Motor comes up out of water

[Saltydawg2]

FINALLY got to go out on my new to me toon. Beautiful trip on High Rock Lake. I noticed on a couple of occasions after cruising at a higher speed, RPMs raced up, and prop was fighting for water. Lake was pretty much smooth at the time; no wakes. I would back off, and engine would bite, and I would be back on my merry way. The engine is a 1987 Evinrude 60 HP. When I look at the engine while idling, the water level is up to the top of a bolted plate, just below the lower pivot point of the motor. It is a 20' Sweetwater with 19' pontoons, also 1987, and I weight about 130#. That would possibly the back a little while I was looking at it. The holes you put the muffs over are about 5-6 inches below the bottom of that plate or about 9" below the water level. Is the pontoon planing, and causing the engine to rise out? Don't really know the questions you will need answers to, before helping me, and it got too dark too fast to snap any photos. Thanks for any stabs in the dark.

 

[Silver Eagle]

Re: Motor comes up out of water

Can you adjust your trim while moving? It sounds like your prop isn't getting any water so lower the motor.Also check to see if your prop is loose inside. try to turn it by hand with the motor shut off.

 

[crb478]

Re: Motor comes up out of water

Can you drop the motor one hole? Can you transfer any more weight to the back of the boat? It sounds like it is not deep enough at speed, and it will only be worse with rough water or with more people up front. Fine tuning the set up can probably fix the issue. If not maybe a jack plate that will set the motor back and lower.

 

[Saltydawg2]

Re: Motor comes up out of water

I would have to trim top of transom to lower motor. Not against that, but would like to try something else, first. The only thing up front are fenders, and vests, so no real weight to transfer. I was by myself in the boat when it did it.

 

[MinUph]

Re: Motor comes up out of water

Try just moving the stop pin down a hole so the motor with be tilted inward a bit more.

 

[Saltydawg2]

Re: Motor comes up out of water

Thanks for noticing. I'll drop it down to the last hole, and see how it does!

 

[MinUph]

Re: Motor comes up out of water

Try one hole at a time.

 

[crb478]

Re: Motor comes up out of water

I agree with moving it one hole at a time. Also a four bladed prop may help you keep more bite on the water.

 

[HarborRat]

Re: Motor comes up out of water

Motor height looks close enough to me. Sounds to me like you spun the prop. The inner prop is pressed in with rubber that goes bad and slips at high RPM. Scribe a line on the inner and outer hubs and take it for a ride (or just see if you can twist the prop by hand while in gear). If the scribe line moves that's the problem. A shop can fix it for under $50. Google "spun prop".

 

[Saltydawg2]

Re: Motor comes up out of water

I did drop it down one hole. I had looked at it wrong, and thought I was in the next to last hole, instead of next to highest. I will put a scribe mark, as you suggested, HarborRat. I might look at a four bladed prop, but I haven't really gotten up to speed on the whole prop thing, yet. Don't have a tach, but understand would need one to do it right. Also, need to take the wife on a couple more rides to pave the way for more money for toys.Coming up on the weekend, and still not quite ready to run with the big dogs at the ramp. I'll try Monday, unless I just go for it..

 

[crb478]

Re: Motor comes up out of water

Do the free things before spending money on things that might not be needed. You will want a working tach before you try to change props, if the prop is even a problem.

 

[Silver Eagle]

Re: Motor comes up out of water

So what is the Answer?

 

[Saltydawg2]

Re: Motor comes up out of water

Dropped motor down one hole(middle hole). Seemed to work better, but still did it. I wonder about this, though. If the previous owner pulled a tube behind it, which I think he did, would he have raised the engine higher to account for the additional drag? It's a small craft, with a fairly small motor. Don't really know what "normal" position would be, but seems like it could be closer to the bottom, rather than midway. Any thoughts?

 

[MinUph]

Re: Motor comes up out of water

When my motor is fully down it is past vertical. Yours looks like it is tilted up past vertical on the outward side. I can't say about pulling a tube as I don't do that. But If it were me I would try another hole down so the motor is at least vertical sitting still. It looks like you have power trim / tilt so you can adjust it on the fly. Right now you should be in the middle hole. Try another one and see. If it still doesn't seem right try the last one. I run a little trimmed up. As I said mine is way down and it runs smoother trimmed up just a little. I can hear this. Don't consider the last owner. Some have no clue about these things. Have fun.

 

[ahicks]

Re: Motor comes up out of water

An attempt at too sharp a turn can ventilate the prop too. If this is happening going straight, I like the idea of scribing a line on the hub and prop to see if you haven't spun the hub. Doesn't happen often, but it does happen! It's something you can check pretty easily, so there's no point in putting up with a problem like that.

 

[Bamaman1]

Re: Motor comes up out of water

I have a 1985 Starcraft 24' pontoon with a Yamaha 115 hp 2 stroke. When a couple of people sit in the front of my boat, it has a tendency to ventilate a little. I just have to ask them to sit in the back.

My motor is mounted as low on the transom as it will go. I've found that running the motor with the anticavitation plate parallel to the toons is the best place to run. Moving the engine up and down if you had power trim doesn't do much for a 2 toon boat.

You may find that another propeller will help your problem. Otherwise, you could have your transom plate cut down a couple of inches.

 

[Saltydawg2]

I finally had a chance to monkey around with the motor. I was by myself the other day, and found the same problem occurring. I took my GPS, and was running about 19 miles per hour, which I thought was pretty good. Motor did fine, even when I gave it the gas from a dead stop. Did not lose bite at all. Only when I was up to 17-19MPH for 1-2 minutes did it lose speed, and the engine race. Seems to me that if it were a spun prop, it would do it under the strain of pushing the pontoon up to that speed, as opposed to doing it when cruising. I continued to let the motor down, with no real change, except the steering got much harder, especially on the bottom hole. That is not the way to go. I did, however, put a line across prop hub to verify hub is not slipping, next time out. I did notice, though, as I was moving,(not too fast), I could look down at the motor, and could see WAY down into the water, almost to the lower fin, just above the prop. Is that about right, or is that an indication of something else? Thanks for all the help, and sorry this thread seems to go on forever, but other parts of my life seems to keep interfering.

 

[Saltydawg2]

Sorry for double post..

 

[crb478]

If it is getting difficult to steer, but still loosing its bite it may well be because of the turbulent water that is hitting the prop at that speed. I would raise the motor back up some where the steering felt better and the hook up was the same. Does your pontoon have underskinning? This can slow you down if it doesn't and add to the turbulence. I have a very flat type of aluminum hydrofoil on my boat. It was on there when I bought it and I took it off and found that I lost a little speed due to the turbulent water that hit the prop. I put it back on and it seems to flatten out the water right as it hits the prop. I am generally not a big fan of hydrofoils, but it this case this unusual looking flat aluminum hydrofoil seems to work.

 

[Saltydawg2]

Thanks for replying.I actually have a hydro foil that I took off a motor a few years baak, that I just put on, this morning. I raised the engine back up two holes, to get the steering more neutral. Weather seems to be closing in, this afternoon, so may not be able to go out this weekend.Standing on a lightning rod in the middle of High Rock Lake is something I am being advised against. So, we will see...