HUSQVARNA Ported Husqvarna 372xpw

[cdntbone303]

I picked up a Husqvarna 365 for not much to rebuild, it was a little strange looking from the get go with a high top air filter and full wrap handle. Till I took off the top cover and saw 51.4 on the jug. Turned out not to be a 365 but a 365 to ported 372xpw conversion. Looking for a little guidance on what to do with this new piston. The old one piston skirt on the intake side was machined down to increase port timing I am assuming? Do I leave new one as is or take some off the skirt for these 372xpw p/c?

 

[cuinrearview]

If it ate one piston I would be hesitant to throw another(very expensive) one at it without figuring out why. Armed with that knowledge you should be more able to determine if the person doing the work had a plan and knew what they were doing and *s-word just happened, or if they were the latest YouTube porting flavor of the month.

 

[cdntbone303]

If it ate one piston I would be hesitant to throw another(very expensive) one at it without figuring out why. Armed with that knowledge you should be more able to determine if the person doing the work had a plan and knew what they were doing and *s-word just happened, or if they were the latest YouTube porting flavor of the month.

Overheated or straight gased. Muffler was stock

 

[cuinrearview]

Ground on but not MM'd? Seems a little backwards to me. Before messing with the piston I would want to know the timing numbers. It may not even need more intake.

 

[Czed]

View attachment 288122 View attachment 288123 View attachment 288126 I picked up a Husqvarna 365 for not much to rebuild, it was a little strange looking from the get go with a high top air filter and full wrap handle. Till I took off the top cover and saw 51.4 on the jug. Turned out not to be a 365 but a 365 to ported 372xpw conversion. Looking for a little guidance on what to do with this new piston. The old one piston skirt on the intake side was machined down to increase port timing I am assuming? Do I leave new one as is or take some off the skirt for these 372xpw p/c?

If the Piston is useable I didn't read damaged.
Rering it and try it.

 

[huskihl]

FWIW, not much needs done to the intake after machine work on the 372. But if it’s a west coast saw, odds are that they didn’t do machine work anyway. It looks like that piston was adding 20° of intake duration, though. That’s a bunch.

 

[cdntbone303]

Ground on but not MM'd? Seems a little backwards to me. Before messing with the piston I would want to know the timing numbers. It may not even need more intake.

It had a 385 muffler on it. Which now has an extra port for when the saw goes back together. When I go to tdc the piston skirt clears the top of the intake by about 1/8” if I remember right. I don’t have a degree wheel

 

[cdntbone303]

FWIW, not much needs done to the intake after machine work on the 372. But if it’s a west coast saw, odds are that they didn’t do machine work anyway. It looks like that piston was adding 20° of intake duration, though. That’s a bunch.

That’s what I was thinking too. Would think the piston would be out of balance so much was taken off

 

[cdntbone303]

If the Piston is useable I didn't read damaged.
Rering it and try it.

I trashed the old piston, I already have a new one oem on hand. Took me a while to remove the piston transfer from the cylinder, so thought the old piston wasn’t much good anymore

 

[huskihl]

That’s what I was thinking too. Would think the piston would be out of balance so much was taken off

Doesn’t affect balance. I’m just not a fan of shortening a piston. A shorter piston would rock back and forth in the bore more and seems like it would wear out faster

 

[ManiacalMark]

Stock muffler and a shaved piston skirt? Sounds like an old madsens job or a copy of sorts.

 

[cdntbone303]

Stock muffler and a shaved piston skirt? Sounds like an old madsens job or a copy of sorts.

Im thinkin leaving the new piston stock and muffler now has an extra 5/8” exhaust port so should run a bit cooler at least

 

[cdntbone303]

How do find out if the cylinder base has been cut it doesn’t have the stock machining marks that I am used to seeing. It did have a base gasket when I removed the p/c if that means anything. I could also get you guys some timing numbers I picked up a degree wheel but don’t know how to use it yet.

 

[PA Dan]

 

[Sagebrush33]

Kensey of Bayou Country Power Saws also has a nice vid on Youtube of port mapping.
Other good ones are Harvey from IRONHORSE, and Tinman.
I am new to the 2-stroke engines but well versed in 4-strokes. Learning all I can now.

 

[Gord]

Wouldn't 51.4 make it a 375 since a 372 is normally a 50mm?

 

[huskihl]

Wouldn't 51.4 make it a 375 since a 372 is normally a 50mm?

There was awhile when the W meant it had a 51.4 cylinder, wrap, and large dogs. Not sure if there was a time where they called a 375

 

[Stump Shot]

There was awhile when the W meant it had a 51.4 cylinder, wrap, and large dogs. Not sure if there was a time where they called a 375

Was a very short time I believe(?), think @Spike60 even had a sticker that was made.
Bob would be the go to guy for any history on this series of saw.

 

[Stump Shot]

Doesn’t affect balance. I’m just not a fan of shortening a piston. A shorter piston would rock back and forth in the bore more and seems like it would wear out faster

Also not a piston mod fan for just this scenario, cylinder is salvageable and now a custom piston needs made, where it should be just a replace and go again.

 

[huskihl]

Was a very short time I believe(?), think @Spike60 even had a sticker that was made.
Bob would be the go to guy for any history on this series of saw.

I thought I remembered seeing the stickers, but I wasn’t certain