Need prop help

[hassm]

I am running an F115 on a 19' Sea Hunt Navigator and only getting 22-23 MPH. Something is wrong. If you are getting better speed, please tell me what prop you are using. Mine is the stock prop from Yam factory. Thanks

[chuck34]

What RPM's are you running at WOT?

Have you tried trimming out the engine.

Is this a new boat? If new, have you asked your dealer about it?

If it's a used boat, did it run like this when you sea trialed before buying from the previous owner?

[hassm]

It has always run this way. I just now saw the specs on the Yam website and was crushed!

Edited July 26, 2009 by Marsha

[chuck34]

Back to my first post...

What RPM's are you running at WOT?

Have you tried trimming out the engine.

Is this a new boat? If new, have you asked your dealer about it?

If it's a used boat, did it run like this when you sea trialed before buying from the previous owner?

You need help but if you don't answer our questions, we can't give you any advice.

Edited July 26, 2009 by chuck34

[jack14]

From what you posted, I assume you looked at the Yamaha Performance Bulletin for your boat and motor. In the bulletin they show the prop type and size they tested with. Yamaha tests with props that produce optimum performance. You should be running the same one.

[chuck34]

How are you getting your speed? Speedometer or GPS?

[ken2]

Here is the performance report from yamaha. http://www.yamaha-motor.com/assets/product...2-152-SHB-B.pdf

They are running a Michigan Wheel Apollo.

There is no such thing as "the stock yamaha prop" Yamaha makes lots of props, and depending what the engine gets bolted to, changes what prop they put on the motor.

The Dealer is normally who puts the prop on there anyways, and they don't always get the right one.

If you answer the questions above to the best of your knowledge, everyone can help you out.

RPM at wide open throttle?

are you trimming the motor?

what prop do you have currently?

what hole is your motor mounted in?

How many people are on the boat when it only does 28 mph?

How are you measuring speed, GPS or Speedometer?

They are all important to figuring out what your problem is. Or if you have a problem at all.

Edited July 27, 2009 by ken2