Funny story & MS231 compatibility with MS241??

[CJB78]

OK so New to the site .

So G'day from The Pilbara.

I cooked My MS231 pretty much straight out of the box and Stihl wouldn't cover warranty.
Excuse: The scoring on the exhaust side of the piston was from running to lean. Well once I stripped it down the scoring was pretty much evenly distributed around the piston.
Meh what do you do....
So I think might as well have a crack at rebuilding it. Rang Stihl and got a price for the rebuild kit and OEM Part No.'s (may as well buy a new saw LOL ).
May as well have a crack at doing it on the ole Ebay cheap..
Clean the cylinder up, comes up a treat, ordered an ebay Piston the equivalent to OEM #1143 030 2005 (41.5 mm Piston), Part rocks up in two weeks (unbelievable for here normally 4-6 weeks for anything to get here).
Being as excited as a fat kid in a candy store, I throw the new Piston and rings in, Slides in like a dream.
Quick re build pull, pull, pull Gee not much compression (Note: I had cleaned up the old piston and tested compression with one Piston ring was pretty good).
Bloody hell I say to myself..
Pull the cylinder and piston out check for scoring on the new Piston.
Nothing????
Whats this, why can I see part of the end of a piston ring. Hmm made in China, rings must be under size.
Lots of head scratching...
Hmm piston port on the new one looks a bit smaller on the new one.
So after much faffing about I decide i should measure it like the good Fitter and turner I am.
What do ya know the old one is 42.5mm That cant be I say to myself The Stihl shop said its 41.5mm.
Turns out the Changed it around 2013, the new OEM # 1143 030 2013 is what i needed LOL.

So You've go this far.

My question: Is the OEM # 1143 030 2004 42.5mm piston from the MS241 be the same as the new MS231 Piston OEM # 1143 030 2013?

Atpchas/ Charlie has been a legend in parts list assistance.

The only drama is they don't list the new MS231 piston and ring part No.

If I can just find some info to go along with my thoughts of fitting the Piston from the MS241 into the MS231.
They both appear to have the same profile and Porting on the piston.

Thanks for sticking it out thus far. Hope it makes sense.

Grateful for any assistance

Cheers

Chris..

 

[Franny K]

Sorry I can't help with all the stihl part numbers. The 231 is essentially a small bore 251 isn't it? They share the same owners (and service) manual. I do not appear to have found a parts list to save in searches. Guys buy new saws and take them apart and sell the pieces new/unused on ebay. I would have searched for an engine module off ebay as a first option.

 

[DND 9000]

The piston of the MS 241 and the piston of the MS 231 (new version) have the same diameter (42,5mm) but they are not the same, they have different part numbers.

 

[Conquistador3]

I have a 231 as well and I've already asked the question.
The answer is the only things the 231 and the 241 share are are several fasteners and bar and chain (for the latest, 3/8" equipped 231's).

 

[CJB78]

So its not just a case of changing the part No. To charge more?
Just surprised that the Gudgeon pin, needle roller and Piston rings (bit of research both rings are 42.5 x 1.2 mm) are compatible.
Wouldn't be the first time a company changed the Part No. And ask for a premium price.

 

[Adam08ski]

Just encountered the same problem. Can't find a suitable replacement for this 42.5mm. Nowhere here in the UK does them. But looking at the 241 piston. Looks very similar apart from the intake notch around the piston skirt. Ports look similar.. I'm getting frustrated lately with these mid product cycle changes on saws. I now have numerous spare pistons for saws that I don't have..

 

[HarleyT]

The ms231 and ms251 are the same saw, except for the piston/cyl. size

 

[Adam08ski]

The ms231 and ms251 are the same saw, except for the piston/cyl. size

Yep know this. But the MS231 changed bore size from 41.5mm to 42.5mm in 2013 and nowhere here sells the 42.5mm. Secondly can't find a MS251 cylinder else I would have just got one of these. The cylinder I have is OEM and good condition. Previous owner mullered piston using a screwdriver as a piston stop else I would have just got a set of 42.5 rings and be done with it.. I just need a 42.5mm piston and rings and I'll be happy (laughing to myself at how hard this is being)

 

[harpersend]

I believe Meteor has the 42.5mm piston for the MS231... Not sure on availability though...

 

[HarleyT]

Put up the part number of the piston assy that you need. I don't see any references here right off.

 

[HarleyT]

Found it. #1143 030 2013
In partsmart with no price, so I guess not available in the US

 

[Adam08ski]

Sorry yeah that's the one. Only one I can find is in Romania and is what I am guessing $80 ish. Think this is a shelf it till a used one arrives on eBay or sell it for as someone else's problem.

 

[Adam08ski]

So it's official for any of you who want to stick a MS241 piston in your difficult to find MS231 42.5mm. YOU CAN ... if you are willing to get a dremel on those little strato ports on the side of the piston. All wrist pin to piston top, piston skirt and shapes are the same. Just the ports needed lengthening. My ms231 is now running. Job done...

 

[Adam08ski]

These are the areas that I attacked with a dremel. Works a treat. Quick fix for the rare ms231 42.5mm using a 42.5mm ms241