prop for 90 yamaha

B

bburgin

New member
Ran the boat yesterday for the first time,wondering if someone could help me with a question, I need to get my rpm up for the cruising speed I want,boat ran best around 13 to 15 mph,but the engine was only turning 3200 @ that speed,I want to get the rpm up to about 4000 to 4500 @ this speed, any one have a 22 proped like I want, and if so what pitch do you have? I understand pitch and wideopen throttle,just trying to get an idea for a prop without trying too many.
 
B Burgin,

What pitch are you currently running? 13 1/2 x 17 ?

I use a 13 1/2 x 15 on my 100 Yamaha and cruise at 4200-4400 just fine.

I don't know if that will apply to your 90 HP.

Regards, Doug Cruickshank aka Stimpys Dad
 
I don't think you really want to prop the boat for such high RPM at such a slow cruise speed. If you do, it will be easy to over rev the engine. Generally, people set up the prop so that on flat water at max speed you're at the high end of the acceptable RPM range. Then at lower speed the engine will operate (naturally) at lower RPM's - there's not a problem with that. The engine will be just fine and you'll be able to go faster when conditions permit and it's desired (e.g. to out run a storm, to get to the fish quicker, to get to the emergency room faster to get a hook removed from your finger etc).
 
What engine do you have Honda ,yamaha ,Suzuki

Most of these engines will max out at 5200-6000rpm read your manual YOU probably want a 13-14 diameter and 13-18 pitch depending on eng Read the manual go to a qualified prop shop find the right prop

I had a 90 hp Suzuki (06) on 22 cruiser we had a 14by 18 pitch propS/S the suzuki has a much bigger gear case The boat ran 34-36 mph and got almost 5mpg great prop for the cd22

Ive heard with Honda and Yamaha you needa 15-17 pitch prop check other c-brats with your motor
 
Hi BBurgin,

Check out the thread on propping my Yamaha 90:
http://www.c-brats.com/viewtopic.php?t= ... sc&start=0

At 3200 RPM you could cruise forever at 15 mph and just sip the gas. The engine is not bogging down. I agree with the other posts. Prop the boat to get max rpm at WOT around 5500-6000.

With a 13.5x15 aluminum prop my numbers are:

4500 RPM -- 24 mph*
5000 RPM -- 25-26 mph**
5500 RPM -- 26 mph**
5700 RPM -- 29 mph**
5800 RPM -- 30 mph**
WOT -- 5800 RPM

* Surprisingly comfortable;
** In general this was not comfortable, but with the bow down there was little slamming.

Later, when the water flattened out more:

4500 RPM -- 26 mph
4700 RPM -- 27 mph
4900 RPM -- 28 mph
5000 RPM -- 28-30 mph
5100 RPM -- 29-31 mph
5500 RPM -- 31-33 mph
WOT -- 5800 RPM

I think the 13.5 x 15 aluminum is the perfect prop for my use (ocean with typical 3-4' swell and 1-2' wind waves).

Enjoy the motor -- I love mine!

Matt
 
I'll put my vote of agreement here. You can easily get in the 30's with a 90 HP on a 22, and you want to run at 3200 at 15. This is more economical and easy on the engine. No risk of lugging the engine, no matter how much load you have in the C Dory 22 at this speed. The 3200 was close to what we ran in our 22. On our Tom Cat we routinely run in the low 3000 RPM range--same on my Caracal 18. Outboards do fine at higher RPM, but there is no reason to run high RPM at this low speed with a 90 hp on a C Dory 22.
 
I have a Yamaha F-90 (2005) and have used both 17 and a 15 inch props on it with my CD-22 Cruiser, and the 17 is a bit too tall, whereas a 15 is just right over a wide range of applications, weights, and conditions.

What is more, a four-blade prop will give you less vibration at low rpms, where you can sense the flutter of the blades turning.

The ~13.5" x 15"P Solas 4-blade prop can't be beat, unless you want to find an equivalent one in stainless steel.

Joe. :teeth :thup
 
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