MS 391 piston kit options

[Lightning Performance]

I have a HLS Golf piston wearing Cabers in my MS362 non auto early edition saw. It took specking two pistons to get one that was round. I find this to be the major problem with AM pistons. Less so with OEM types. Short skirts and off size wrist pin sizes seem to be the norm. I used the OE everything but the actual piston. Everything fit very well in an A jug. It was haggard inside from lean seizure so I'm betting now it will be very close to a B jug inside. Ten plus tanks, so far so good. One small note Golf pistons are HEAVY. They can use some weight reduction. Mine is on a diet now. Watch your bare piston weight. The AM wrist pins are always heavier because they are NOT tapered inside the bore. The casting marks should be smoothed out a bit. Mine had no loose casting flashings. Check the clip bore seats they run the gamut of different sizes.

 

[angelo c]

I have a HLS Golf piston wearing Cabers in my MS362 non auto early edition saw. It took specking two pistons to get one that was round. I find this to be the major problem with AM pistons. Less so with OEM types. Short skirts and off size wrist pin sizes seem to be the norm. I used the OE everything but the actual piston. Everything fit very well in an A jug. It was haggard inside from lean seizure so I'm betting now it will be very close to a B jug inside. Ten plus tanks, so far so good. One small note Golf pistons are HEAVY. They can use some weight reduction. Mine is on a diet now. Watch your bare piston weight. The AM wrist pins are always heavier because they are NOT tapered inside the bore. The casting marks should be smoothed out a bit. Mine had no loose casting flashings. Check the clip bore seats they run the gamut of different sizes.

the two OEM 391's that I have done both have had severely squeezed in wrist pins. toughest to remove I've ever dealt with. no ideas why. I had to heat and lube and still beat the snot out of them to get them out.

 

[fordf150]

@angelo c need to check but i should have a piston on the shelf.

 

[fordf150]

back a few months ago bruce @Gentleman asked for some cylinders to get done i sent him a 391 cylinder to have done so maybe he has a update on it

new or old edition 391 cylinder? Stihl has went stupid on the old edition, I assume making the parts so expensive that they get taken out of service early

 

[dall]

it was a non mtronic one i cant remember the year

 

[fordf150]

it was a non mtronic one i cant remember the year

there are 2 cylinders for those, 3 bolt and 4 bolt intake. 4 bolt intake is the OE and jumped in price by $50 or so this year. the OE also has the brake flag bolt being a coarse thread screw that likes to strip out(there is an insert kit for it) and on the later ones they added the metal insert with a machine screw. Not sure of the reasons for changing the cylinder but cylinder, divider, and intake are different. they do interchange though as long as you swap all 3 parts together. If you look at the pictures you can see the difference. https://performanceoutdoorequipment...l-1140-020-1202-11400201202-49mm-cylinder-kit https://performanceoutdoorequipment...l-1140-020-1204-11400201204-49mm-cylinder-kit

 

[dall]

i remember the 3 and 4 bolt intake stuff on the 362 as well i know my 311 has the 3 bolt setup

 

[angelo c]

@angelo c need to check but i should have a piston on the shelf.

Nate,
let me know. I have the three bolt intake one here.
are the pistons different as well ?

@angelo c need to check but i should have a piston on the shelf.

y

 

[Cobby08]

Your dealer is a schmuck
I just checked retail.
$45.49

Yeah... I'd ask another dealer... lol

 

[Adirondackstihl]

eBiz lists different cylinders, but only 1 piston

 

[big t double]

Yup. Two cylinders. One piston. List price about 44 bucks. I'd try a different dealer.

 

[Adirondackstihl]

Yup. Two cylinders. One piston. List price about 44 bucks. I'd try a different dealer.

Bingo!

 

[angelo c]

Bingo!

Nates got me covered....
I figure the AM ones about $30 plus a set of Caber rings and poof....yer at OEM

 

[TJ the Chainsaw Mechanic]

Dealer musta quoted you for a piston and cylinder kit if it was $100. Last I checked the 391 was near the $500+ range. lol Not to mention the early ones were having bearing tolerance issues.

EDIT! Never mind!

1140 030 2008 piston kit is $45.95. Comes with piston, rings, wrist pin, and clips. Plus the fancy box and plastic bags(OH MY!).

The cylinder with piston actually supersedes to a "modified" cylinder and piston. 1140 020 1204 and that costs $242.95.

Not sure where they got $100 from.

 

[angelo c]

Dealer musta quoted you for a piston and cylinder kit if it was $100. Last I checked the 391 was near the $500+ range. lol Not to mention the early ones were having bearing tolerance issues.

EDIT! Never mind!

1140 030 2008 piston kit is $45.95. Comes with piston, rings, wrist pin, and clips. Plus the fancy box and plastic bags(OH MY!).

The cylinder with piston actually supersedes to a "modified" cylinder and piston. 1140 020 1204 and that costs $242.95.

Not sure where they got $100 from.

Im trying to find out from him ....I guess I gave him the wrong PN (1140 030 2003) ?

 

[Adirondackstihl]

So you're going aftermarket?
I'm willing to bet one of the fine dealers here would go at least 10% off retail if not more.
That kinda puts you cheaper than aftermarket.
But if aftermarket is your thing.....go for it.
Ive given up on 90% of the aftermarket parts available. Just not worth it in the long run.

Good luck with the rebuild no matter what direction you go!

 

[fordf150]

Im trying to find out from him ....I guess I gave him the wrong PN (1140 030 2003) ?

that number supercedes to 1140 030 2008

So you're going aftermarket?
I'm willing to bet one of the fine dealers here would go at least 10% off retail if not more.
That kinda puts you cheaper than aftermarket.
But if aftermarket is your thing.....go for it.
Ive given up on 90% of the aftermarket parts available. Just not worth it in the long run.

Good luck with the rebuild no matter what direction you go!

OEM, not sure its 10% off but its a good price shipped

 

[angelo c]

So you're going aftermarket?
I'm willing to bet one of the fine dealers here would go at least 10% off retail if not more.
That kinda puts you cheaper than aftermarket.
But if aftermarket is your thing.....go for it.
Ive given up on 90% of the aftermarket parts available. Just not worth it in the long run.

Good luck with the rebuild no matter what direction you go!

Nope. Nate got me an OEM at the prices above. Won't use AM unless there is a significant savings and a justification ...

 

[sledneck22]

Sorry to resurrect this old thread but I have a ms311 with a 4 bolt intake that is burned up. I would just clean the cylinder but the spark plug hole threads are less than desirable. I'd rather just put a different cylinder on it and be done with it. (I suppose I could helicoil but....rather not have that flaw) However, there's not much out there for 4 bolt cylinders unless I buy new OEM for $250. That's about what these saws go for in my neck of the woods.
Thus, has anyone been successful w/ putting a 311 3 bolt cylinder in a 4 bolt intake chassis? I'm assuming I'd need at least the intake boot as well but with all that I'm only looking at around $80 compared to $250.
Thanks.

 

[Fifelaker]

Turn it into a 390.