Originally Posted by johnfharding

With regard to the plugs, if you have captains call I would think some exhaust is likely to still be routing through the propeller even with the thru-hull turned on. So you might go ahead and open them up all the way and see if it helps get you into the sweet spot.

Smaller diameter 4 blade vensura prop like one of the previous posters mentioned might help the RPMS come up quicker, and keep some of the mid range punch. BBlades labbing the Rev 4's may make it easier to turn them up, but would probably add RPMS up top, and you don't need that.

Thinking outside of the prop.:-)
Just a couple questions on your engine. The cam shaft is as big as you can go which would sacrifice off idle grunt up to the 2000 rpm you were talking about. This combined with the heavy boat are working against you in this application. So outside of going down some on cam size which is probably not an option. Is the carb working o.k.? Just wondered as it might be causing some off idle laziness issues as well. I guess I'm thinking along the lines of maybe its running lean, or the accelerator pumps aren't shooting enought fuel so its bogging a bit. Also is the timing set to factory specs? Also from what I have read on dyno tests for the Vortec heads, the overall timing should be no more than 34 degrees total. Just some ideas.

Originally Posted by bbladesprops

I just thought I'd through out some history.
Vensura was the original large hub Trophy (pre Plus).... Remember that? Boy do I.............. and the repercussions.

Then it was the ? Who can answer that question?

Now it is the Vensura.

I'll tell you more if you can get the second question correct.

The Vengeance is a nicely named QS thicker with HiPolish finish.
I kind of like the Rev4 too (depending on your goals). Down pitch to get your engine to the top of the R range for the engine. This will not hurt the drive and give the boat all around performance.

Brett

Originally Posted by A.O. Razor

That was called the Offshore. Sometimes the Vensura is still called the Offshore series. What do I get

Originally Posted by bbladesprops

Not sure what you mean. Look back3 posts.

Brett

By the way, it isn't supposed to be refered to as the OS series any more. Merc likes the new marketing aspect as being a fresh item..........

Originally Posted by donzi matt

Thanks for the input John! I spoke with Brett at BBlades and he is sending me a Rev 4 to try without the plugs. His thought is even if I have no exhaust through the hub, the negative pressure at take off will still pull air and possibly give me the results I am looking for. He feels the Rev 4 is probably the best bet for the boat, and if need be labbing could be done to increase performance without changing top RPM.

As for the motor, I am running a 600CFM holley. The motor feels like it is pulling fine, and I have brought the jetting on the primaries from 67's to 69's with no change off the line. I have 70's I may try also, but if those don't change anything than I think I can rule out the carb. The motor feels just fine, with no lean sags or stumbles to it. I do think the cam is on the big side though. I chose it because I was afraid the larger torque on the XM-264 would be more likely to hurt the Alpha than the XM-270's torque which occurs a little higher up the powerband. I have total timing set for 30 degrees at full advance, as suggested by BobL.

I think a little slippage might help get me up into the best spot in the powerband, and make the boat feel totally different on launch.