h17 setup ?

[tinfox42]

i have a 97 h51 with, (1995) 85 hp Yamaha 4 inch jackplate with 8 ft gen 1 talon coming off a bracket attached to the jackplate
i am running a turbo 13 1/4 x 17 ss prop and have it set 5.25 " below the pad, i have 3 battery's in back, my hole shot is very bad, and when trimmed up i can reach about 44 ish mph (speedo) but it porpoises preety bad

so should i raise the motor up due to extra weight in the back?
hydrofoil? (motor is already drilled for it)
or deal with going 39 trimmed down and no porpoising?

thank you

[Ranger391v]

Message 'Xpress Spanky'. He had/has a very similar rig and I think he would be able to help you.

Turbo 1 prop in a 17" was a very popular recommendation of his for H51's w/Yamaha 90's (same motor as your older version 85horse). He can also point you in the right direction on prop shaft height. With that said, 5.25" is really-really low.

Have you checked the bottom of any dents or hooks (concave area) in the hull ..... especially with this being an older boat. You could have them from the boat hitting stumps,etc ...... as well as check the back of the boat where the bunk boards end, especially if the bunk boards do not extend past the transom. Not uncommon for 'short' bunk boards to beat a hook into a hull right there.

If you have access to a 17" Trophy Plus, you might trying it. My H50 (16' version) had the same motor on it that you got ..... and it liked the 17" Trophy the best.

Good Luck. Hope that helps some.

[tinfox42]

Thank s for the reply I am going to move the motor up to 4.25 and c what's happens, only problem is I know need some warm weather to try it out
thanks

[Ranger391v]

I think that would be a good move. I can't remember where exactly mine liked it the best ........ I just remembered it was a compromise between 'good handling mannors' or 'highest top end' ........ the 2 prop shaft heights never coexisted. That's the main reason a lot of guys run hydraulic jackplates on hyperlifts.

Good Luck!

[JigALow]

I have a similar rig, it's a 02' X54 with a Yamaha 90 running a 12" jackplate, I don't have a talon or power pole, and only run two batteries. But, my boat runs best at 3.5" pad to prop, and tops out at 47mph gps.

Be sure you have a water pressure gauge if you going to raise the motor much.

[tinfox42]

I do not have a water pressure gauge , is a water pressure gauge a must ?
the. BAck of my boat does sit pretty low in the water , I just moved my motor up to 4" , I ha e not got a chance to try it out due to ice on the lakes

[Dbnaileng]

I wouldn't own a boat without one.

[tinfox42]

Just ordered one I will post an update after I get the boat out

thanks

[JigALow]

I think 14-15psi is the no go below mark, I could raise my motor a little more and get more mph, but I lose water pressure.

Im also running a Turbo1 prop 17 pitch.

[tinfox42]

I have the motor set at 4" any higher I lose water pressure, still proposing pretty bad when try to trim up
any ideas , move batteries to the front?
Hydrofoil ?
diff prop?
with trimmed down I go 35 mph with trimmed up I can get 45 mph (gps) but bounces bad
i do not want to use trim tabs because I fish some weedy stumpy lakes and they would not last long I expect
any help would be appreciated
thanks

[Mocatt]

I have a 03 H51 with a 90hp Mercury on the back. I only have 2 batteries but, they are group 31 Odesseys and they weigh about 80lbs each and no power poles. With a full tank of gas and a average amount tackle I have hit 48mph gps with just me (230lbs) in the boat. I have almost no bow rise when coming out of the hole and no porpoising. Not sure on my engine height but, I will check it and let you know. I'm running a 17 pitch Power Tech prop.

[tinfox42]

I was told today from a company that sells props that the turbo 1 prop is a bow rise prop and I need a stern ride prop like a power tech 13 1/4x17
i do not know much about props does that sound right ?

[Mocatt]

That's what I'm running on my H51.

[Ranger391v]

My H50 with the same motor porpoised pretty badly as well ......... until I ran the Trophy Plus prop.

Prop slip is a combination of things, but regardless it's the prop biting and then losing bite that causes the bounce. A 4 blade prop like the Trophy cures what ails a lot of Xpress hyperlift boats.

With that said, I DEFINITELY would not buy a Powertech prop for the small gearcase size motors on the hyperlift hull. Turbo 1 was a great prop for a long time by many with the H50/H51 boats with Yamaha 75/90 motors ........ but many who have ran the Trophy seem to like it the best. Keep in mind if you shop for one, that the Trophy Sport and the Trophy Plus are 2 totally different props ....... the 'Sport' is meant for 40/50/60 size gearcases.

Good Luck.

[fishingram24]

The porpoising problem can be eliminated by having a weld bead put on the very aft and bottom of the transom. May be the only solution. Newer models already have it on them. Bought a new X54 in 2001 and took it back the dealer a week after I bought it to have this done. We had discussed the possibility prior to buying it as it was an issue on some boats at the time. My 2012 X17 came with this already done.

[tinfox42]

I put a buddy hydrofoil on it today and it did not help, I had him sit on the front and it did not help , I do weld aluminum, so that will be the next step ,
thank u I will update u after I weld it and take it out

[tinfox42]

Aright the saga continues , I welded a 3" by 1/4 bead on the very back , outer most of the hull , the bead is welded down if the boat is in the water , it did not help I am able to go 38 mph at 4900 rpm as soon as I trim up alittle the boat porpoises bad and the high I can get my rpm is 5200 when proposing and 42 mph , when I am turning right or left it does not porpoise,any suggestions , next step is a new prop
thanks