How to run a 12mm piston on a 10mm pin crank (w/ photos)

[francisjohn]

Sorry, I just don't like bushings even if they aren't the main bearing.

Fair enough, do you have a link to this MS380 or MS038 10mm piston? I was under the impression they are only 12mm but I cannot see to find a 10mm anywhere. I'm really curious to see it because it can be used in other applications if this is the case.

 

[GW's Motorized]

Fair enough, do you have a link to this MS380 or MS038 10mm piston? I was under the impression they are only 12mm but I cannot see to find a 10mm anywhere. I'm really curious to see it because it can be used in other applications if this is the case.

Oops, I meant the earlier ms440 magnums. They had a 10mm pin, not.the 380. I've just got so many numbers of 52mm bore chainsaw engines jumping around in my head. I am having trouble finding a replacement for one with a 10mm pin however because it was all earlier models.

 

[francisjohn]

Oops, I meant the earlier ms440 magnums. They had a 10mm pin, not.the 380. I've just got so many numbers of 52mm bore chainsaw engines jumping around in my head. I am having trouble finding a replacement for one with a 10mm pin however because it was all earlier models.

Ah no worries, I was super intrigued as the list of possibilities came into my head. Replacement 10mm pin piston, for which bore? I might be able to point you in the right direction

 

[GW's Motorized]

Ah no worries, I was super intrigued as the list of possibilities came into my head. Replacement 10mm pin piston, for which bore? I might be able to point you in the right direction

It was the earlier ms440 magnum. I was looking for the ms380 when I found a site that had a piston listed for an ms440 magnum and that's what reminded me.it was the 440 magnum.

 

[francisjohn]

It was the earlier ms440 magnum. I was looking for the ms380 when I found a site that had a piston listed for an ms440 magnum and that's what reminded me.it was the 440 magnum.

This one? or 52mm?

Piston kit for Stihl 044 MS440 50mm, 10mm pin replaces 1128 030 2000, Bearing | eBay

<p>Piston kit for Stihl 044 MS440 50mm, 10mm pin replaces 1128 030 2000, with Bearing. </p>

www.ebay.com

 

[GW's Motorized]

This one? or 52mm?

Piston kit for Stihl 044 MS440 50mm, 10mm pin replaces 1128 030 2000, Bearing | eBay

<p>Piston kit for Stihl 044 MS440 50mm, 10mm pin replaces 1128 030 2000, with Bearing. </p>

www.ebay.com

Maybe it was 50mm.

 

[michael whiteman]

I noticed the oil hole in the con rod and felt that a countersink bit would make a really nice chamfer on it.
It's a common practice on high performance automotive engines.

Also, has anyone stripped the cages off the rollers and just used more of them filling the space up entirely?

 

[Chainlube]

Sorry, typo,

372 = 50mm
372XP = 52mm

I don't understand your post at all. Was your only intent to make a correction because you have nothing else to contribute? If I wouldn't of ever wrote about a 372XP would you of even commented at all?

My point is, Husqvarna doesn't make a 372XP with a 52mm bore, check the link provided. Of course if you bought an aftermarket cylinder and piston you could very easily have a 52mm jug and piston, but not made by Husky but labeled a 372XP. We run all Huskies in the bush here, it's a very common saw.

 

[francisjohn]

I noticed the oil hole in the con rod and felt that a countersink bit would make a really nice chamfer on it.
It's a common practice on high performance automotive engines.

Also, has anyone stripped the cages off the rollers and just used more of them filling the space up entirely?

I am confused and do not understand what you're saying.

 

[francisjohn]

My point is, Husqvarna doesn't make a 372XP with a 52mm bore, check the link provided. Of course if you bought an aftermarket cylinder and piston you could very easily have a 52mm jug and piston, but not made by Husky but labeled a 372XP. We run all Huskies in the bush here, it's a very common saw.

You're right. That's my fault.

They do not make a 372XP 52mm. They are aftermarket top end kits. This is also my fault for not doing my due diligence.

Up until a week ago, I was under the impression that there was a 372XP 50mm and 372XP 52mm. I was recently aware that these big bore kits aren't OEM (such as you can't buy a 52mm 372XP Husq off the shelf) I contacted someone about my 372XP build and he corrected me and said 372 is a 50mm, and the XP is 52mm. Now me trusting the guy I said hmm, that makes sense? Weird I haven't found this straight forward difference. It appears I was right originally, believed someone else and didn't bother checking, and here we are today