What now? a bad clutch?

[art_yatsko]

My '96 Crownline wouldn't get up on plane today. I checked all the compartments for water, stopped at a dock and scraped the grim off the water line and the barnicals off the trim tabs. On the next test ride, the RPM's are shooting to 5,000 and I'm hardly moving. At lower RPM's everything was fine. Just seemed to slip under a load?? There's plenty of drive oil, (which I do have to add often). Is there some kind of shear system on the prop that might be slipping. It's a 454 w/ a bravo one out drive.

 

[Don S]

Re: What now? a bad clutch?

May be a couple of things. Spun prop hub, spun coupler, slipping cone clutch in the drive, and now for the biggie. Dirty bottom. If you had barnicals on the trim tabs and a scum line on the sides, chances are you have the same on the bottom.
Check the prop, clean the bottom and see how it works.

 

[rodbolt]

Re: What now? a bad clutch?

add oil a lot to the drive oil resevoir ?

 

[art_yatsko]

Re: What now? a bad clutch?

Yes, it seems to eat a lot of drive oil. maybe half a bottle in five- seven hours....or is that normal?
The scum line ended pretty much at the begining of the bottom paint and the barnicales were loaded on the unpainted trim tabs (and some unpainted spots on the leg- the logo was covered, gasp!) doubt this would explain the 5000 RPM, WOT has always been 44-4600. (I guess it could have calvatated.....maybe prop has growth???)
Plan to haul this week: check the bottom and pull the prop. I'm assuming these two problems I can see. How do I test the the hub, coupler, and clutch? I this a job for a backyard mech a nick like me? I've got hammers in all sizes....

 

[stevieray]

Re: What now? a bad clutch?

Art - do you smell any burning rubber in the engine compartment? That would indicate a possible coupler problem. You can test the prop while it's still in the water by putting marks on the prop hub & on the lock nut that line up. Run it for a while & check to see if the marks still line up. If not, it's probably spun. Also check the prop condition - you may have hit something & damaged it - that will also cause the hub to spin.

 

[art_yatsko]

Re: What now? a bad clutch?

Thanks, no rubber smell. I did hit a rock a few weeks ago. I was idling up to a friend's dock. (He pointed to a spot in the water after it stalled the engine... what a guy.) I couldn't feel any damage to the blades, but I didn't try to force it around.
If I can feel the teeth on the lock nut, I could...ah,,,,

How do I mark it under water?

 

[stevieray]

Re: What now? a bad clutch?

I did hit a rock a few weeks ago. I was idling up to a friend's dock. (He pointed to a spot in the water after it stalled the engine...

This would have the tendency to point me in the direction of the spun prop hub. Is it a stainless prop or aluminum? I have seen stainless ones spin without a lot of blade damage, but if it's aluminum even going into soft sand will ding it up pretty good if it hit hard enough to spin. Marking it in the water may mean getting a little chilly - you would have to get in about 3 ft of water & trim it all the way up (with the engine off, of course) so you can see it. Use one of those red grease pencils or a good 'ol scratch awl. You will also have to get back in to check it after you run it. Brrrrr.

 

[rodbolt]

Re: What now? a bad clutch?

I am more concerned with your drive oil leak.
the drive is a sealed system and should NEVER require oil.
you may have a spun hub on the prop or a bad coupler. I would pull the prop for inspection.
but I would also pull the drive and find the leak.
while the boat is hauled and the drive off I would simply send the prop out to a prop shop.

 

[art_yatsko]

Re: What now? a bad clutch?

OK, thanks guys. It's a SS prop, and it did hit hard enough to stall. It stopped the engine, but didn't dent/bend the prop. I think you're right- spun prop. (Hope you're right too)

Now I didn't realize that the drive oil was a closed system (assumed leaking was normal). After all, it has that large reservoir right on top, with the low oil alarm, etc. The yard that stored it last winter did replace the outdrive cover assembly o-ring. They said they couldn't paint the outdrive because the o-ring was leaking oil. Maybe they hacked that up too. I'll check all when I get it in my driveway, and will keep you posted.

 

[Aquaman]

Re: What now? a bad clutch?

I this a job for a backyard mech a nick like me? I've got hammers in all sizes....

Thanks...I needed a good laugh!

 

[art_yatsko]

Re: What now? a bad clutch?

Hey guys, just wanted to say thanks and give you an update. My boat in the driveway and the prop off. The guy at the prop shop says it's not spun. He too asked about burnt rubber smell and suggested I poke around for rubber grindings up under the engine bellhousing. Changed his mind though when I discribed the barnicales on the outdrive. He claims the new anti-fouling paints don't work, and now that I powerwashed them all off (took 2.5 hours!), the boat should be fine.
He also suggested I replace the shaft seal behind the prop. It's the likely cause of my drive oil leak.
I'll check for rubber grindings, but I'm feeling pretty confident that the prop shop is right. That outdrive was covered, 1-2 inches thick!

I'm going to poke around the forums and look for tips on outdrive paint, removing the barnicale scabs, and how to replace that shaft seal. I'll post again if I find rubber in the bellhousing. Thanks for all the input.