It's Not Enough. The Noble Quest for more speed

[snowmanmtl]

My Mirage now flys straight and true( except between 50 and 65) with my 5 inches of set back. But I seem to have hit an invisible wall at 85 mph. Actually, both boats I'm running won't get over this barrier. What is my next step in this noblest of Quests. Here are my two setups:
1. 94 Mirage Jaguar ( with a ski bottom I'm told) 93 Merc ( 2.5)carb( WHM) Alum. Flywheel, 16 amp stator, Heads Shaved ( .045) to 35cc, 4 petal rubber cages with boyesen reeds, relieved exhaust, drystacked,oiler removed, will be installing an electric fuel pump. Compression is 128 to 130 lbs. Turning a 30 Hoss at 6000 rpms to a max. speed of 84.2 mph gps. May put back the 9 1/2 inch setback. Should I take anothe .015 off the heads or should I be tearing the motor apart? Anything else I could do?
2. 86 Mirage Sprint with 81 225 2.4 ( 25hrs since rebuild I was told) 5 inches of setback,elect. fuel pump,wh 20 carbs intake have been drilled, 7 petal boyesen reeds, heads are stamped .060, exhaust relieved. Compression is 125 . Turning a 30 chopper 6000 to roughly 85 mph ( not gps ed yet). What can I do here?
Just bought a 32P Yamaha from Dark Allison which I will try on both.
What should I be doing to get more poop from these motors? Are they tired or is that the best fishing motors can do ?
Should I be looking for a 260?

[snowmanmtl]

and I guess I'll have to go shopping for an 150 Evinrude Ficht. Worked for him. Guess these Black motors just can't cut it anymore :eek:

[vector mike]

I think you need to reconsider your way of thinking before you regret doing something like going to a "White Mota". :D

[O/B Dude]

I am assuming you have a 2.5 200? Even a 200 should run in the 90's. I know Hoss Tritons dont work well on many tunnels. (Great on Allisons though) Something isnt right. Either a hook in the bottom or your motor isnt up to par. High speed windings on the stator maybe? Have you done the small prop test? Put a really low pitch prop on it and see if it falls on its face at around 6000. If so, you know there is a problem there.

As for the 81 2.4 225, 85 mph is about right on that hull. There's a bit more left that you can get out of it, but those motors arent as potent as a 2.5.

You need a cleaver or an ET. The Yamaha props are great up to 26 pitch but I find that more pitch than that doesnt work well with that type of blade design. Try it...might work great...you never know. But definitely get a small prop and try it on the 2.5. Something like an aluminum 21 pitch would be a good test prop.
OBD

[patchesII]

two things. make sure you don't have a check ball valve coming out of the tank and restricting fuel flow and get an electric pump on that thing. O/B Dude is right, that motor should turn more than 6000

[snowmanmtl]

Followed up on the 2.5 stuff. Picked up a chopper 22 but, didn't try it. Put in the fuel pump, bypassing the stock. Actually removed it completely and plugged the holes. Clear fuel filter to a Mallory pump then to a water separator/fuel filter to the carbs. No fuel pressure reg.. Works well. Put on a 14 X 28 Cleaver and had it turning in the 6700 range( Tach is Bouncing). Unfortunately, I couldn't really get a chance to run it long enough to get to top speed. Gps was over 77 but it was a little flighty with the smaller prop. As well, there is a dead spot before the end of the peddle. Is there something electrical stopping me now or is it a carb adjustment. Going to put the Hoss Back on and see what happens. I'm off the Ficht Idea for now, it's still black.

[O/B Dude]

The rule is to make changes 1 at a time. You now know it will spin over 6000 but you dont know if it was the prop, the pump, or both. You need to run it with the triton now and see what happens. You also need to find out how much fuel pressure you have. Should be 5-7 at WOT. Over 7 or so and it may blow the needles off the seats and flood. Under 5 and it may run lean.

[snowmanmtl]

are right. Get a little ahead of myself at times, been lucky so far, I guess. Got lucky in a way again,fuel pump died ( it was a through in)before next run with the Hoss. Will make sure I have fuel pressure guage with next pump. Off to the " buy and sell forums " I will go.