Frustrated with variable speed system on OMC 1200

[matthause]

Well after rebuilding my variable primary sheeve it keeps coming loose off the engine shaft. I doubled up the set screws and used loctite. There is no bolt hole that goes laterally in the engine shaft. I am thinking of just ripping it out and doing a sprocket and chain set up. Would somewhere in the middle be good enough for gearing? I know someone has done this (Bryan) on here and im really needing help.

 

[Tazza]

Just how is it secured to the shaft? does it use a key or just set screws?
If it has a key, there really is no reason for it to come loose.

 

[matthause]

Just how is it secured to the shaft? does it use a key or just set screws?
If it has a key, there really is no reason for it to come loose.

It uses a key (which is new) and two different set screws. The shaft indent is wallered out where one of the set screws is supposed to go into.

 

[Tazza]

It uses a key (which is new) and two different set screws. The shaft indent is wallered out where one of the set screws is supposed to go into.

Yeah, that could be an issue.... Can you drill and tap new holes in the pulley and drill the shaft for the new set screw position? Rotate it about 90 degrees from where it is now?

 

[matthause]

Yeah, that could be an issue.... Can you drill and tap new holes in the pulley and drill the shaft for the new set screw position? Rotate it about 90 degrees from where it is now?

Thanks for the reply! Because the keyway is there i cannot rotate the pulley without some major machine work (not to mention removing the crank). So i am thinking either a custom made key, or just run a chain at one speed and make the thing work.

 

[matthause]

Thanks for the reply! Because the keyway is there i cannot rotate the pulley without some major machine work (not to mention removing the crank). So i am thinking either a custom made key, or just run a chain at one speed and make the thing work.

Ok so Im a dumb ace...got what you said right after i posted. Yes i am going to try new set screw locations and go from there. I am just so leary of spending alot of money on belts and machine work when im not sure if it will work. -Matt

 

[Tazza]

Ok so Im a dumb ace...got what you said right after i posted. Yes i am going to try new set screw locations and go from there. I am just so leary of spending alot of money on belts and machine work when im not sure if it will work. -Matt

I know what you mean. If you have the gear to do the new set screw, it will just cost you some time. I bet the belts aren't cheap either.

 

[M1782t]

I know what you mean. If you have the gear to do the new set screw, it will just cost you some time. I bet the belts aren't cheap either.

Just looked at a machine today with the same problem, what did you end up doing with yours? I could also probably make you a custom key if you still need one, I'm retired and make parts for a hobby. Is the shaft/bore tapered or straight?

 

[njclimber]

Just looked at a machine today with the same problem, what did you end up doing with yours? I could also probably make you a custom key if you still need one, I'm retired and make parts for a hobby. Is the shaft/bore tapered or straight?

I've re-engineered the sheaves for under $100, if you want help just email me [email protected] i've spent hundreds of hours with skid steer variable drives