engine rpm to low

[xltier]

i have a 21 ft.1997 maxum cuddy with a 5.7 4 barrell.i have a 14.25x21 prop on it now.top speed 40mph at 3400 rpm.you can pull the throttle back almost 1/2 way without any speed loss at top speed.trimming the drive will gain about 300 rpm and about 3 mph.cant trim much or it loses grip.is there a better prop for this application. thanks to all.have a great weekend

 

[Bifflefan]

Re: engine rpm to low

Sounds like you are over proped. A 19p should do a little better. You just dont have the horse power to push a 21p. You may not go any faster, but the hole shot will be better and you should have better throttle response at higher RPMs.
As far as better props, you can talk until the end of time on that subject.
I like a 4 blade alum or SS. My alum gets beaten up because the lake I fish on has a lot of sticks and stuff in it, a SS wont get dinged up as bad but also wont be a failure point if you hit something hard.
4 blades steer better at low speed and dont loose grip as much, 3 blades go faster and are cheaper.
Hope thats not to much at one shot.

 

[steelespike]

Re: engine rpm to low

If my info is right you have to make up about 1400 rpm.
I think you should check the tach before any changes

 

[xltier]

Re: engine rpm to low

will do,thanks

 

[xltier]

Re: engine rpm to low

perfect thanks. ill consider after checking gauge.

 

[craze1cars]

Re: engine rpm to low

.you can pull the throttle back almost 1/2 way without any speed loss at top speed.

This is a big red flag for me. Is your throttle plate even opening fully at WOT?