WOT RPM's on my 98 Merc. 40hp

[tmanis0182]

Okay, so Saturday was the maiden voyage for my re-powered 17 foot 1985 Bass Tracker. I put a 1998 Mercury 40hp 2-stroke 3 cy. ELPTO on it with a new Turning Point 10 3/4" x 12p prop(nice holeshot). I know the motors rpm range is rated at 5000-5500 rpms and I was running at 5200 rpms at WOT. My question is... should I be satisfied with this? Or can I squeeze a little more out of it with a different prop and if so, any recommendations to either the diameter or pitch changes.

 

[trendsetter240]

Re: WOT RPM's on my 98 Merc. 40hp

Okay, so Saturday was the maiden voyage for my re-powered 17 foot 1985 Bass Tracker. I put a 1998 Mercury 40hp 2-stroke 3 cy. ELPTO on it with a new Turning Point 10 3/4" x 12p prop(nice holeshot). I know the motors rpm range is rated at 5000-5500 rpms and I was running at 5200 rpms at WOT. My question is... should I be satisfied with this? Or can I squeeze a little more out of it with a different prop and if so, any recommendations to either the diameter or pitch changes.

Depends if you can get good ethanol free gas or not. If you have to burn ethanol blended gas then you should aim for another few hundred RPM at WOT. The same prop in an 11p would get you close or a solas amita in 12p if is its available for your motor.

I'm not sure if an 11p 4blade would be the right fit, if you provide more specific details as found in hwsiii's form you can get a more accurate answer.

Cheers

 

[tmanis0182]

Re: WOT RPM's on my 98 Merc. 40hp

Well, right now all the gas stations around me sell 10% ethanol gas. Actually the sole purpose of me buying a Turning Point Hustler was so I had a some what inexpensive option if the prop size and/or pitch were not right. $53.00 is better than $100 or $150...

 

[steelespike]

Re: WOT RPM's on my 98 Merc. 40hp

At $53 I would try the next size down.They usually recommend propping in the high end of the rated range.Two reasons ,works better with todays gas and allows the motor to stay in higher rpm with a load.
You also may want to be sure the motor is mounted as high as it can go without
venting(cavitation) problems.The Turning point will allow maximum height.

 

[tmanis0182]

Re: WOT RPM's on my 98 Merc. 40hp

Thanks steelespike. Would you recommend going down in diameter, say to 10 1/2" or 10 3/8", or to an 11 pitch?

 

[steelespike]

Re: WOT RPM's on my 98 Merc. 40hp

If your doing a Turningpoint Hustler I believe there is only one diameter.
Don't even look at diameter;diameter simply follows the design.
Diameter is only considered for certain specific problems.
If you have a Hustler replace with Hustler to get predictable results.