help, small boat won't plane

[tricolour]

I've got a lightweight 12foot aluminum boat that won't plane anymore. What's strange is that it used to, both with a 5.5 and johnson 10hp that I currently use.

The bow stays low and plows through the water. I've tilted the motor back as far as it can go, and that forces it to plane eventually, but the bow still stays low, and I cannot go at top speed because of it. My engine runs perfectly and the boat is rated for 10hp. I am not carrying any weight up front. What happened and how can I fix this? I used to be able to do 18mph max when the bow was up like it should be.

 

[oops!]

Re: help, small boat won't plane

hi tri......welcome to i boats !

your trim is out of adjustment.

the motor is forcing the bow into the water....move the trim pins.

 

[Bob's Garage]

Re: help, small boat won't plane

hi tri......welcome to i boats !

your trim is out of adjustment.

the motor is forcing the bow into the water....move the trim pins.

He did.

Don't know much about the situation but I am going to assume that this is a typical aluminum boat; no liner, bench seats (possibly wood, are these enclosed, with foam which may be wet), with a wood plate on the transom. So very unlikely that there is a problem with weight from water intrusion.

So, having said this there are 2 possibilities left;

Either the engine has lost some power - do a compression test, check rpm, whatever can be done for a small engine to check performance.

Or - go on a diet, we almost all gain weight as we get older.

 

[Downwindtracker2]

Re: help, small boat won't plane

My 12' just gets up on plane on calm water with a very good 7.5 merc,but I have to move forward.

 

[Bondo]

Re: help, small boat won't plane

I've got a lightweight 12foot aluminum boat that won't plane anymore. What's strange is that it used to, both with a 5.5 and johnson 10hp that I currently use.

The bow stays low and plows through the water. I've tilted the motor back as far as it can go, and that forces it to plane eventually, but the bow still stays low, and I cannot go at top speed because of it. My engine runs perfectly and the boat is rated for 10hp. I am not carrying any weight up front. What happened and how can I fix this? I used to be able to do 18mph max when the bow was up like it should be.

Ayuh,.... Are there any Dents in the bottom,..??

 

[rbh]

Re: help, small boat won't plane

Could the foam be water logged???

 

[Captain Caveman]

Re: help, small boat won't plane

My first thought was loss of motor power as well.

Could be sludge on the bottom of the hull. Try giving it a good wash.

 

[5150abf]

Re: help, small boat won't plane

"Tilted the motor as far back as it will go" you moved the prop away from the hull yes, that should correct the problem.

As others said I would suspect the engine lost some power, if a jet in one carb is a little clogged it would lose power.

If it used to plane and doesn't now and you haven't cheanged anything that leaves few posabilities other than being down on power

 

[kenmyfam]

Re: help, small boat won't plane

Trim all the way out and if no improvement with the bow popping up check the motor for
Compression
Spark
Fuel delivery.
How do the plugs look ???

 

[Frank Acampora]

Re: help, small boat won't plane

Listen to Bondo: Check for a "hook" in the bottom back near the transom.

 

[cr2k]

Re: help, small boat won't plane

It's your prop man, all those little dings have added up.