Fastech 312 Problems
 

New on here heard it was a great site for powerboats. Have a 2000 formula fastech 312 with twin 454 mpi NOT the mag motors. have the factory 28 bravo one props on it and can get more then 3800 RPM 55 mph out of it. Anything i should look at that could be causing the low rpm. and is terrible getting on plan even with the k-planes all the way down. any help would be great thank you. new cap rotor and plugs this season.

Did you just get the boat and are those the props it came with? Have you tried anything else? They seem a little steep for that boat and power.

Often sellers will chuck on any old props they have at the sale. They may not be your best choice.

They're the props from formula good friends with original owner. i ran 26s last year seemed better but still wasnt getting into the rpm range id like to run it.

Did you try calling Formula and getting the info for the correct factory installed props? That would get you a baseline.

Isn"t the 454 MPI 310 HP, rated at 3800-4200 RPM?

4,200 - 4,600 rpm.

think its more like 4600 the mag is even more. atleast this is what im told

with the 26s i can get 4000 maybe 4200. thinking about having them sharpened to get a little more rpm out of it. would that help?

Your right 4200-4600, I had that same engine a few boats ago and remembered wrong numbers. You may have the factory props but they could have been damaged or modified along the way, or replaced with a same numbered set that were worked over.

Do you know anyone with a set of 24s to try?? How was the boat mid range with the 26s?

was actually thinking of trying to borrow 24s from someone to try. the 26s seemed to pull ok mid range these motor just aren't enough for this boat. that i know but they're reliable and don't have to many problems.

You should still be able to pull low 60s. Talk to Brett at BBlades to get props worked. He knows the Fastech boats well and will get your current props dialed in.

Good advise.

I'm no expert, especially with the fastech, but 28's on 310's really seams to be a mismatch to me

without knowing the gear ratio it will be hard to tell you if the boat is over pitched or not. agreed with most. 28's seem a bit steep in general.

Agreed, that was gonna be my next question, I don't think Formula played with the ratio on the 312, but u never know, especially with stock power, my 303 has 1.36 but I'm running 502's

Those props are way to big IMHO. I have a 353 with 502's and it runs a factory 28 pitch prop. I would think you need a 26 or possibly something eve smaller

Check fuel pressure and and change fuel filters.

I had a 312 and every 312 I ever heard of came with 1.65 Bravos........the 454 mag and 502 mag boats came with 30's. (My 312 had 502s and 30's)

Now, maybe those are the right props but somebody put 1.5 bravos on the boat.......making them too big.

^^Very Good Points Made^^