Jack plate installed...

[strat250]

Ok, so I installed the jack plate. Its a TH Marine HiJacker.
I have it set almost right at the top, and the motor is also on the top hole, and I am sitting at 3.5" below the pad. Is it normal to have to raise it so high?

Also as a side note, how much rpm's do you think I will gain or lose by doing this?

I was sitting at 5400rpms at WOT with a 17 Pitch 3 blade Aluminum prop, powered by a 70 johnson, on a 15.6 foot stratos 250

At the time I was sitting at 5.5 inches below the pad.


Take your guess. I should be able to get it in the water tomorow morning for a test run.

[hulapopr]

with that aluminum prop it may porpoise bad.probably need to go to a stainless prop to get better performance.

[strat250]

RPM's went up to 5700, no porpusing, although I don't think the prop is giving enough bow lift, and I don't think it likes to be run so high, as it will ventillate on any type of corner. I have a 4 blade alluminum that is supposed to be run higher, so we will see how it works, supposed to be delivered this week sometime.
MPH went up as well by 3 mph, to 36mph, prop lsip has remained relativly the same. If i continue to trim it the prop ventilates, and it doesn't seem like the bow is up high enough.
I am still not too sure why the guy I ordered the prop from said an SS prop will be worse out of the hole.

[lkhartwl]

if you are trying to turn at WOT you need to trim down as not to cavitate, or you can blow your power head, remember when your prop is not in the water neither are your water inlets. as for bow lift you NEED a SS prop, alum props are not made for bow lift and such and can deform since alum is softer than SS. also whomever is doing the set up for you needs to reread the manual on props. SS are made for hole shots and lift for the most part, you may also gain 1-2 mph but I doubt it since you are only running a 70 hp motor.

[strat250]

I alays thought SS props gave better hole shot, but this guy said since the SS props are stiffer, the aluminum prop will flex and de pitch it and give better hole shot than the SS prop.

[strat250]

What prop would you recomend? I was thinking of getting an 18 pitch raker, and if its just too much pitch I could send it to Mark to get blue printed and 1 inch taken off?

[lkhartwl]

talk to a dealer in your area and see if he has a used one to try before you buy or look in the props for sale section of the forums there is on the main page a listing on the left for props and a special section for ones that are smaller pitch.