Xtreme Air

I have a 1984 mistress 540's 600 plus horsepower. Just had valves and springs replaced. I am running Konrad drives and a 24 pitch bravo 1 4 blade. What speeds should i see and what kind of rpms should I be running. Engine builder said peek horsepower was between 5000 and 5600rpms. Rev limiter is set at 5800 rpms. Just curious on weather i need to downsize the prop to a 22 inch 4 blade. Boat topped out at 4950 yesterday with tabs set and drives slightly trimmed out.
Thanks for your input.

CIG3

If those motors are truely 600HP you shouldbe able to spin the 24's. Make sure you are getting full throttle when you think you are. Pull the flame arrestors and put the throttles to full. Make sure the butterflys are fully opened.

If all is well try a set of 22's but on;y as a last resort

dreamer

have a set of 22s if u need em

dreamer

http://seriousoffshore.com/forums/showthread.php?t=3575

Biggus

iTrader: (1)

They like a lot of trim. Pull the tabs up bury the throttles and keep bumping the trim button while watching the speedo. You will be surprised at how much trim it will take while still building speed.

cigrocket

iTrader: (3)

My Mistress made around 660HP. I was able to Spin 26" 4 blade Bravos to 5200RPM. I saw 73.5 with the props spinning out and around 75-76 with the props in. Good luck and enjoy the boat.

Sean

My Cafe with the same motors was also able to spin 26" Bravo I propellers. Same bottom as the Mistress.

4195

Trim it up,you need some pretty good positive trims for the Misstress and Cafe. Like said already watch the speed and as long as it increases improve your trim, you will be surprised.

Hannibal41

540s only making 600 jesus...whos your motor builder. I have 510 ci that are making 700. need a new motor guy is #1
5000-5600 u need to spin them a lot hotter then that to see anywhere near mid to high 70s 80s hate to say it but mistress hulls are no feather weights. Aronow didnt design the 35 to set world speed recs, he built them to finish in the roughest seas, and you have a wave crusher. i know i was there

you want that boat to go take weight out and play with set up toe in toe out prop size height everything. and....dont put too much gas in it....

Xtreme Air

Thanks for your input. I have had the boat for three years and had the motors built form scratch. they just went in for new valve train. Water reversion got the best of them after three years. No other damage was done . Valve and springs Guides ect. all replaced. New roller rockers and cam to replace the solid cam engine builder thought had marks on it.When I first got the engines 3 years ago top speed was 73gps @5400 rpms I did just run the boat for the first time with tabs set down about 3-4 on indicators and drive only set at 3 on indicator. I did not have a lot of time to play with it because of rain. Just thought i would have seen a little more then 4950 rpms at that position. I will need to play with the boat a little more. Just wondering what other boats of similar size and weight were seeing or if I was over propped.