Ok guys can you help me out here. A friend of mine bought a 87 with twin 260 mercruisers and alpha drives. It currently has 23 mirage props on it. One motor spins 3500 the other spins 3300 at WOT. Whch prop should he run on a Baja Force and what pitch?

Also where is peaK hp made or what should he spin it to?

I don't really have any other info but can get if you need more.

Thanks Rob

Hmmm, 33 to 3500 at WOT? Something else is wrong. Start with seeing what drive ratio it is and comparing the RPM to speed with a prop calculator. IF that checks out OK then get some different props. IF it does not check out do a full checkup on engine. Start with ignition and compression test etc. That hull probably has a hook in it from the factory, it will not like a 4 blade.

should be turning around 4,600 to 4,800 need 17 pitch mirage plus props/Darin [email protected]

I have a 87 280 Force also. Mine has twin 454s with 330 hp. The drives are 1:32 alphas with both R/H rotation.

I just changed the starboard drive to a new L/H rotation from Doller. On the old setup I was running Michigan 22p. On the new setup I am running 23p mirages. It runs great.

As you may well know the tachs on these old Bajas are hard to read with all that color. I just bought a new set of Faria guages to replace the old ones.

hey Jimmy!!!!!!!!!! YOU have alot more motor than leathls friend his is 260 hp 350 's any way just wanted to say hello, I grew up there in Ankeny and owned MURPHY'S PROPELLER ON 2ND AVE now D&D /
LATER Darin Murphy

Hey Darin,

Thanks for the note. I no longer reside in Des Moines. Moved to Omaha about a year ago. We loved Des Moines, but Omaha is better with the Missouri river right here.

I did notice that the post was for 350's that's why I made sure to include what engines and drives I am using.

Take Care

I had a 87 350 in my old boat. Definetely ran best once it got up to 4700-4800. I was running a 21 pitch Merc LaserII. Why is he only turning 3500? Boat sounds over-proped but I would think he should still turn more than 3500.

Is it a 1:32 ratio drive ?
look on the l/h decal on the drives,
it should show 1.5R, or 1.32R,
if its 1:32, 23's might be too
big, but I doubt it would knock
them down to that RPM.
Check the tach's against a hand
held tach.

They need to spin in the4600 rpm neighborhood.

jt

I believe the one prop is pretty nicked up maybe that is why the one spins 300 less. They are 1.5 drives. He's gonna check the tachs with a handheld tonight.

Rob

Jimmy

How did the lh rotation change your steering? Any performance gains?