Drive Slip

Willhound

I've recently had an issue crop up that has me a bit perplexed. About the last 4 or 5 runs, when coming up on plane I could sense (and hear) that I had slip in the drive line. But only the first time I come on plane for the day.
I should start by saying that I have now put about 160 hours on the boat and the issue has only been the last 20 of those. From the start I've always run with full fuel and water tanks and usually 2, sometimes 3 on board. I don't believe it to be prop slip or I would have had the issue from the start, I would think. The first time it occurred it felt like I had weeds wrapped around the prop, and when I stopped, briefly reversed, and then moved forward again I think I did see a mass of weeds float up. But the weird thing is, it only happens at the beginning of a run when leaving the harbour. Once on plane and running a bit I can stop, hammer the throttle and jump on plane with no slip whatsoever. My first thought was prop hub slipping caused by the first weed issue. But wouldn't that happen all the time? I also wondered about the cone clutch, maybe only happening until things warm up? But I would think that would get worse as things heat up?
Drive oil is good, no milk in tank and no drop in level. Anything else I need to consider?

randy56

Never had that issue, where it may work's intermittently,  had engine couple's go out before but when they fail. You cannot get on plane again and again. They slip, when you go to higher rpm. Low rpm's are ok.  And its best to head to the dock. Here is a short clip on cone clutch.  https://www.youtube.com/watch?v=Zr7VdIJBEEI

Willhound

Thanks @randy56. I have to admit I always pictured the cone clutch being further up the driveline requiring an engine pull or something to change. This makes me feel better that if that's what my issue is it can be a somewhat easier did. If that's what the issue is.

reneechris14

The bravo3 has no prop hub it all stainless steel , the coupler on the flywheel is rubber 

Willhound

Thanks @reneechris14 I seem to remember that about the props now. And I'm thinking a coupler would just plain fail. I've been thinking......maybe I'm getting bottom growth, just enough that it hinders when first heading out, but once I run a bit it scrubs off enough that I'm good the rest of the day. So maybe it is just prop slip. Think I'll just run it until it drops!

pistole

check your drive oil reservoir too

Willhound

Thanks @pistole. Drive reservoir good. Happened again on the weekend. First run up the prop slipped just a bit for a few seconds. Another 10 run ups onto plane the rest of the day, nada. Solid and steady. Water been pretty scummy in the marina lately. I'm starting to think just enough crud on hull to cause drag until it cleans off a bit. Only other thing might be cone clutch, but I'd think that would get worse as the drive heats up, not go away.

Liberty44140

Any chance your getting cavitation and not slip? Is the drive all the way down?

zaverin1

Ye slip is something totally different 
dirty bottom won’t create slip but drag which will translate to hard and long plane time 

Willhound

Drive all the way down but could be cavitation. I use the term prop slip but should likely say cavitation. 

zaverin1

That would be caused by a worn or damaged prop
or having a wrong prop
is she getting to the rpm needed to plane with this happens ?

Willhound

Prop is pristine. RPM is normal. All other operation is normal, RPM, top speed, cruising RPM and speed etc. 
Just that first initial getting on plane for the day. After that, I can go half a mile, come down off plane, hit the throttle and get right back on plane with no issues. And every time after that .

Handymans342

Willhound said:

Thanks @reneechris14 I seem to remember that about the props now. And I'm thinking a coupler would just plain fail. I've been thinking......maybe I'm getting bottom growth, just enough that it hinders when first heading out, but once I run a bit it scrubs off enough that I'm good the rest of the day. So maybe it is just prop slip. Think I'll just run it until it drops!

I think its the growth. Can you put your hand underneath somewhere and feel for it?

zaverin1

Has to be 

Dream_Inn

Growth is the only thing that make sense to what Willhound is saying.  The only way to know is to brush the bottom and drives right before you take the boat out the next time.  (or borrow a friends lift for a week )

reneechris14

Yes especially being the end of the year it has had a long time to grow.

Willhound

Yeah......IF I go out today it'll be early.