Yamaha 50 2 stroke rebuild questions

Turpentine

Cadet
Joined
Apr 27, 2023
Messages
7
I have an extra power head for my 85 model 50 2 stroke that I would like to rebuild. It lost the lower bearing on the crank and slightly scored the bottom cylinder And piston. Now to my questions. I want to do it right but I want to weigh my options. i don't mind spending extra dollars to do it right the first time. I plan to have Jeff Dunn bore the crankcase And do the machine work. My issue is what to do for a crank. I could possibly put another bearing and piston on the existing crank but if I did that I want to make sure that crank is good to go and is going to last before I reuse it. That's option one. Sort of. I would like to know if their are any reliable shops that can true and check that crank out? Who does good work on these pressed cranks?
2nd option. I see a lot of WSM new cranks for sale. Are these decent, reliable cranks as far as going into a stock motor. I do not plan to mod or hot rod it. Mainly just a fishing and duck hunting motor that will be turning stock rpm's.
I guess option 3 would be possibly sending in my core and buying a remanufactured crank. Certainly not sure that is what I would like to do as I wouldn't want to buy one with cheap bearings. It needs to be right.
Thanks guys for any advice. As for the head I'm running now, I plan to put the rebuilt head in once it's done, then refurbish and keep the old head for a spare. You know, new rings, that sort of thing. I like having spares around.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,084
O/S factory pistons are listed as NLA.----New factory crank assembly is about $1200.----So check availability of parts in your area first.
 

Turpentine

Cadet
Joined
Apr 27, 2023
Messages
7
O/S factory pistons are listed as NLA.----New factory crank assembly is about $1200.----So check availability of parts in your area first.
The one thing I'm trying to avoid is buying a new $1200 crank but it is an option. I don't mind going with aftermarket pistons but want to use quality components for sure. The crank in this old head may be usable but I need a professional to check all that out and have no idea who does that.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,096
I sent my C40 crank to NC and got a rebuilt back and it has been great.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,096
Took a little while, but I found it.
Carolina Tool and Machine in Wilmington NC
 

Turpentine

Cadet
Joined
Apr 27, 2023
Messages
7
I can remember a while back reading on on forum about a shop in NC but since Covid my memory is gone and I cannot find the information. Is that C40 the 3 cylinder as I remember Yamaha having a 2 cylinder configuration very similar to mariner for a while.?
 
Top