Yamaha Sterndrive lower unit

[chpperlvr64]

So heres my issue I have a 93 renken with a Yamaha sterndrive on it and when I bough the boat the sterndrive was not attached and all they said that they were told was needed was a transom shift cable so I got one put it on and put the stern drive back on when putting it back on I noticed that when I spin the prop the rotate the shaft the shaft wouldn't move but it would move if I tried it directly. I opened the top cover to inspect the gears and they look fine so I spun the prop and those gears didn't move either so I'm thinking its the lower unit any advice or thoughts on this would be greatly appreciated,

 

[Scott Danforth]

welcome aboard. unless your in gear, the lower will not drive the upper (the shifting is in the lower). if your in forward, the over-run clutch will allow the prop shaft to freewheel in one direction, however transmit power in the other. reverse is the opposite.

if it is your lower, good luck. very few yamaha sterndrives out there (since they only imported them for a few years), and parts are less available than OMC parts.

 

[chpperlvr64]

Scott I put it in gear going fwd and the prop spins put in gear going reverse and the prop spins freely now bear in mind I don't have the engine running when I'm doing this

 

[Scott Danforth]

when in gear does the prop spin freely in both directions, or only one?

 

[Bondo]

Ayuh,..... Welcome Aboard chipper,.... I donno squat 'bout these Yamahas, except they're rare, But,.....

Scott, aren't they cone-clutch drives,..??
Do they shift in the lower unit, or mid-section,..??

chipper, try shiftin' it from where the forward, 'n lower cables come together at the motor/ transom,.....

 

[chpperlvr64]

Scott it spins freely in both directions , bondo what would that do if I tried shifting it at the shift unit on the engine?

 

[Bondo]

It takes the controller, 'n it's cable outa the diagnostic equation,....

 

[chpperlvr64]

Bondo the cables are brand new

 

[Scott Danforth]

Ayuh,..... Welcome Aboard chipper,.... I donno squat 'bout these Yamahas, except they're rare, But,.....

Scott, aren't they cone-clutch drives,..??
Do they shift in the lower unit, or mid-section,..??

chipper, try shiftin' it from where the forward, 'n lower cables come together at the motor/ transom,.....

dont really know, guessing they are alpha-ish clones based on this picture with the shift shaft

however based on this IBOATS thread http://forums.iboats.com/forum/engi...a-sterndrive-shifting-problems-1990-l4-w-pics my guess is they could shift in the upper section, or the linkage thru the drive is more complicated than japanese stereo instructions

here is an upper at a salvage location http://www.shipwrecksalvage.net/yamaha-v6-43-upper-unit-outdrive-sterndrive-p-4300.html

 

[Bondo]

Bondo the cables are brand new

Ayuh,..... Just 'cause they're new don't confirm they're Right,....

Yer Diagnosin' the issue,....

Everything is Suspect,....

Maybe Capt. Ken will stop by,... He's My Go To guy for these things,....

 

[chpperlvr64]

Any ideas of what could be wrong or where I should start? Also are there any sterndrive that I could switch out with that would match to the existing housing?

 

[Bondo]

Also are there any sterndrive that I could switch out with that would match to the existing housing?

Nope,.... Not without swappin' Everything, from the pulleys to the prop,......

 

[Capt Ken]

I love when everyone starts guessing at how the Yamaha drive operates. Everyone knows it's magic and only the wizard knows
Remove the drive, push the shift fork either left or right, does the prop lock up in gear or not? If so, look at linkage, if it doesn't, it's the drive. If the gears in the upper looks good, then it probably broke the vertical shaft.

 

[chpperlvr64]

Ok well the boat will go fwd now but reverse is not existant took to sterndrive off check the fork in the unit and it moves easily the part that's still on the boat also moves easily , split the cases and moved the brass fork to fwd and the shaft moves when I spin the prop put it in neautral shaft don't spin put it in reverse shaft don't spin , I'm lost at what I need to do with this help me out