Proper 454 Mag RPM Range?
 

I am running a 454 Mag in my 240 sport with a Bravo One drive. I want to say its a 1.50 to 1 ratio on the drive. (I swear I read that on it somewhere) The prop I am using is a 23pitch Mirage. I also have a 23p Clever prop too. What RPM range should I reach at WOT?

I seem to remember hitting around the 5 K mark when I first got the boat. Now it seams like it hits closer to 4800. Could I have lost RPMs somewhere? The only thing I've done on the motor is to rebuild the raw water pump internals after the original impeller siezed up and toasted the belts. I did have the Gimbal bearings replaced too. Also, The flame arrestor was pretty dirty at the end of the season. Cleaned that completely when I winterized it. So no idea what effect that will have as of now. Thanks for any input.

Re: Proper 454 Mag RPM Range?
 

4600-5000 you lost rpm but did you lose speed? Maybe the tach is getting goofy.

Re: Proper 454 Mag RPM Range?
 

Couldnt tell you about the speed. The speedo rarely works. When it does, not sure how accurate it is in the first place. It runs off the mechanicals in the drive. I did run a GPS once and was topping out about 58 59 mph with 1/4 tank, me and 1 passenger. Im just wondering how much the flame arrestor was affecting it. It was pretty bad. Had to be choking off a fare amount of air.

Re: Proper 454 Mag RPM Range?
 

I would turn my 365mag 5000 .Then at 375 hours I put headers,1.8 Rockers,holley 830. and turned it 5400 till 500hours then I rebuilt with blowers.

Re: Proper 454 Mag RPM Range?
 

Ive thought about doing some bolt ons. Just not sure if its worth it. Or better to save money and put towards a already faster boat. My thoughts were to do a intake, cam, heads and exhaust to improve breathability of the motor. Maybe top off with a new ignition. But I already got a Fireball electic ignition system. No points.

Re: Proper 454 Mag RPM Range?
 

If your thinking of a faster boat in the near future dont spend the money!!

Re: Proper 454 Mag RPM Range?
 

Proper range is 4800-5000 rpm... any added weight, beer, food, gas, water..etc along with air humidity will decrease your rpm..... check throttle pull on cable to assure your adjusted correctly... what shape is your prop in??? That will do cut some rpm as well....

Re: Proper 454 Mag RPM Range?
 

Props are in great condition. Considering I boat on a river. :eek: I'll have to check the cable. I am sure they stretch with age and use. Might need adjusted.

And for how soon a new ride is coming along. That will depend on the business venture I am starting. :D