HELP WITH PROP

[Vantoo]

Hello, I have learned a lot from you guys lately, so I am gonna ask for more help.<br />I have a 70 hp Evinrude on a 15 1/2 ft Dyna Trac bass boat. The prop that is on it now is a 13 1/4 x 15 and I get about 5900 RPM out of WOT. I have a 13 1/4 x 17 prop and wondered if it would bring my WOT rpm down to around 5500. It has a pretty good jump now and gets up pretty quick..... what ya think?????

 

[Dhadley]

Re: HELP WITH PROP

Your rpm's are just right. Why do you want to change?

 

[Rudy Brown]

Re: HELP WITH PROP

What kinda speed are you getting? Just curious.

 

[Vantoo]

Re: HELP WITH PROP

Originally posted by Dhadley:<br /> Your rpm's are just right. Why do you want to change?

DHADLEY ...Because tag on motor says should be max 5500....<br /><br />RUDY BROWN ... About 35 mph according to the gauge. Havn't used a GPS to make sure...

 

[Dhadley]

Re: HELP WITH PROP

The motor will live a lot longer, on todays fuel, set up at 5900 than it will at 5500. If it were mine I'd be playing with the set up to get the next 1000 rpm.<br /><br />If that's possible then I'd be doing more set up work to get 5900 with a 17" prop.<br /><br />Simply putting on the 17 now will cost you the holeshot and acceleration. Providing the two props are the same brand and style.

 

[Vantoo]

Re: HELP WITH PROP

Originally posted by Dhadley:<br />Simply putting on the 17 now will cost you the holeshot and acceleration. Providing the two props are the same brand and style. [/QB]

ok, thanks for the input. Maybe better off just leave it like it is? <br />So you think it better to run WOT at 5900?

 

[Dhadley]

Re: HELP WITH PROP

Your current set up -- 5900 rpm with an average load -- is fine. You can run at 3500 all day or 5900 all day. Your choice, you wont hurt a thing with that set up.<br /><br />Now, that being said -- if were mine, and you know I cant leave stuff alone, I'd use the 15" as the baseline and work with the set up to gain more. Then move to the 17 and try to get at least 5900. If you can do that obviously the efficiency will increase.<br /><br />But thats just me. Maybe that's why every boat I have has a hydraulic jackplate.....

 

[Vantoo]

Re: HELP WITH PROP

Originally posted by Dhadley:<br /> Your current set up -- 5900 rpm with an average load -- is fine. You can run at 3500 all day or 5900 all day. Your choice, you wont hurt a thing with that set up.<br /><br />Now, that being said -- if were mine, and you know I cant leave stuff alone, I'd use the 15" as the baseline and work with the set up to gain more. Then move to the 17 and try to get at least 5900. If you can do that obviously the efficiency will increase.<br /><br />But thats just me. Maybe that's why every boat I have has a hydraulic jackplate.....

thanks dhadley, I am gonna work on that and see what I come up with. Have a great one.

 

[Dhadley]

Re: HELP WITH PROP

Keep us posted. This is the fun stuff.<br /><br />Oh BTW, neat boat. The few I've worked with have responded well to set up changes.

 

[gatorred]

Re: HELP WITH PROP

I think the guy's it canada had two seventy's they turned them hard, one need's parts in powerhead lack of oil I think,the other needed the lowerunit checked more then they did it frozze up lack of gearlube my though is put oil in the gas,right way, and check gearlube more often they would have had no problem. make sure the oil injection work's to.just what i saw.