Chainsaw Repair

TTT looking for info

Some dealers used to put the 5000 top on a husky 50 to make what is called a 50 Magnum.

(Back in the 80's we were selling a Husqvarna 50 Magnum. This saw was created in Charlotte, NC by the Husqvarna Distributor owned by Jim Thompson, The guy that made Husqvarna as far as I'm concerned. They brought in Partner 5000 cylinders and pistons and put them on 50 Rancher (the old white top) saws. These saws were awesome. The first one I received we got out of the box on Thursday and blew the competition out of the water on Saturday at the Races. Back then we had Chainsaw competition's on monthly bases. Husqvarna Sweden made them stop building them in the states. We built some ourselves after they stopped. It was a simple bolt on with no modifying at all. Someday I'll tell you more about the old Husqvarna distributors that made Huqvarna what they are today.)

Maybe I am wrong on the early smaller bolt pattern on early 50's stuck in my memory.  Because of reading this again.   

That is the model w/ smaller bolt pattern IIRC .
Shep

@Roanoker494  said

I have worked with many 50-55 series Husqvarna saws and have become very familiar with the parts interchangeability. In my experience 99% of all parts are compatible between the models 51 and 55, not 100% because some of the 51's did not have the air injection. The model 50 made several changes over the years and not all parts are compatible from all years. Before 1987 the model 50 had a smaller opening in the crankcase for the piston/cylinder so modifications are required to install a 51/55 top end onto the pre 87 model, though no mods are required to install the pre 87 top end onto a 51/55. The 50 also has the different choke system which, in my opinion, is inferior to the 51/55 setup. There was also some changes between the 50 Ranchers, commonly found with a white top cover, and the later 50's, commonly found with a grey or black top cover. The major differences were cosmetic with the recoil cover and chain brake assembly, you can not use the brake handle/flag from a 50 Rancher on the later style brake cover but you could swap the entire assembly without issue. I have often heard about there being different bolt patterns on the cylinders but I have yet to ever see it myself with having worked on saws made from 1983 through early 2000.

Parts numbers for the closed port
Complete top end 503971871
Piston alone 503168771

Another SB

From May 1989, serial number 9190006, the “50 Rancher” is replaced by the “50 Special”. The introduction of the new model means three big news:
1.
2.
3.
New cylinder/piston, in order to give the saw higher efficiency over a wider rpm register.
New chain brake equipped with a so called knee link. The new brake is easier to use and does not release involuntary.
New SA-silencer, in order to receive a more effective spark arrestor system.
New version numbers
967 05 13 replaces 967 05 14 replaces 967 05 15 replaces 967 05 52 replaces
1. Cylinder/Piston
Technical specification
Displacement cm3/cu. inch Bore mm Stroke mm Power output kW/Hp Weight, saw body kg/lbs.
967 05 03 (SA-silencer) 967 05 04 (Standard-silencer) 967 05 05 (France) 967 05 51 (Australia)
50 Special
51/3.1 45 32 2.2/3.0 5.3/1 1.6
50 Rancher
49/3.0 44 32 2.2/3.0 5.3/1 1.6