Prop Loses Power On Tight Turn

[DonnyC2]

Hey all!


I have a 2004 16.5 foot boat and Mercury 50hp 2 stroke motor of the same year.

I have had my boat for 9 years and have always had the issue that if I take a super tight turn I lose power until I straighten out a bit.

The prop is the original prop, and I heard somewhere that if I replaced the prop with a stainless steel one the issue would go away. Is this correct, why?

 

[flyingscott]

Normal for the motor to do that. Forcing a boat into a turn is like driving a car uphill, it is losing power until it levels out. You can correct it by giving it more gas but if you are floored then that's what it does.

 

[jimmbo]

Is the engine speeding up but the boat slows down?

 

[DonnyC2]

That occurs only when at full throttle, or mostly full throttle.

 

[Grub54891]

Had the same issue with a 50 Evinrude. Went down 2 deg in pitch, got the wot rpm's to where the needed to be, cornering was no longer an issue.

 

[Texasmark]

Hey all!


I have a 2004 16.5 foot boat and Mercury 50hp 2 stroke motor of the same year.

I have had my boat for 9 years and have always had the issue that if I take a super tight turn I lose power until I straighten out a bit.

The prop is the original prop, and I heard somewhere that if I replaced the prop with a stainless steel one the issue would go away. Is this correct, why?

If you have any kind of keel (which aluminum boats usually have, some glass and wood always, in a tight turn it causes cavitation bubbles in front of the lower unit. Besides that the lower unit itself is pushing water out on the side leading into the turn causing a source for more cavitation bubbles. Next if you are running your engine high on the transom, and/or tilted out....the more the worse it is, that puts the prop near the surface where it ca suck air since it's easier to suck in air near the surface.

A Turning Point Hustler is built to take care of that problem. They sell them on here....need to get the hub kit recommended with the prop. ad. If your current prop is running fine otherwise, you might start with the same pitch within your 10+" (assumed current) diameter...New listings may be off a fraction of an inch on diameter but that varies with the design of different props.

 

[flyingscott]

There is no magic prop to fix that. Every V-hull i have owned has done that. Forcing a boat into a hard turn takes power the faster you are going, the harder it is to pull out of it. I have never had a keeled boat put cavitation bubbles into my prop, And I think somebody owns stock in turning point.. You are borderline on power for that boat. Get a bigger motor or live with what you have.

 

[Texasmark]

There is no magic prop to fix that. Every V-hull i have owned has done that. Forcing a boat into a hard turn takes power the faster you are going, the harder it is to pull out of it. I have never had a keeled boat put cavitation bubbles into my prop, And I think somebody owns stock in turning point.. You are borderline on power for that boat. Get a bigger motor or live with what you have.

Putting this into G rated words, you need to do some homework before you run your mouth!

 

[Grub54891]

You are borderline on power for that boat. Get a bigger motor or live with what you have. ​

That statement is true. I knew I needed a bigger motor also. I did get going pretty good by re-propping but it could have been better with a proper motor.

 

[flyingscott]

Putting this into G rated words, you need to do some homework before you run your mouth!

You are correct my mistake. I forgot 2 strk outboards make no torque and turning point props turn 2 strks into diesels.

 

[jimmbo]

You are correct my mistake. I forgot 2 strk outboards make no torque and turning point props turn 2 strks into diesels.

Naw, 2 Stroke Gas engines at least have a Sweet Smelling Smoke, unlike the Carcinogenic Exhaust of Diesels

 

[WesNewell]

When you make a tight turn the engine angle changes and puts the prop closer to the water surface on 99% of boats. In most cases this can only be cured by either trimming the engine down or lowering the engine mounting height or a combo of both. Both trimming down and/or lowering the mounting will usually add more drag causing a loss orf top speed

 

[DonnyC2]

There is no magic prop to fix that. Every V-hull i have owned has done that. Forcing a boat into a hard turn takes power the faster you are going, the harder it is to pull out of it. I have never had a keeled boat put cavitation bubbles into my prop, And I think somebody owns stock in turning point.. You are borderline on power for that boat. Get a bigger motor or live with what you have.

It is only rated for 60hp, so I don't think that extra 10hph would make a ton of difference, would it?

 

[flyingscott]

No it would not so it is what it is. It is not uncommon, I have a 70 hp Evinrude on my SS160 and if I throw it into a hard turn it pulls the RPMs down.

 

[jimmbo]

Every boat I have owned has slowed down a bit in turns. Some have had the prop suck air and lose its bite, others just lost between 3 and 6 mph. A couple, you didn't even try to turn when Trimmed out at WOT