1985 90hp yamaha rebuild help

[knight_time]

I burned up one of my cylinders not to long ago and im planning on resleeving all the cylinders while i have it torn apart. My question is what parts do i need to order is there a rebuild kit out there somewhere and more important than that if anyone has any tips and tricks to make it easier they would be much appreciated

Thanks

 

[robert graham]

Re: 1985 90hp yamaha rebuild help

Maybe it would be worth considering a good used 90HP very similar to yours instead of putting all the money into a rebuild of a 25 year old motor. If you could locate one very nearly the same as yours then you could keep your old one for parts. Just an idea, Good Luck!

 

[knight_time]

Re: 1985 90hp yamaha rebuild help

Maybe it would be worth considering a good used 90HP very similar to yours instead of putting all the money into a rebuild of a 25 year old motor. If you could locate one very nearly the same as yours then you could keep your old one for parts. Just an idea, Good Luck!

that idea has been tossed around but I got the motor cheap and was in great condition until my cooling line clogged up and the motor overheated, so i think im going to try to fix it before i go looking for a new one good news is i cant mess it up anymore than it already is
Thanks

 

[robert graham]

Re: 1985 90hp yamaha rebuild help

Another alternative might be to locate a good rebuilt powerhead, turn in yours on exchange. Could you just re-sleeve that one cylinder, or bore it out and go over on the piston? Once you find a good marine mechanic/machinist then your options may clear up. Good Luck!

 

[knight_time]

Re: 1985 90hp yamaha rebuild help

its looking like i might be boring it out .30 over

 

[99yam40]

Re: 1985 90hp yamaha rebuild help

have you checked to see if you can find .30 pistons and rings?
These are not like automotive motors

 

[knight_time]

Re: 1985 90hp yamaha rebuild help

have you checked to see if you can find .30 pistons and rings?
These are not like automotive motors

well with the bore my mechanic said i needed to look for .75mm pistons which ive found only problem is theyre dome top and im fairly certain i need flat head pistons

 

[robert graham]

Re: 1985 90hp yamaha rebuild help

Hopefully your mechanic/machinist is experienced working on outboard motors because they are different from automotive engines.

 

[knight_time]

Re: 1985 90hp yamaha rebuild help

hes done a few of them in the past ill know more this evening when i start tearing it apart

 

[GoogieMan]

Re: 1985 90hp yamaha rebuild help

check out http://www.wiseco.com/ProductSearch.aspx enter motor info to top left corner use this as a guide
shows .020, .030, .040 over