rpm
 

not sure if any thing is rong but i cant get my rpms over 4200 wide open and trimed out i was told it should turn more like somewere in the 4800-5200 its a stock 7.4 (454) mpi with stanless marine exhaust is that true

What prop are you running?

I think your motor has a 4200-4600 operating range.

So you wouldnt be to far off.

You can drop a couple inches of pitch to get it higher.

Generally speaking for a pleasure boat, on a cool day no gear, no fuel, 1 or 2 people you should be right at the high side of the rpm range.

If all your covers are intact on the motor, the operation range will be right there on a sticker

:eek:23p , Can i reprogram the computer to get higher rpm or will that mess the motor up if you can even do that. i feel like the boat should be faster, and it has truble planeing out but the motor sound great. oi was thinking the boat sould run around high 60s maybe 70 stock :eek:

Is your boat a Baja 240?

For referance my 1997 turns a 23P Mirage Plus at 4700-5000 with the 7.4L carb and runs 63.5 on GPS tops. The differance depends on water conditions and where I can trim to.

One would think the MPI would out perfom this. Have you verified the speed with GPS? You could also verify your Tach reading as well.

I should add my numbers were lower when I first took the boat out after buying it this spring, I contribute that to the storage time of the gas (18mo). The first time I filled it with fresh 93 after runnig it empty the numbers came up considerably.

I have a 24P Ballistic XL i am going to try this weekend and will post you the results.

23P Mirage is what i am running to but my boat is a 88 226 sport, the one in my profile pic, i hear there the same as the 240 outlaw kind of any way, i have had people tell me it should run around 70 easy with the 7.4 mpi. I need to gps it but it doesnt feel like it runs that fast im going to try a 21p 4 blade this weekend to see if it gets on plane faster (let me know how that 24P Ballistic works out for you.)

Mine is the Baja 240 same boat only the complete fiberglass dash and not an Outlaw. I will post the numbers.

http://images5.theimagehosting.com/240 Side.th.jpg
http://images5.theimagehosting.com/240 Frontside.th.jpg

well i tryed the 21p 4bl/ came out the hole a little better until i had 5 people in the boat then i had to get 2 of them in the front so it would plane out and i did find out that my rev limiter kicks in at about 45-4800 but i can only hit that if i rev it out of gear maybe my boat is ment to be slow:lolhit: i hope not.

21 4 bl isnt must different then a 23 3 bl load wise.

Try a 21 3 bl mirage plus and I think you will be there

ill have to fine one

Agree...

My 29ol with 7.4 MPI's rev limiters kicked-in about 4650, but the older 7.4 carbed motors like my 92' 240 would run almost 5000 if overtrimmed with a 23p Mirage. Rev limiters were the best thing invented for marine engines...

XT

100% right!! if you had MAGs (385hp) not MPIs (310hp) you would be able to push them a little more. Not the MPIs ive been thought this already.

good luck.

did you change your fuel/water filter that can cause a loss of 200 rpm. give brett at bblades a call he has a prop exchange program, but if you didn't change the f/w sep do that 1st.your hull is different from the ol hull your is a 21 degree if I remember 240 sport /ol was 24 degree.

thanks guys, i looked on my motor covers and it dose say rpm 4200-4600 so i should be able to pull 4600 right, but im not so i guess ill try a smaller pich prop

Call brett he has a prop exchange he may let you try a small prop but it might be higher rpms but slower speed. you will pick up speed with a labbing a prop and rpms. also check the fliter I told you if you did not put a new one in. a labbing can get you up to 300 rpm. but brett may want you to try a rev 4 prop 25p they have worked good in bajas cause of the deep X= deep prop shaft. I will ask him to look over here if he has a chance he could explain better than me. your boat should be faster than a ol 24 cause its lighter/smaller deadrise 21 degree not a 24 just don't go buying props from Co's that once you buy it your stuck with it.:coolcowboy: call me if you want 617 833 3327, just hanging around two day waiting for flywheel and driveplates so we can put the 1100sc in the boat.

thats cool ill try to call you later thanks