It's getting there.

[Jay Martin]

Yamaha motor mounting issue..Hummm! Not sure! What are you trying to say??? Yamaha setup on an Allison is not common. All I can say is Yamaha's are heavy vs. the Mercs so the 12-14inch setback is not needed. I did not measure the height with the spacers, they are gone now. Todd at Hydromotive says the quad 4 o/t should be running at 1/4 below and 1/4-3/8 above is getting in the danger zone. Yesterday I was between 1/4 and even with the 89.97 run.

Keep in mind the load I'm carrying, there is at lest 150-175 lbs in the front stoage on the front deck, full tank of gas, batterys (group 27) big trolling motor up front.

The guy I bought the boat from was running a 97 merc 225 promax, he said his best was about 92.

 

[Allyfishing]

Today (2-07-10) I test ran A Turbo TXP o/t4 28p, I ran this prop last weekend while it was still in stock form.Stock it ran 85.41 mph/gps at 5900-6000 rpm.

Only tested the Hydro's today...

Water was slick as glass today while testing the Hydromotive Quad IV o/t 27 and 28 pitch propellers.

I ran the 27p first and here are the results.

Hydromotive Quad IV o/t 27, 87.49 mph/gps @ 6500 rpm's, could have turned more rpm's but I was already over my limit.

Hydromotive Quad IV o/t 28, 89.97 mph/gps @ 6400 rpm's, she was maxed out as far as the engine height. I still have about an inch left to raise her up but ran out of lift because of height also.

Next I will play with some more set back. I will be adding my Bobs machine shop two inch spacers for a total of 12.5 inchs.
__________________

The top statement is from your first test runs with the TXP. The RPM's are what jumped out at me for the same pitch props. Now granted a TXP and a Hydro are 2 different animals but why such drastic differences in RPM's?? What should your Yammi turn? And only 4.5 MPH difference. Depending on how the holes are drilled in the spacer plates and how its made it probable put you lower deeper in the water. That happened to me when I put spacers on from CMC on my old boat. I had to fllip them over and use a pettern to drill new holes so the spacers made the JP higher on the spacer plates. Make sense? Just a thought if I understand you right. Anyway, sound pretty good!! Ain't it fun?? :big grin:big grin

 

[chad202]

Jay, Todd is correct for a boat with stock lip. Yours is not. But ur the one who must understand what the boat is telling you. I personally drove that boat before u got it 95mph. It was a 12" plate, an inch or so above.

 

[Jay Martin]

I told Todd about the lip, thats when he told me about the 1/4-3/8 above.
Yea I realize what happen when I installed the spacers, the motor was all the way up on the last hole, just can't make it go any higher, there's no way with what I have.

The Turbo TXP's run taller than most props, that 28 is more like a 29 1/2. That 85 mph run was bone stock, they run so much better when they are sharpened up and balanced.

Chad, what prop was he running on this boat?

 

[chad202]

A 30 performer et cut down to 14.5". Speeds were with troller and all fishing equip.

 

[Jay Martin]

Ahh!! Thats the ticket, the over hub will be faster than the o/t, I'll stick with the o/t for now.
What rpm was he turning it?
I would like to try one out someday.

 

[chad202]

I think it was around 6600-6800 if I remember right.

 

[Jay Martin]

Without a dought thats the extra 5mph over what I'm running.
6200-6400 is the range I need to stay in.
Hydrotec said 6500 is redline but the engine starts droping off at 6400.
400-500 rpms makes a big difference on top end.
I'm happy with what I have....For Now...:wink..:at the bar...

 

[chad202]

Good deal Jay.

 

[F2008]

Yamaha motor mounting issue..Hummm! Not sure! What are you trying to say???

I'm not familiar with Yamaha so I was curious about the location of the mounting holes and such and why the motor couldn't be raised higher on the jackplate.

 

[Jay Martin]

It's basicly the same as the mercs. Its all the way up...