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Chris Craft 283 - can't get over 2500 RPM

1

1956Holiday

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Hello,

I have a 20' 1956 Chris Craft Holiday with a 283 engine and cannot get faster than 2500RPM when in the water. I had the carb rebuilt and even put in some GUNK fuel system cleaner. Sounds great, no vibrations, etc.

Appreciate any suggestions or direction.
 
Had a friend that came over.....

Did a couple of things.

1st: Had the manifold cover on backwards on one side and the rockers were rubbing against the covers... Oil was actually coming out and the metal "pulsed" due to them pressing on the cover. Thought is that they might have gotten stuck. I am a novice........:rolleyes: and did not know they could go on backwards.

2nd: Adjusted the choke. I had lots of trouble starting the engine when it was hot and adjusted the choke far to the opposite side. I can start when the engine is warm, but it looked like the 3rd and 4th barrels were not opening up due to that adjustment. Gonna take her out and see what happens.

1956Holiday said:
Hello,

I have a 20' 1956 Chris Craft Holiday with a 283 engine and cannot get faster than 2500RPM when in the water. I had the carb rebuilt and even put in some GUNK fuel system cleaner. Sounds great, no vibrations, etc.

Appreciate any suggestions or direction.
Click to expand...
 
I've had nothing but trouble with my 1981 305... all caused by Ethanol fuel which has "phase separated". Try pumping some fuel out into a glass jar and see what it looks like. If its cloudy, than you've the the same problem I had. The only thing to do (I believe) is pump out the tank and buy only non-ethanol gas.

You could check to see if it is a gas issue, by re-routing the fuel pump intake into a "jerry" can with fresh gas in it. Just be careful of those gas vapors... they can go to the bottom of the boat and cause an explosion.

You also should check your distributor timing, etc.

Or the propellor could have too large a pitch... loading down the engine. Did it ever go above 2,500 rpm?

Bob S.
 
What do you mean by "3rd and 4th barrels"? Does this engine have Twin 4 BBL Carbies?

Never heard of being able to put a Manifold on backwards, but then, I am willing to learn.

I would be checking the Timing, and the Timing Chain, in case someone has installed a car Timing Chain with the nylon teeth, and these have fallen off.

I would also be recommending a Compression Check as well to check the condition of the Rings, and Valve Seats. Do the dry check first, and then the wet check. then compare the results.

Bruce.

PS. The Wet Check is to squirt some oil into the cylinders and rotate the engine and use the Compression Gauge again. Doing this will give you an idea of the sealing capacity of the compression rings, as the oil becomes a "temporary sealant".
 
I fully agree with checking to see what your progressive spark advance is doing.
No progressive advance, or insufficient progressive advance, and you will not get any performance from this or any gasoline marine engine.

You'll want to mark off your harmonic balancer up to approx 35* or so, and then strobe this throughout the RPM range up to the Full In RPM.
See your OEM Marine ignition specs.... DO NOT guess at this, and do not use automotive specs!!!!!!!



As for squirting oil into the cylinders for a pressure test; Note that with any V engine, the oil will tend to pool at the low side of the piston ring landings.
This is an old school test that came about during the age of in-line and vertical cylinder engines, with flat top pistons.
It works well on this type of engine, but does not work well on a V engine, or any engine with dished pistons.


If you are going to do this for a V engine, do not expect accurate results.
Use an equal amount of oil in each cylinder, as the oil itself will increase cylinder pressures simply due to the volume that it consumes.
This is not a good or accurate test for V engines, IMO.... unless you are somehow able to get the oil to remain at the perimeter of the ring landings only.

I could squirt oil into dang near any V-8 engine, and show you a false and temporary increase in cylinder pressures.

You may be better off doing a cylinder leak-down test.

.
 
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It could also be a distributor with rusted or cruddy advance springs.
If you rev the engine and you don't see movement at the timing light, THAT would be the problem.

People often change out points, rotor, and condenser, but fail to ever take that top plate off and look down inside to see the springs.
You can still get springs for the old distributors if you need em.

DS
 
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