75 short shaft hustler build ( beginner please help! )

[Fast Fred]

would need to know what hull you got, and what you plan to do with it, if your goin to roll a bull moose less the gut pile into the bow, peak hp is not what your lookin for...............

[camohunter]

It will go on a 16' aluminum boat that weighs around 300 pounds. They've got one now with a sort of vee pad hull like a bass boat. I've got a 30" tiller handle that I may put on it. I will often have a passenger and gear.

[Fast Fred]

if it was mine i would not jack up the ports, they get peaky, go with a tuner out of a 20", the big lower unit may be better, or put a 3cyl drive shaft in a 2cyl nitro foot, rev limiter box,so i could run most timin for the out of the hole punch, finger ports would still help it,...............the big lower be easier to find props

[Fast Fred]

you can always do what ever you want, i've done all the combinations on many diferant hulls over the years.............

[MGR]

Hey
Fred

I am try to tune my 56er it dies off as I try to come on plane.
What should the ideal and wot Timing be?
Where are the jets on the carbs the one in the front is the low speed right?

O the motor is a 56er with 160 compression fiber reeds and one of Kevin's built tuners
With a nitro case. The boat is a 13 Allison t850 race boat.



Thanks mike

[25XS]

I am trying to tune my 56er it dies off as I try to come on plane.
What should the ideal and wot Timing be?
Where are the jets on the carbs the one in the front is the low speed right? Thanks. -Mike

Mike, if you don't own a factory service manual for your engine, snag one off eBay. The OMC manuals are written very well, include special tools lists and how to use them, and pictures of the proper wire & hose routing to avoid damage from pinch or vibration/chaffing.
Your engine exhibits the symptoms common on this engine where a proper "Sync & Link" procedure should be performed to synchronize the carburetor butterfly opening to the ignition timing advance. Be sure (both?) the roller & sleeve assembly has the clear plastic cover on the throttle & timing cams (not just the black, plastic roller). The "Sync & Link" procedure is described in great detail and too long to post here without the photographs the factory manual includes.
If, after the Sync & Link is done your boat still falls flat on acceleration, start opening up the idle jets to make them fatter. You can 'goose' your choke when this symptom occurs and it it improves then you're likely starving for fuel on acceleration and need to richen the idle (& mid?) circuit.
Hope this helps... Worked on tons of 3-cylinders on fishing boats & pontoons. They need to be set right to accelerate smooth.

[LittleCharger]

Mike, if you don't own a factory service manual for your engine, snag one off ebay. The OMC manuals are written very well, include special tools lists and how to use them, and pictures of the proper wire & hose routing to avoid damage from pinch or vibration/chaffing.
Your engine exhibits the symptoms common on this engine where a proper "Sync & Link" procedure should be performed to synchronize the carb butterfly opening to the ignition timing advance. Be sure (both?) the roller & sleeve ***'y has the clear plastic cover on the throttle & timing cams (not just the black, plastic roller). The "Sync & Link" procedure is described in great detail and too long to post here without the photographs the factory manual includes.
If, after the Sync & Link is done your boat still falls flat on accelleration, start opening up the idle jets to make them fatter. You can 'goose' your choke when this symptom occurs and it it improves then you're likely starving for fuel on accelleration and need to richen the idle (& mid?) circuit.
Hope this helps... Worked on tons of 3-cylinders on fishing boats & pontoons. They need to be set right to accellerate smooth.

Solid advice!!

Mike maybe we can hook up and I can help you get things sorted out. I can meet up with you in Dunnville (ramp or Jeremy's), I'll bring my test wheel, timing light and some props for you to test.

[DeanFHobart]

Make sure the Drive Shaft does not bottom out in the spline...... Binding will occur. There needs to be some clearance..... Maybe .125". Maybe more..... Whatever the stock set-up is.

Good luck in your mod.

[Fast Fred]

20 deg max on a 56er , not goin to find that in a manual, when she falls on her face goin from low speed circuit to high speed circuit is a sign that she needs more fuel to make the jump, to get mo fuel in the low speed, open low speed mix screws or bigger low speed jets, the low speed is in the top front of the carb, with ether a plug, a needle or an air jet.