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Hello -

As the title states, we have a 1963 13' BW with a Honda BF30A pull start which I believe ways in at 150lbs and has a 17" shaft. Our top speed is only 22mph with one or two people.

I tried raising the motor up about 1.5" which is the highest it will still clamp on the transom and gained 1mph.

The boat sits nice and high in the water and it's easy to lift the bow etc. so it doesn't look water logged but hard to know for sure without weighing it.

Some other possibilities are that the hull could use a fresh sanding and paint.
And potentially a big one, I think the prop is a 9.9x10.

Any suggestions at what I should be looking at first?

Thanks so much for any help!

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Not sure what length motor you have.

Your 13' requires a 15" Short Shaft motor if the transom is original.

See this chart for motor lengths.
http://www.whalercentral.com/faq.php?...p?cat_id=7

If you are using a 20" Long Shaft then your motor is too long and dragging in the water slowing you down.

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It is clear that something is wrong. I would suggest a WOT speed of 28-30 mph.

Do you have a tach installed? If not it is very difficult to help since we don't know how fast the engine is turning.

Off hand the prop size sounds really wrong. Let me do some research.

Thread on shaft length:

http://www.whalercentral.com/forum/vi...post_81143

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What would the optimal propellor be for this era 13'? With a 40HP

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Benny -

Prop recommendations are hull, engine and hp specific.

You should open a separate thread listing the hull, engine make, model and year of engine as well as the gear ratio.

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Thank you Phil, I figured it was pretty involved. I'll get the information together.

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Thanks for the replies.

It is a Honda BF30A with a 17" shaft I believe. It has a hand pump hydraulic tilt and trim unit that I plan to add a DIY jack plate to.

Any suggestions for the prop? I was eyeing 10x13p or 10x14p 3 blade aluminum props. It is a 10 spline motor.

I do not have a tach and Honda does not make one for this motor so I plan on buying a tiny tach that uses spark plug wiring for approximate rpm range. If I manually throttle all the way with the engine cover off, I hit the rev limiter.

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See here on page 93: http://cdn.powerequipment.honda.com/m...ZV7610.pdf.

Sounds like you have a short shaft version of the motor which would be intended for a 15" transom.

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Well, I was told it was a short shaft. Got it out of the water today and grabbed the handy ole measuring tape - sure enough it's 21.7" - a long shaft.

I guess problem solved... I will be adding a jack plate.

Would still appreciate some advice for a prop on a Honda 30. Is 14 pitch overkill? Mostly running with two people, sometimes lots of gear.

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Update -

I built a jack plate onto our hydraulic tilt trim unit and got up to 23-24mph, 6200 rpm using an induction tach.

I bought a 9.9x13 prop which is only 1" up from the stock 9.9x12 and I can only reach 4700rpm, 22mph and that's with only me in the boat plus some gear.

Is it possible they manufactured a lower gear ratio version of this motor (it came from a big river raft)? Or is there something else that could be wrong with the set up?

AV plate is just out of the water at WOT. Carbs were cleaned recently and looked good.

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If you want higher speed normally higher RPM therefore you should go down not up in prop diameter as you discovered already. Although the 6200 sounds right for WOT with your original prop.
There are some guys on here that can pinpoint this much better than I can. Your OB Model/Serial number would be of big help to determine gear ratio, shaft length, etc.