Why do I feel my driveline vibrate more the harder I turn it? Did a motor swap and it did with the old motor too, almost seems more now although i did up the power too. Does it full trim up too at like 70mph. Gimble and u joints seemed smooth by hand and took grease in August when I finally got this together. Alignment was good and checked. Coupler is unfortunately ungreasable so I have to just pack some in there.
I almost have a on plane slippage problem like once a year too. Ill be on plane playing with the stick on rougher water and then all of a sudden it revs up and doesn't grab good till i pull it back down. No slam or clunk and i go on about the season. Is it possible that the coupler or drive hub could have an intermittent slip ? It's done it once a season for 3 seasons. Or are my 2 problems related?

Summer89,

Worn cone clutch?

Thanks. Brad.

Brad, I heard if those cone clutches get worn it'll cause shifting issues. My shifting is good. And if they're worn enough to be doing that what I have going on, then they are completely cooked and I should be having more issues. But I've also heard if a couple or Hub slips once then they just keep slipping and don't really do it intermittently.

Summer89,

That was why the question mark. The hub is also a possibility, as there are really only two places slip can occur without sh!t really going sideways: cone clutch and hub. A new hub is a relatively cheap fix and pretty non-invasive to do.

Thanks. Brad.

I did just put a new prop on this season. I reused The Hub from my old one and it was the solid Flo torque one for over 400 horsepower. It seemed to go in but I wasn't struggling to put it in couple Bops with a hammer and some WD-40

The vibration and when it does it points to U joints

That was my thought too -- and just because they feel ok by hand, does not mean that they are ok under load.

Yeah there was no resistance to them. I was kinda thinking them. And adding 150+ hp and still running them didn't help. And they took a beating last weekend at the local river rumble. Luckily I have only 2 more weeks before winterization and storage. Sounds like a next year problem.

Back to the cone clutches, so they can slip intermiintermittently and not get destroyed? I have no shifting problems, a shower, and when it does it it doesn't feel like a neutral rev it still has some load but just starts to lose speed.

Prop cavitating/airation?

Cone clutches don’t slip once it’s in forward or reverse. A bad cone clutch will just have a delay when shifting it into gear. You slip issue sounds like the prop is cavitating