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Don't under estimate the two cylinder

Haha so ive heard. Saw in the T750/T850 thread Hounddog has going. The T750 boats are into the low 60's now, thats very impressive for a 2 cylinder!

Guys in Australia with ported 49ci's run both the 15:28 and 12:29 gears in the nitro boxes. The 15:28 run 12X23 in props and the 12:29 run 12X25 in props and both rev between 7,000 and 7,500 rpm depending on prop setup. I can not give you an accurate speed but I have been told that it ranges from the low to mid 70MPH range. A modified 49ci can rev extremely high as this engine was the basis for the FT19s and Mod 50 race engine. These engines with the straight fronts and dual carbs use to rev between 7,500 to 8,500 rpm without any issues. Stock 49ci should be ported to FT19s specs. The 12:29 with the 12X25 in prop is more suited to short courses while the 15:28 with the 12X23in is more suited to long courses.

Stephen Medaris

13Checkmate I've been using a big case with a bobs cone w/low water pick up on my Voodoo for a couple of years now (89 56ci long shaft, stock with CCM reeds and 68 mains to make sure it didn't have any lean spots). I'm using a Ron hill 13.5 x 26 Yamaha drag copy, my rpm is in the 6500 range and I'm 1/2" below the pad at 58 gps. I can go higher on transom height as I have 30 psi at wot but it's starting to crab (going to try a torque tab).
I think the case is a big factor in limiting the top speed, ie: big pitch vs speed allows the prop to want to pull the boat side ways vs ahead and efficiency goes out the window. I'd like to hear what suggestions some of the racers think might work for the big cases (I kept mine as its way easier to get parts if I break it).

My steering gets tighter as i go faster but its still easy to manage. It would start to pull to the right if you loosen the grip on the steering wheel. Probably gonna try a torque tab soon

Have you tried raising the motor more ? We don't run diameters like that but on our 12.5 we find it handles better higher up when we're on the trim.

Guys run the big 90 Yamaha case fast so I don't see why you couldn't pick up a bunch more speed. Might have to do some prop work.

Where around Kingston are you again I think I asked before, we have a family cottage north of Napanee

I live in Kingston and my cottage is on Big Gull., I did come to see you guys run at Beaver lake (great event), Hydroid had give me a few tips when I spoke to him there. I haven't went any higher, guess there's nothing to lose lol. The boat handles pretty darn good now, it's set up pretty light for a "cottage" boat, nothing extra in the boat, new floor and transom, hydraulic steering, oddesy 625 battery and a 5.5 jack plate. I know I could swing more pitch if I had one as it turns this no problem. Any suggestions on what prop work could be done? I was going to send it to Kawartha in the fall.

Im looking for a prop similar to yours right now BigGull, need a 26+ pitch 12-13" diameter prop. I need to go up higher for sure, thatll let me swing a cleaver nicely. Id love to try a 26 pitch raker, anyone know if omc made a 26 pitch raker for the v4?

Sorry we missed you at the race could have come over for a bite to eat after the races with some of the other guys

Lwp...I'd be jacking it a 1/4" at a time and see what happens, once you get to that sweet spot you can decrease the increments of movement.

I think in both your cases I'd be propping to turn in the 7100-7200 area.

The 26 might actually be too much pitch but you should pick up some more rpm when you raise the motor.

Will try that for sure, thanks for the advice. Ps: it's great fun watching some of the faces when you pass their $60 k plus boat lol.