New Husky 372xpw mid to low 140's compression

[Oldsawnut]

I stoped by the saw shop in Chehalis today and we did a compression test on a brand new 75cc 372... It was in the mid to low 140's. The techs were just as surprised as I was when I first checked mine out. We did it a few times... A couple diff people on the rope etc.. Highest was 145 or so lowest was 140ish... So I feel better now Might go up 5-10 after 50-100 hrs but I just needed to know. One of the techs couldn't believe it wasnt 170-180 where I thought it should be. My 272 still has over 180 not that its stock anyhow. Anyway just FYI stuff...

John

 

[PES+]

Maybe your hose is too long

ROTF

 

[SawTroll]

It sort of fits with the fact that the power output is about the same, with 4 more cc.

Could it be on purpose, for some EPA related reason?

 

[PES+]

It could be

But then again it could be because it is a cylinder from a cut off saw with a huge combustion chamber that was recycled for use on a chainsaw.

But I still say the shops compression tester hase too long a hose:monkey:

 

[Oldsawnut]

I tested mine was the same... There have been plenty others that have said similar thing in post thats why I wanted to know.. And I know it isn't my tester. Or the guys from the shop. Lets just say its a really experienced tech.

 

[huskydave]

It could be just the squish area is bigger reulting in less compression. I wonder what the stock squish readings people are getting.

 

[SawTroll]

It could be just the squish area is bigger reulting in less compression. I wonder what the stock squish readings people are getting.

That was in my thoughts as well, as they reportedly walks away from the 71cc ones when properly modded.......

 

[Freakingstang]

Walks away? lol

I have seen modded 375's and modded 372's right beside each other. I don't understand why everyone is going gaga over them. It is 4cc and the chop saw cylinder looks to have a bigger combustion chamber...


As for compression, maybe the .038-.048 squish has something to do with it........

 

[SawTroll]

Walks away? lol

I have seen modded 375's and modded 372's right beside each other. I don't understand why everyone is going gaga over them. It is 4cc and the chop saw cylinder looks to have a bigger combustion chamber...


As for compression, maybe the .038-.048 squish has something to do with it........

Yes, the modders have to do away with that high squish number, and I believe Ed does.........:greenchainsaw:

 

[RiverRat2]

Yes, the modders have to do away with that high squish number, and I believe Ed does.........:greenchainsaw:

Its pretty simple to do,,,,, just bringing the squish to .018 -.020 and modding the muffler really wakes them up,,,,,,

 

[Haywire Haywood]

Mine had about 150 cold as it came back from Ed. I haven't measured it lately.

Ian

 

[Andyshine77]

The 372 he built for me has 160 and it's not fully broken in yet, but I doubt the compression will come up much.

 

[scotclayshooter]

Its pretty simple to do,,,,, just bringing the squish to .018 -.020 and modding the muffler really wakes them up,,,,,,

Is that without doing anything to the port timing to bring them back to stock?
Or does the timing benifit from the lowering of the jug?

 

[SawTroll]

Is that without doing anything to the port timing to bring them back to stock?
Or does the timing benifit from the lowering of the jug?

I am pretty sure that port work is needed, but I am no expert.....

 

[Oldsawnut]

I would either have to do it (lowering the squish) with a sander or have someone else do it... Port work everybody does the dremel way..... I think? But the base is a diff story. I know there were 2 diff base gaskets on the 272 you could get that were diff thickness that affected compression.... I wonder if its the same with the 372. I really don't like the idea of no cylinder gasket that a lot of people do. Even if they score both surfaces.

 

[scotclayshooter]

I am pretty sure that port work is needed, but I am no expert.....

LOL You need to change your user name to "StockSawTroll"
Unless you redeem youself with the Lake muffler!!!!!
I bet you dont even own a Dremel!!!! lol

 

[Haywire Haywood]

I rechecked mine a few minutes ago and got just over 160.

Ian

 

[huskystihl]

If no one has said it yet, husqvarna typically has low compression/ 140-150 for the first 25 tanks and then builds to 170-180. My 575 tested 130 and now after a month it is at 160 and getting stronger, that is a good thing.

 

[Andyshine77]

Well Ed did say the compression would come up on my 372, so maybe it will. Now the 7900's are different animals, my stock 7900 has 180, and my ported 7900 has 190.

 

[huskystihl]

You arent kidding, I have a 5100 and my gosh, i'm 34 and I wish this thing had a decomp on it. I feel bad for the 7900 owners that dont't have one it would be like pull starting a sportster.