astar77350

I just bought a 88 baja 240 sport, with a 454 mag. I am running a 4 blade prop, not sure the pitch but im sure its around the correct pitch for the boat (22-25) The boat runs 4100 rpm @ WOT. can't quite get to 60 mph. Does this sound normal for this boat?

Blueabyss

There is now way that boat will do 74 mph with a 454 mag. I think 64 would even be a stretch.. On GPS that is.. I do agree you need to be turning more RPM. With a smaller pitch prop you will come out of the hole better and prob pick 4-5 mphh on top.. Those boats like 3 blades for speed and 4 blades for Skiing or tubing.

Chris

stlliberator

iTrader: (1)

74 is a strrreeetttccchhhh..I have a 502 in mine, and turn a 26 bravo..but I have my x demetion raised 3 inches...

jeffswav

He does that all the time. He is just trying to stir things up.
You should prop the boat for about 5000 RPM. A Mag engine has forged internals, you can run a mag engine higher in the RPM range if it does not have a limiter. The cam is not designed to build power after about 5000 RPM, you will most likly not go any faster. A 3 blade 23p mirage prop should work the best for speed. You should see about 61 or 62 on a GPS. If you do not see these sort of numbers try checking the timing, replace wires, plugs, cap ect...

AIR TIME

when my baja 24 was new in 88 it had a 454 330hp and did 62 on speedo, a friends had a 454 mag365hp did 64 speedo, I also moved up to a merc 502 in 93 390hp was getting 67 on speedo. props were mirage 23 non plus, for the 454s and 25 for the 502. the drives are deep on these boats so up grading to a imco 2'' shortie gives better handling and speed but you need a 1990 b1 drive or newer the 88 drives had a smaller case and different inside.

bajabob

jeff is rigth and airtime!!!i have the same boat 365mag 150 bravo drive 21mirageprop did 62 on the stock speedo back then i didn t have a gps so i dont no the real speed .

bajabob

the baja likes mirage props 3 blade. if you want to run a 4blade you have to go down a pitch. so i would put a 20 or 21pitch . like they said 5000is what you want to prop your boat

astar77350

i guess my main concern is why i can't get more out of the engine in the rpm range. If i switch to a 3 blade, will that increase the RPMs up almost 1000?

Rookie

iTrader: (4)

You need to give the right information to get the right answer. What is the pitch of your prop? Make sure your tach is correct. If you don't know how can these guys give you the right answers. 3" of pitch could be a swing of almost 600RPM. One of my best friends has had 2 of these boats. The first had a 330 that did 58gps with a 21 Mirage+ and the other had a ZZ502 with a 22" Bravo1 that did 72. He now has a 557 and runs around 80 with ~630HP. It takes a lot of power to get these boats moving.

AIR TIME

thats cause of the x ,prop shafts are to deep a 2'' shortie will help on speed and handling will be better. also find out what size prop you have and if you have the mag which was 330hp in late 87, then came the 365hp mag in 88 and stock 330hp 454. that makes a different on which hp you have.