Can Alpha One Drive Slip ??

[Dinows]

I put the boat in the water today and when I try to plane it (1988 Searay twin 350 mercruisers Alpha ones) the port engine revs up like there was no prop or I was in netural halfway into the plane and I have to back off. There is nothing wrong with the prop as I pulled it off and had it inspected. Any ideas
Thanks in advance

 

[NHGuy]

Re: Can Alpha One Drive Slip ??

You could have a spun hub allowing prop slip.

 

[Dinows]

Re: Can Alpha One Drive Slip ??

You could have a spun hub allowing prop slip.

I had that checked out and it was fine

 

[Bondo]

Re: Can Alpha One Drive Slip ??

Ayuh,... Then it's a striped coupler, or striped gears...
An oil sample will have metal in it if it's the gears....
Pulling the drive will expose a Bad coupler...

 

[Dinows]

Re: Can Alpha One Drive Slip ??

What exactly happens when the coupler goes? It only revs up when I try to plane it

Thanks

 

[Bondo]

Re: Can Alpha One Drive Slip ??

What exactly happens when the coupler goes?

Ayuh,... It Slips....

 

[carcraze]

Re: Can Alpha One Drive Slip ??

The coupler has a female spline that provieds the connection to a male spline on the drive if it strips then the drive will not be turned by the motor.

The other thing that coems to my mind based on my experiance is make sure you trim is set right as the drive could cavitate.

I know even trimmed all the way down with my twin engine Mirage if I am at the right point where the boat is not on plane and I am plowing along, happened while I was pulling the kids on the tube, then I try to power up my starboard engine will cavitate and pull air through the prop. I have to reduce power and allow the boat to sink a little and then power back up.

Maybe I have issues with my boat as well but it appears in my case that I need a sligtly different driving technique.

Just a thought.

 

[fishinpa]

Re: Can Alpha One Drive Slip ??

It can be hard to determine if you have prop slip from visually inspecting some props!
some are easily noticable while others you just can not tell the hub is spun ......
I would say mark them with a paint pen and run it see what you get ,

before diving in and tearing things apart!






fish

 

[Dinows]

Re: Can Alpha One Drive Slip ??

OK I will mark the hub insert and also try taking it up on plane with the drives up a little. I have NEVER abused the drives or done a "hole shot" If the coupler was bad shouldnt there be some noise or grinding smelling or something ? I hate to haul the engine if thats not the cause
Thanks in advance

 

[texomatom]

Re: Can Alpha One Drive Slip ??

Are the props both RH rotation? If so, swap them and see if the problem moves with the prop.

Tom

 

[bigdaddypt]

Re: Can Alpha One Drive Slip ??

not necessarily. I've had a slipping prop that did nothing but rev up and another one where it made the boat vibrate so bad that a screw came out of my windshield.

 

[carcraze]

Re: Can Alpha One Drive Slip ??

I believe couplers generally go bad more due to mis-alignment. It is a good practice to check alignment every spring.

Maybe a hole shot is not what is needed but maybe a little quicker throttle to get over to plane. You should be starting with the drives all the way in or down to get the bow over. I have tabs so I always have them full down as well which helps but I can not slowly advance through the PLOW stage mind you I do not do hole shots either. My drives are not counter rotating which I assume does not hekp matters.

Check the coupler and the prop hub first of course so you do not hurt anything any further if you have a mechanical issue.

 

[Dinows]

Re: Can Alpha One Drive Slip ??

OK I will go to the boat tomorrow or Sat morning at the latest and try what everyone said, will switch props. Dont give up on me yet and thanks for the help

 

[dockwrecker]

Re: Can Alpha One Drive Slip ??

I'm with Bond-o. I've had it happen to me on two different boats, one Alpha and a Bravo. Coupler slips, then nothing at all. I had to be towed 62 miles off of Lake Powell with one of them. Little to no warning of a problem, both boats had about 600 hours on them. Both of them required pulling the motor to change.

 

[Dinows]

Re: Can Alpha One Drive Slip ??

No one may get this message before morning but if you do (before I get to the dock) a backyard mechanic said that if you mark the inside of the coupler and the same place on the housing inside the boat at the rear of the engine with a marker and run the boat, you can tell if the coupler has slipped if the marks dont line up after the run. Anyone know anything about this ?
Thanks Dino

 

[nola mike]

Re: Can Alpha One Drive Slip ??

No one may get this message before morning but if you do (before I get to the dock) a backyard mechanic said that if you mark the inside of the coupler and the same place on the housing inside the boat at the rear of the engine with a marker and run the boat, you can tell if the coupler has slipped if the marks dont line up after the run. Anyone know anything about this ?
Thanks Dino

you'd want to mark the coupler, and the drive shaft entering it.

 

[Dinows]

Re: Can Alpha One Drive Slip ??

Well I went to the boat yesterday and treid what was suggested and the damn thing wouldnt act up. I took it up on plane twice and maxed it out to 4000 Everything was the same on the boat except I tried it in the river last night and when it was acting up I was in pretty rough seas. Is this common with a coupler to act this way ?

Thanks

 

[carcraze]

Re: Can Alpha One Drive Slip ??

I would not think it was the coupler, if the rubber goes than I would think it would slip under any conditions. Same if the spline was stripped.
When I had my prop hub give out I was not going anywhere fast, I had a spare on board and changed it right there or it would have been a long ride or a tow for sure.

It sounds like cavitation of the drive to me, but again stranger things have happned.

 

[Dinows]

Re: Can Alpha One Drive Slip ??

Is cavitation a common problem, is there a cure ?

Thanks

 

[carcraze]

Re: Can Alpha One Drive Slip ??

Well the boat I have now is the first twin I Have owned. My past boats if the conditions were right would cavitate but not too common really other than the jacked up outboard on my ski boat but the drive was set high. It would pull air through the prop really bad had to juggle the throttle till it planed out.

When I had my twin out the port pulled air through the prop but only when I was playing around before being planed out. It does not do it too often though but I know when I hear it.

Not even sure that is your problem, mind you if you had no issues in calm conditions it could be. I would also think it could also b affected by how the well the engines are throttling up together. I had mine out today and did not seem to do it at all.

Maybe just getting use to driving it will cure it as you get use to it.

I am sure others with more experiance than me can chime in.