Re: With four people, I can't get it up.
 

Mike-- your ability to see the future is spot-on. I'm leaving in a few minutes to do exactly that. The top guy at the shop said, "Bring it over, I'll grab a few guys here, and let's take it out on the water."


I'll report back with what's going on and what they find.

Re: With four people, I can't get it up.
 

Just got back from the shop. (An authorized Mercruiser facility.)

Went out on the lake with their lead tech and two other techs (four of us total.) And of course, the boat performed perfectly. Popped right up on plane. With three guys across the back, it would still plane out, although it took longer, as you'd expect.

They were happy with the engine performance, WOT RPM (which was 4300) and the overall performance.

They had two possible explanations for what happened:

1. There were either weeds around the prop (I'm nearly sure there weren't, but not 100% sure) or we were taking off with a relatively heavy load in the midst of a weed field. Certainly possible given all the rapid weed growth in Madison lakes lately.

or

2. Something intermittent that will surely get worse and reveal itself as time elapses.

We left it as, "Well, if it happens again, bring it back, and we'll take a look at it again."

I guess that's all that can be done at this point. I think I'll bring a camcorder along for a while if it starts happening again. :rolleyes:

Re: With four people, I can't get it up.
 

Oh... and they specifically recommended to NOT switch to a 17-pitch prop at this point, as it would likely over-rev at wide-open throttle. Had the WOT RPMs been considerably lower, I think they would have recommended the 17.

Re: With four people, I can't get it up.
 

IMHO, you should be between 4700 to 4900 rpm with the Quiksilver Prop.

I base that on my setup: 18 ft Talari, 4.3 2bbl, 14.25x 19 Stilletto prop.

Can the encapsulated foam on a Mariah get waterlogged?

Re: With four people, I can't get it up.
 

I asked about waterlogged foam also, as well as the sundeck. That doesn't seem to be the case, as the whole boat is dry (not leaking anywhere), shows no signs of dampness, and was stored indoors over the winter.

The repair techs said that if there's a waterlog situation going on, the boat will almost certainly drip when it's out of the water for a period of time. When they had it in the shop a week ago, there was nothing that seemed obvious -- it wasn't dripping. It was indoors, on a trailer, for three days.

Re: With four people, I can't get it up.
 

One thing peaks my interest...

When the boat couldn't get on plane, it was still revving higher. This could essentially mean only 2 things. The hub was slipping, or the coupler was. I agree with what's been said - the hub was new and fit perfectly by a trained technician. I really don't think it was the coupler either... I'm at a loss on this one!!

If the engine revved higher, I don't think you have a compression, flame arrestor, spark plug issue, etc. If it's revving, it's making horsepower. Something was obviously slipping, but I hate to guess.

Re: With four people, I can't get it up.
 

I'm just not technically proficient enough to know which things could possibly present an intermittent problem. Can a coupler slip intermittently? Can a thrust washer slip intermittently? Is there something else that can cause a periodic problem but be perfectly fine other times?

I guess that's why I'm not a sterndrive tech!

Re: With four people, I can't get it up.
 

A slipping hub can be an intermittent problem at the beginning based on the load that it's under.

I have had the same happen to me, but it's been the things that you ruled out: slipped hub, debris or stick hooked on the outdrive, trim not tucked in.

Re: With four people, I can't get it up.
 

That's exactly why the only explanation I can think is that the prop is slipping in the water... ventilating, cavitating, badly shaped blades or something like that. But the prop seems to be rated as a good all around prop.

abillmann: where are you located? Maybe someone is close enough to you to try a couple different props.

Re: With four people, I can't get it up.
 

No, three: Or it was cavitating. That is what I've suspected from the start. But I'm new to this boat, engine and drive system, so I've kept quiet :).

Jim