Husqvarna 50/51/55 parts interchange

[Roanoker494]

Here is a service page I got from ModifiedMark on the difference in crankcase openings for the earlier models. I found it helpful.
http://www.arboristsite.com/attachments/chainsaw/166414d1293770137-husqvarna-50service1-pdf

That is the first time I have actually seen the service bulletin. I thought someone said that bulletin stated there was a difference in the cylinder mounting pattern? I personally see nothing there that even hints at the idea. Looks like the "special" had to go through new "testing procedures", undoubtedly to make the EPA happy, and they changed the block slightly so that the new larger top end could not be used on the older non EPA approved case. This bulletin looks to be nothing more than a factory provided blueprint on how to do the swap anyway, Husqvarna just had to cover their tail by telling the dealers not to do it.

If the piston has windows it is closed port

That is a very good way to know but not many people are going to let you take their saw apart to look at the piston.

Take a look at post #2 in this thread http://www.arboristsite.com/chainsaw/167778.htm to see the differences. If you were to look through the plug hole with a small light you would be able to see the open or closed transfers on each side of the cylinder.


Parts numbers for the closed port
Complete top end 503 97 18-71
Piston alone 503 16 87-71

 

[Wagnerwerks]

Other dif between 50 rancher and 50-55

I'm rebuilding a 1983 50 Rancher right now and was about to post on differences in a new thread when i stumbled upon this one. After so much searching I thought it would be nice for the future dude that finds everything in one spot.

How about the oilers in the ranchers? Are they interchangeable? I keep getting replacement #'s that end up as a 55 rancher oiler plunger gear. I just want to make sure as they cost little until I get railed for shipping.

Also, what tools do I have to have to pull the oiler worm gear? There are 2 dif tools I keep ending up at after # searching. I don't know if both are required or just one, but I don't do these saws often enough to get "extra tools". I have enough of them for VW's:biggrin:

Here's the puller tool I found on the cheap, but it may not work. eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Thanks guys. OP, I didn't want to thread jack, but this seemed like the way to go to keep this all together.

 

[Roanoker494]

I'm rebuilding a 1983 50 Rancher right now and was about to post on differences in a new thread when i stumbled upon this one. After so much searching I thought it would be nice for the future dude that finds everything in one spot.

How about the oilers in the ranchers? Are they interchangeable? I keep getting replacement #'s that end up as a 55 rancher oiler plunger gear. I just want to make sure as they cost little until I get railed for shipping.

Also, what tools do I have to have to pull the oiler worm gear? There are 2 dif tools I keep ending up at after # searching. I don't know if both are required or just one, but I don't do these saws often enough to get "extra tools". I have enough of them for VW's:biggrin:

Here's the puller tool I found on the cheap, but it may not work. eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Thanks guys. OP, I didn't want to thread jack, but this seemed like the way to go to keep this all together.

The oilers are the same and the tool will work to pull your gear, for $5 I may consider getting one of those myself. If you are planning to replace the oiler gear anyway I would just heat it and pry it off with a screwdriver. The gear is made of brass and it should not take much heat to get it loose, though you will surely need to change the crank seal after using heat.

 

[Wagnerwerks]

Yeah. The crank seals were the plan, but now I may even do bearings. This saw is super nice looking and I figure after I dropped 70 bucks in parts it will be very solid. I wasn't planning on replacing the worm gear as it looks fine. The plastic one on the oil pump was toast from sawdust i believe. Thanks very much for the info. I haven't gone this deep into one of these before.

 

[Wagnerwerks]

Yeah. The crank seals were the plan, but now I may even do bearings. This saw is super nice looking and I figure after I dropped 70 bucks in parts it will be very solid. I wasn't planning on replacing the worm gear as it looks fine. The plastic one on the oil pump was toast from sawdust i believe. Thanks very much for the info. I haven't gone this deep into one of these before.

That tool does not work on a 50 series. It's for some smaller worm gear. Still looking for the right one.:msp_confused:

 

[SawTroll]

tyvm for that info....the 50 special is my favorite saw... the 1st husky i bought new..zero issues...cut alot of wood....my only saw for a long time....not much wear...ring..piston skirt ..cylinder....did some mild porting..i hope....but..if i want to make it go faster...what can i do....iam not sure what NOS means..it sounds fast....ty

The 50 Special used the same 45 mm P&C as the 51, and had the newer style case and bolt spacing, while the 50 rancher and streight 50 had the old one and 44 mm P&C. At least, that is the "official" story.