Ventilation / Prop issue 95 starcraft 3.0L

ronduth

Recruit
Joined
Jul 23, 2011
Messages
4
Hello crew,
First time board poster here.


My boat :
1995 Starcraft 17? 140hp, 3.0L I/O mercruiser.
Alpha 1 drive,
3blade aluminum, 17p prop, hydrofoil added.
1350lbs net weight.

My problem: Boating all day, with 5 people and 2 people on a tube. While going back to drop some people off, heading down stream we went through some pretty rough waters (it?s a river, but very busy,). Everything was working fine. After dropping 2 people off I was headed back upstream and while going 30mph the engine over revved up (4 people on board, heaviest to the back). I then pulled back and it stopped but lost acceleration. I then hit the gas and it was fine, then it started up again at 3500rpm. Finally after stopping 2 times I did it again and it was fine. I stopped, checked prop and it had no dings, yeah it looked sand blasted on the 2?? from end. I did not hit anything that is a fact I was in 20ft of water when this happen.

So after tilting up the engine and checking i then just decided to get home safely before I couldn't move. The whole way back I did not experience the problem. I planed fine, top end was fine, but since I did not want o get caught out there with something more serious happening I pulled the boat out. What I did notice though was a huge amount of effort to keep boat straight while planning out and even while on the plane. This was not happening before the ventilation issue. This pulling to left was not a tilt of the boat but almost as if the boat wanted to turn left, I let go of wheel at 2500RPM and it just spun fast.
This has been driving me crazy since it?s occurred so I took the prop off the drive. Nothing at all looked bad, I noticed a little push/pull play when pulling the prop and pushing it, maybe 1/16?? play. I noticed this before this happened though so I don?t expect it to be that. I put the engine in drive and i could not with all my life rotate the prop. SO that told me nothing was overly loose. I decided to put the prop back on. I am going to take the boat out tonight with just myself and a buddy with his boat incase something serious exist. So I don't know if it was a weight issue, a possible plastic bag?, a spun prop, a bad prop, or an engine coupler. (also there was no smoke, or overheating issues).

This engine has run really good, I never got any type of lost power/ventilation when turning really short. I do have a small proporsing problem that I used the hydrofoil for, but that did not exactly fix it so im going to get smart tabs. I don?t think the proposing is related to my issue. I might possibly have a bad prop all along and I am willing to buy a new prop but I just came to the boards to see if anyone had any suggestions on things before buying one.

Any help will be greatly appreciated.
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: Ventilation / Prop issue 95 starcraft 3.0L

Sounds like a random occurrence. Prop was just sucking some air with combination of rough water and the particular load and trim setting of that moment.

I wouldn't sweat it if it doesn't repeat.

When did you add the hydrofoil? Could be contributing....I do not like those products.
 

ronduth

Recruit
Joined
Jul 23, 2011
Messages
4
Re: Ventilation / Prop issue 95 starcraft 3.0L

Added it about a month ago and been out the past 4 weekends. I bought it to keep the boat from being all over the place., it helped alot but it can be a little dangerous when trimmed all the way down and moving at 25+mph.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,786
Re: Ventilation / Prop issue 95 starcraft 3.0L

it helped alot but it can be a little dangerous when trimmed all the way down and moving at 25+mph.

This condition is called "plowing" and can be very dangerous. In my book, the only time you tuck her all the way in/flaps full down is if you need it for your hole shot. Otherwise, get some air under the bow.

My 2c,

Agree on the random occurrence. Agree with your troubleshooting and results.

Mark
 
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