chain tensioning feature, just wanting to make the saw easier to pull/start since and old shoulder injury is taking its toll on me. An authorized Stihl dealer's repair shop made this conversion for me and replaced several components but now the Easy Start mechanism has failed and he is telling me he shouldn't have made the conversion in the first place. Just need to know if anyone has done this and what parts (and part numbers) they used. Thinking the crankcase might be different on the two models and thus causing the problem with the repeated failure of the easy starting mechanism, since it appears there is a "decompression valve" in the easy start version but not in the standard version. Any help would be greatly appreciated. Also, I found, and have attached a tech bulletin from Stihl concerning the Easy Start, and it appears some versions (series) of the MS250 are not compatible with the Easy Start feature. I've attached this tech bulletin in the hope someone much more knowlegable than myself can interpret this and explain if my saw can be converted.

I've done a few conversions but the owners want them converted away from Easy Start to the conventional starter system. It should be an easy, bolt on operation but I don't remember if the flywheel needs changed also or just the starter assy. Since the starter sticks out more than the conventional one you might have to change the front handle bar to a 250C bar, not real sure about that because I've only changed them the other way.

 

[user 74409]

I am a fan of the MS250/MS250C saws and have successfully disassembled and reassembled many without having extra parts when finished.

To convert MS250 to MS250C, saw will need to be completely disassembled and parts that need to be changed are recoil, flywheel, ignition coil, case, bar stud, chain tensioner and MS250C black wrap handle is wider.

A more cost effective approach might be to start with blown up MS210C with EZ 2 Start recoil. Swap 45cc MS250 engine for blown up 35cc engine, install metal heat shield used on MS230 & MS250 (between engine & muffler) and install MS250 carburetor. At this stage you would have 45cc MS250 with EZ 2 Start with tool-less chain tension system. To go to standard clutch cover, you need to add second bar stud, chain tensioner, two bar nuts and swap to standard clutch cover.

I did the MS210C engine upgrade to 45cc when I wanted a saw to use as a test mule to try out Hyway cylinder and Meteor piston combination. I left the tool-less chain tension system in place without changing to standard 2 bar stud version.

The stock MS230C and MS250C came with a primer/purge bulb with different orange housing handle, different vent hose routing and a Zama C1Q-S92 carburetor with extra outlet for primer. Primer does reduce number of pulls needed to start.

 

[a. palmer jr.]

I just ordered the parts to change a Stihl MS251 from easy start to conventional. It definitely needed a flywheel for the conversion. I didn't change the clutch side because customer didn't indicate he wanted it changed. If it were mine I'd change both sides..

 

[mrpackrat]

Just my 3cents worth here. About those Stihl option letter meanings, Stihl says
B: Quick chain adjuster, a tool-less chain adjustment.
C: Comfort, for ergonomic and lightweight designs.
E: Easy2Start, making this Stihl Chainsaw easy to start up. It can have C by itself. If it has any other option then it will always have the C option first.
About the C option in MS250C, not sure what it has to have to qualify for a C to mean Comfort, maybe the factory workers blessed it before it went out the door. The letters will not be on the top cover nor the side cover decal label on saws ive seen. But they are on sales tag and on the owmers manuals.
I have an 017, 018, 025 and a MS250 , all with toolless chain adjuster and regular pull starter. So their models would be 017C-E, 018C-E and MS250C-E. Also i have an MS250 with the easy pull starter and regular 2 nut clutch cover. So I guess this would be an MS250C-B.
About conversions, this MS250C-B came from a yard sale and the easystart was not working, it would sometimes grab and start the saw and sometimes slip. My local dealer said they do that when people pull the ropes out too far and damage the plastic piece inside or brake the easy start spring. I chose to swap out the starter cover assembly with one from an old 025 on the back shelf that i got for 5bucks somewhere. Well that old 025 starter cover would not fit in the flywhell on the MS250C-E.. Those two flywheels are a little different in the center where the starting pawls are. So i swapped the flywheel too and the easy start cover fit and worked just fine for the last 8 years or so. But it does have the front handle bar out alot further than it should be and looks funny.
I just got an 025 in a truck load of parts yesterday, it has the starter cover cracked and has high compression for sure. The guy said his buddy had sent it off and got it souped up and modified for more horsey powers, and he kept breaking starter ropes from its higher compression. The guy who modified it rebuilds aircraft engines and used something called a bridge port machine on the saw. So, in next few days im gonna see if i can put the MS250c-E flywheel and starter cover on it. If it will fit ok them im gonna get the parts and fix it.

 

[a. palmer jr.]

The last 251 I converted from easy start to conventional didn't work well for the owner so he wanted it changed back to easy start. If he had learned to properly use the easy start it would have saved us a lot of trouble..

 

[Treeman2021]

Same thing i was told when i asked about the easy start for my 211 it surly needs something, maybe a De-Com.p would have been a good idea.

But making into an east start was a no deal.

 

[a. palmer jr.]

Same thing i was told when i asked about the easy start for my 211 it surly needs something, maybe a De-Com.p would have been a good idea.

But making into an east start was a no deal.

On at least on Husqvarna model they had an automatic de-comp on it, you never had to push the button for it to function, just pull the rope. I think I saw it on a 357xp.

 

[cgunz410]

Has anyone been successful in converting a Stihl MS250 to the MS250C Easy Start? Don't need the automatic chain tensioning feature, just wanting to make the saw easier to pull/start since and old shoulder injury is taking its toll on me. An authorized Stihl dealer's repair shop made this conversion for me and replaced several components but now the Easy Start mechanism has failed and he is telling me he shouldn't have made the conversion in the first place. Just need to know if anyone has done this and what parts (and part numbers) they used. Thinking the crankcase might be different on the two models and thus causing the problem with the repeated failure of the easy starting mechanism, since it appears there is a "decompression valve" in the easy start version but not in the standard version. Any help would be greatly appreciated. Also, I found, and have attached a tech bulletin from Stihl concerning the Easy Start, and it appears some versions (series) of the MS250 are not compatible with the Easy Start feature. I've attached this tech bulletin in the hope someone much more knowlegable than myself can interpret this and explain if my saw can be converted.

I just installed an Easy2start flywheel and starter on an MS250. Starts right up.

The only thing that won't swap over is the MS250C ignition module. That's where the cases seem to differ.

I still need to swap a MS250C handlebar to get a little more clearance at the starter so I can fit my fingers in there better.

 

[thompsoncustom]

Same thing i was told when i asked about the easy start for my 211 it surly needs something, maybe a De-Com.p would have been a good idea.

But making into an east start was a no deal.

I would thinking adding a decomp would be the easier and cheaper option.

 

[sonny580]

cant put decomp on these little saws can you??? If so , that would make the 250's easy to start! lol!

 

[cgunz410]

cant put decomp on these little saws can you??? If so , that would make the 250's easy to start! lol!

There are ways to do it like old big 2 stroke bikes and sleds. Take the cylinder apart, grind a little dimple in the roof of the exhaust port, however far away from the bore you like and drill a tiiiny hole from there to about 1/4" above the exhaust port in the bore, right through the plating and then chamfer that.

Another way is a vertical finger groove from the top of the transfer, to above level with the exhaust port roof.

 

[thompsoncustom]

cant put decomp on these little saws can you??? If so , that would make the 250's easy to start! lol!

You can put a decomp in any saw cylinder it's just a hole with some threads.

 

[cgunz410]

You can put a decomp in any saw cylinder it's just a hole with some threads.

Exactly this, just need to place it somewhere it can be pushed with your finger, or if the outer plastic casing is in the way, drill a hole in that.

 

[a. palmer jr.]

I've changed them both ways, to Easy Start and from Easy Start to conventional. Just need the starter assembly, flywheel, and handlebar. I usually don't mess with the ignition. Learning how to use the Easy Start is most people's problem.