Sst not turning rpms

[YAMAHAFASTCRAFT]

I got a 56 ci sst 60 wAnt turn harder than 7400 and starts breaking down.it is not to rich by reading the plugs.it just want turn no more rpms.

[hebert51]

What do you mean by "starts breaking down" ? Has it been modified or is it stock ? Id like to see if anyone else any input on this........Im not sure what most guys are getting of the 60 engines, but on our 45 engines wich are very similar and "stock" a good engine usually runs 7500-7800 rpms I have run blocks with identical measurements EVERYWHERE....some just would not flow well enough to spin past 72-7300......

[YAMAHAFASTCRAFT]

the motor actually sounds like it on the rev. limiter.the motor has been ported with fingerports.just getting some advice before we buid another block.

[ima75man]

the motor actually sounds like it on the rev. limiter.the motor has been ported with fingerports.just getting some advice before we buid another block.

my 56 in. omc will turn 8400 rpm's by the tach, might have bad tach, all i have to run against are looper 140's and v-6 merc's. it pulls hard we only run 800 foot. you want to sell it?

[Popa Sam]

If it is an ignition breakdown, first try disconnecting the black/yellow wire from the power pack. That will eliminate the kill switches and wires. If you still have the problem, change the power pack and be sure you use part number 582115. In my opinion the finger ports in a 56 cu in block are a waste of time and money. Getting more in is not the problem, getting it out is, and there is no practicle way of getting more out with a 56.

[850cc racer]

if your saying it is breaking down, have you checked coil packs? i had one that was fine okay until top of the rev range, when testing it once the load would come on the spark would break down.

A faulty stator can also give a weak spark..

[Howie Nichols]

As Sam said check your powerpack. There is a 3 cylinder powerpack that has a rev limiter in it. Check your prop size. With my 12 5/8 x 22 I was turning 8400.

[YAMAHAFASTCRAFT]

It is worse when we have 2:1 gear case on it .but with the I think 1:71 gearcase on it very hardly every does it. I was thinking maybe power pack just wanted some more suggestions.

[Powerabout]

If it is an ignition breakdown, first try disconnecting the black/yellow wire from the power pack. That will eliminate the kill switches and wires. If you still have the problem, change the power pack and be sure you use part number 582115. In my opinion the finger ports in a 56 cu in block are a waste of time and money. Getting more in is not the problem, getting it out is, and there is no practicle way of getting more out with a 56.
Anyone tryed straigening out the passage on the bottom of the block to get it over to the side like a 49?
You would have to re route the water.

[Tim Kurcz]

Anyone tryed straigening out the passage on the bottom of the block to get it over to the side like a 49?
You would have to re route the water.

Actually, surgery to inter-connect the exhaust is easy enough. Re-directing the exhaust through the duct (and tower) is the challenging part. Might consider a casting for the project to make sealing out water easier.

[MHARDEE]

Maby it's loosein breaking psi on the back of the rings is the crank case cut up bad? Reed not sealing on top? Just throwing it out:eek::eek::eek::eek::eek:what did uuuuuuuuSAY:D YEP THAT GOTTA BE THE PROBLEM