how to tell apart 371XP vs 372XP vs 365 Special

[Karl2020]

Hi folks,

I'm fairly new to the site and pretty excited to post my first ever question. First of all, I'd like to point out how useful this site is and really appreciate the knowledge base around here. I'm just an amateur do-it-yourselfer from Thunder Bay, ON where pulp and paper and forestry used to be the main industry. I don't cut professionally nor am i mechanic, but i tinker in all sorts of things- saws being the latest.

Anyway, I'm fixing up what looks like a mid 90's Husky saw my step dad gave me to tinker with and hopefully get back up and running. I thought he was giving me his old 372XP to work on which stopped running 2 summers ago. What he gave me instead was some pro saw with a 365 Special decal on the recoil. I suspect the saw is actually a 371 XP since it looks suspiciously like my own 371 XP (orange head cover clips, Walboro carb, one piston ring). The saw he gave me has been through the gears and back to say the least...It's missing the little black model # ID plate usually found on the oil tank. Like a lot of bush guys around here, he's a whiz on a saw but doesn't care much for maintaining it...So he's not even sure himself which saw he gave me. Anyone know how i can tell for sure which saw i have without the black model # decal?

In summary: I thought i was getting a 372XP which I know he did own at one time (seen it with my own eyes). But what i got instead was a saw with a 365 Special recoil but appears to be the inner workings of a 371XP.

Thanks!

-Karl

 

[Woodslasher]

Check the cylinder bore, 50mm is 372, 48mm (I think) is 365 .

 

[Karl2020]

Check the cylinder bore, 50mm is 372, 48mm (I think) is 365 .

Oh yeah! Ok that makes total sense to tell apart a 365 from 372/371. Thanks for that suggestion. I'll check tonight to rule out whether it's a 365 or not.

Now that just leaves me wondering if it's a 371 or a 372. Like i said, it's got orange cover clips and a single piston ring. To me that sounds like a 371. Was there ever a model year where Husqvarna called that a 372? I'm just confused as all hell because i swore he used to have a 372 with gray clips. Sounds like the old man is pulling a fast one on me here and i'll never know for sure. Could be he has all 3 saws and mixed/matched parts from all 3.

 

[Westboastfaller]

Likely a 371 of 365
Clutch drum my have holes in it for a early 371 some had a three point mount on the inside dog. Yes the top is a 371 with orange snaps.front of the top cover I believe is different on the 371 from 372.
I heard there has been a 2 ring 371 as well but rare A a single ring 372 one yr. I have seen that personally.


Do a Google search will bring you to some good ones on here that I've read in the past

 

[Westboastfaller]

bothl the 365 and 371 may have the HD 6 carb but later 371 went to the HD 12 before the 372 come.
None of this proves anything though.

 

[Westboastfaller]

371 front chain adjuster
And non see through gas tank.
365 may not

This doesn't prove anything

 

[Karl2020]

Ok thanks for all the good suggestions to check! I'm thinking it is indeed a 371 and not a 372. I don't know what he did then with his old 372. Will remain a mystery lol...

 

[huskihl]

365 will say 48 on the right side of the base. 371/2 will say 50

 

[Woodslasher]

Likely a 371 of 365
Clutch drum my have holes in it for a early 371 some had a three point mount on the inside dog. Yes the top is a 371 with orange snaps.front of the top cover I believe is different on the 371 from 372.
I heard there has been a 2 ring 371 as well but rare A a single ring 372 one yr. I have seen that personally.


Do a Google search will bring you to some good ones on here that I've read in the past

I just redid an “Air Injection” 372 with a holey clutch drum and I believe it originally had a single-ring piston. I also think it has orange clips as well.

 

[Karl2020]

Just an update on this saw. Based on all the suggestions from the people who replied, I'm going with this saw being a 371. The final deciding factor was the holes in the clutch drum. Even the single piston ring didn't rule it out since the new OEM Husqvarna piston i bought was advertised as a 372 part# but only has a single ring.

I got the saw all back together and running like a top! It's got good compression and the crank and carb hold pressure where there were leaks before. It idles and revs great. I ended up replacing piston, crank seals, muffler, air filter, fuel line/filter, carb kit, handle, brake lever, AV mount. And last but not least, a new "372XP" decal to replace the 365 Special one that was on there (they don't make 371XP one anymore).
_____________________

Lastly, and this should probably be a separate post on it's own instead of here, but i'm going to say it here anyway. I've read a lot of ppl debating the need for a little mysterious o-ring Husky designed to slip over the clutch side crank shaft and seat beneath a bushing that goes over the shaft, see pic (just the bushing, not the o-ring underneath it). There's a few good YouTube videos promoting the need for this o-ring. The idea is that the space between the bushing and crankshaft is a possible source for air leak without the little o-ring. I ended up replacing this tiny o-ring when i redid the seal. But I'm not 100% convinced though it's necessary as some suggest. And here's my reasoning why:

1) The fact that it's so delicate and fragile. How can this o-ring possibly withstand the spinning motion of the inner bearing race and bottom of bushing where it's seated for more than the second or 2 the moment after you fire up the saw? Doesn't seem robust enough. But the counter argument can be made: what's its purpose otherwise??

2) I'm not an expert on these things, other than what i can observe with my own eyes and logic. But let's say the bushing actually does spin at the same speed as the shaft and inner bearing race, then my point #1 above is moot since it won't experience rotational friction, sandwiched between these parts. So maybe it actually does stay intact for the lifetime of the saw, or however long its failure rate was designed to be. I have to admit, i can't rule out for sure that the bushing DOESN'T in fact spin at the same speed. Maybe it does, and again i'm wrong in point #1. I'm hoping someone with more knowledge can verify this for me. I'm genuinely curious. But..if that's the case, then why not just put some RTV gasket maker here instead of the little o-ring? Seems to me a little RTV will do the same trick.

3) When i replaced the crank seal with new, it still leaked air from the space between the bushing and shaft even though the o-ring was there (bubbles when i poured some gas around the seal). I was pretty frustrated at this point. This was my first time doing these seals and i failed...not a good feeling. But then i looked at it closer and realized i hadn't evenly/perfectly pressed the seal into the casing. I tapped it in a little more on the high side, and just like that the pressure held and bubbles completely disappeared. It held pressure perfect now. This point on its own doesn't rule out anything about the need for o-ring or not, just the need to make sure seals are pressed in evenly. But the point i'm trying to make is why were there bubbles between the bushing and shaft in the first place (o-ring installed) but went away once the seal was tapped in and seated evenly? You'd think there would ONLY have been bubbles around the seal's outer rim to begin with and NOT coming from the bushing/shaft space.

4) The two screws holding down the oil pump housing don't have gaskets or o-rings to seal them. Yet they don't leak air when you perform a pressure test, despite the fact that they terminate inside the crank case. They only leak air if you loosen them right out. How is that? Maybe because the thread of the bolts is a torturous enough path to prevent air leak. If that's true, then I'm suggesting once you thread the clutch back onto the crank, it similarly seals off the bushing space.

Anyway, these are just my observations on this saw. I realize that no 2 saws are the same. I would still probably recommend to others to install the o-ring since that's how the manufacturer designed it. I think the next time I do one of these saws though, i'm going to experiment without the o-ring and see what happens. I'm very happy with how this project turned out. Like a new saw again! Thanks everyone for your advice.

 

[John Stryker]

You're right that the bushing and o-ring are being held in place to the crankshaft, and make a seal with the force of the clutch being tightened down. I wouldn't try RTV between the bushing and crank because it might be hard to take the bushing off later.

 

[huskihl]

You're right that the bushing and o-ring are being held in place to the crankshaft, and make a seal with the force of the clutch being tightened down. I wouldn't try RTV between the bushing and crank because it might be hard to take the bushing off later.

Any sealant actually works fine. When do you think about it, there’s no reason to ever take that bushing off. If you were splitting the case to change the bearings, the splitter would push it off without any extra effort

 

[Karl2020]

Speaking of cranks. Who here can tell me at what point I need to service the bottom end of a saw? The 4 chainsaws and 2 sleds I've rebuilt have all only needed top end piston and some a new jug. Actually one sled i had to redo bearings and seals too. But never a crank on any. Back to chainsaws specifically: I'm assuming crank and bearings should be fine as long as it rotates smoothly inside the case and no obvious damage? The chainsaw manual just talks about the connecting rod. Something to the effect of "a bit" of side-to-side play on the con-rod is acceptable but no up and down play. Two questions then:

1) Connecting rod- What is "a bit" of side-to-side play versus too much and needs to be replaced?
2) Crank and bearings- At what point would you say they should be serviced or swapped out?

Thanks,
-Karl

 

[cuinrearview]

This thread needs some @Gaudaost

 

[Karl2020]

This thread needs some @Gaudaost

I'll have to check him out then! I don't get the reference (new to this site), but sounds like he's got some good tips.