Set Up Help 11' Tunnel

[MN1]

Wow 7300!! That puts you close to 60mph.....how hard can you run the engine before it disintegrate?? At 7300rpm you are at least 25% above the recommended operating range!

Actually, we saw 63 mph with the boat setup for competition on the gps.
Also on the transom height, it is the center of the prop shaft that is 5/8" above the bottom with the boat trimmed at 3 degrees. Remember, the farther the motor is setback off the transom the higher it has to go to be the same height in the water when the boat trims. I use AutoCad to find this dimension.
Mark N

[Infoless Racer]

Mark do you have exhaust relief vents on your lower unit? What other mods were done to get the engine howling at the rpm?? thanks

[MN1]

Sport c is a stock class, so no extra holes and stock motor cover. Stock all the way!
Mark N

[JohnsonM50]

[QUOTE=Infoless Racer;85012]Mark do you have exhaust relief vents on your lower unit? What other mods were done to get the engine howling at the rpm?? thanks
The motor will likely turn pretty good Rs no problem stock, .. if prop, set up & tuning are close or optimal.. pretty fast

[Infoless Racer]

noted....this is going to be fun. Will keep my engine stock and see how far i can push the hull. Thanks guys

[JohnsonM50]

[QUOTE=Infoless Racer;85025]noted....this is going to be fun. Will keep my engine stock and see how far i can push the hull. Thanks guys


Thats what Id do 1st, run what you have & get used to it as you get more from it. Ill bet its an animal accelerating! Relief holes may have a negative effect.. but sound cool [like the Cheery Bomb slogan.. " disturbing the peace since 1976"]

[moomba]

What RPM's will my 60HP Evinrude twin turn without hurting it??

[MN1]

What RPM's will my 60HP Evinrude twin turn without hurting it??

It should be able to turn 6500 to 7000 with no problem. It is basically the same as a SST 45 powerhead.
Mark N

[moomba]

It should be able to turn 6500 to 7000 with no problem. It is basically the same as a SST 45 powerhead.
Mark N

I need to get a manual for this motor. What should I run the timing at at wide open throttle. I run 25 Deg BTDC advanced on all my v6 Mercs with all the advance boxes in the garbage can. Am I going to need to do any jet changing to run the extra RPM's ??
Thanks
Steve

[MN1]

I don't have an answer on the timing. But Ron Hill or one of the SST 45 racers should know. On the jetting, most motors come from the factory jetted a little rich. Keep it stock for testing props and boat setup. Then adjust if needed later. The SST 45 guys will be your best source for motor tuning.
Mark N