MS440 Magnum Low Compression?

[flhx]

Newbie checking in here; I just received a Stihl MS440 Magnum from a friend. It's a non runner. The first thing I checked was spark (good) and compression (90 PSI) I removed the exhaust and the piston does not appear to be scored, the rings don't appear to be in to bad of shape. I'm thinking of just replacing the rings.

My understanding is anything under 110 PSI is unacceptable.

* Any and all technical assistance will be greatly appreciated.

Thank you all in advance

 

[Redfin]

Is your decomp seating?

 

[huskihl]

Pull the cylinder and check it and the piston out for scoring. If they're both fine, remove the rings and slide one up into the bore, use the piston to square it up, and check the end gap. Ideal is .010"ish. Yours is hopefully. 050". If there's no aluminum transfer, and the piston skirts aren't worn, a new set of oem or caber rings will probably get it going like new again.

Feel free to post pics as you progress

 

[huskihl]

Is your decomp seating?

Or that, lol

 

[flhx]

Is your decomp seating?

Yes the decomp does appear to be seating. After a closer examination (Much more light) there is some scoring on the piston and rings. I can get a finger nail into the scoring. The cylinder appears to be in good shape.

Is there a site you could recommend for OEM parts? Or parts that are worthy of installing onto a Stihl?

Thank you for the rapid reply.

 

[flhx]

Pull the cylinder and check it and the piston out for scoring. If they're both fine, remove the rings and slide one up into the bore, use the piston to square it up, and check the end gap. Ideal is .010"ish. Yours is hopefully. 050". If there's no aluminum transfer, and the piston skirts aren't worn, a new set of oem or caber rings will probably get it going like new again.

Feel free to post pics as you progress

Your technical assistance is greatly appreciated. Thank you. I'll keep you posted. I'll share some pictures along the way.

I'm in need of a reputable site to purchase OEM or OEM spec parts from, any suggestions? You get what you pay for.

Thanks again

 

[Dub11]

Your technical assistance is greatly appreciated. Thank you. I'll keep you posted. I'll share some pictures along the way.

I'm in need of a reputable site to purchase OEM or OEM spec parts from, any suggestions? You get what you pay for.

Thanks again

HL Supply with a Meteor or CCC

 

[flhx]

HL Supply with a Meteor or CCC

I'll check them out. I understand what Meteor is whats CCC? Caber rings?

Thank you

 

[RI Chevy]

PM sent to you.


Sent from my SM-G930V using Tapatalk

 

[Dub11]

I'll check them out. I understand what Meteor is whats CCC? Caber rings?

Thank you

Chainsaw Conservation Components ran by an awsome site member it has oem and am parts.

 

[flhx]

Chainsaw Conservation Components ran by an awsome site member it has oem and am parts.

Every day's a training day. Greatly appreciated

 

[huskihl]

The aluminum will most likely clean off the cylinder walls either with muriatic acid or by sanding. There are how-to videos on here. Meteor piston comes with cabers. @Definitive Dave owns CCC and has an eBay Store that will have what you need.

 

[flhx]

Dammit Man, you guys are $hit hot. What a great resource, thank you