Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: KilliansRedLeo on February 21, 2014, 03:57:54 pm

Title: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 21, 2014, 03:57:54 pm
If you plan to purchase one of these be careful and inspect closely. They are usually missing some clearly visible parts like bar studs. However I have also noticed that some are missing an essential part that is not so visible; the brass pulse tube! It is not there just a hole in the case. Search eBay for 372xp crankcase and have a look for yourself. You can easilly see it is missing in picture number 5 on the first auction by Hutzl.

I personally have never had occasion to remove the brass tube nor do I even know how to install and secure one so that it is air tight. Not only that but I cannot find the brass tube listed as an available part in the 372 IPL!
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: Spike60 on February 21, 2014, 04:25:13 pm
Good advice as usual.  :) And you're right about that brass pulse tube not being on the IPL too.

All of that stuff needs to be looked at closely. Some of it is fine, some not so much.  :-\
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 21, 2014, 04:38:33 pm
Plus 1! Spike60 have you ever come across how to remove and replace one. On every saw that uses this arrangement including the JReds that I have ever seen the pipe appears to be soldered in prior to the case being painted.
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: tlandrum on February 21, 2014, 08:15:02 pm
its a simple press in fitment
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: SawTroll on February 22, 2014, 12:31:47 am
Chinese aftermarket parts tend to be heavier than the originals, and generally are much lower quality. Not something I would want, for sure!  ::)
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 22, 2014, 05:51:13 am
Nikko, we have been having a discussion about possible differences in deck height between various models of the HVA 362/365/371/372 saws. Do you know if there are differences in deck height on these models or are they all the same. I have looked around the internet and on the Husqvarna site and cannot find this type of information.

 A friend and I have built several of the same formula saws. Sometimes you have to use a base gasket to get correct squish and sometimes you can get away with only sealant. I tend to think that the differences are probably in the aftermarket cylinders we are using but there could be design differences in the HVA crankcase deck height across various models in the same family.
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: Spike60 on February 22, 2014, 09:25:56 am
I've never had the need to mess with one of those impulse pipes myself. But you'd think that there would be instances where someone might need to order that as a spare part.

One thing to add here regarding cases is that there is a difference between the originals vs the new X-torq models. The skirt on the bottom of the XT cylinders is deeper than the originals, so the corresponding cut in the XT cases is also deeper. If putting an original jug on an XT case, you will have no problem. But you cannot put an XT cylinder on the original case. (unless you do some grinding) As far as deck height, I really can't say.

Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 22, 2014, 09:50:26 am
I don't believe we were using XT cases in particular, but that could be. In the current set we were both using 365SP cases, using the same jug and piston, Hyway BB 52mm with a Meteor Stihl 064 piston. I had to use a base gasket to get to .020 and Alan got away with no gasket (goo) and he is at somewhere .025-.027 IIRC.

My guess is that the AM jugs are what the difference is. I have two kits on the way and will measure them and post the results.
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: 660magnum on February 22, 2014, 09:58:56 am
For the impulse line in a after market crankcase . . .

You can get the thin wall brass or copper tubing from hobby sources in the brand name of K-S. Might be at the local model airplane shop or Hobby Lobby? The local hardware down the street from me has it.

The brass tubing is typically work hardened. You can anneal it though just like annealing a piece of steel.

If you are going to drive it into a crankcase as a interference fit, you cannot go more than size for size and will need to drive it with a shouldered mandrel
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 22, 2014, 10:06:01 am
Thanks Jim, I am looking at the clutch side of a 372 case right now. The tube appears to be z shaped in that the bottom of the z is inserted in the case, then runs to the right a little bit with the remaining leg sticking up. In the one I an looking at there appears to be some sort of bulge under the paint as if the thing were soldered or glued into the case prior to paint being applied.

I will get a couple pictures so everyone can see. I will photograph two examples.
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 22, 2014, 10:25:02 am
Here are two different examples a 372 on the left and a 371 on the right. it appears that the bend to the right in the brass tube is there to make room for the carb boot clamp. looking at an assembled saw the previous statement appears to be correct. I do not know the heat expansion coefficient of brass vs magnesium but I would think that you could lose the tube when putting the cases in the oven to remove and replace main bearings, which has never happeened to me.
Title: Re: After Market Husqvarna 362/372 Crankcases
Post by: KilliansRedLeo on February 22, 2014, 01:43:52 pm
its a simple press in fitment

Thank you Terry!