350 Chevrolet

Hi all,
OK I have a 350 Chevrolet inboard.
It runs great however once it is turned off and left for awhile it will not start again. .
If left overnight it will fire up first turn of the key.

Not sure where to start looking for a solution?

Thanks,
Mike

 

Could your induction coil be getting to hot, heat reduces efficiency of induction coils.
I discovered that to be the problem in one boat, and I water cooled the coil, problem solved.
When a motor is switched of the heat flows through out the engine compartment because air flow stops.

 

Hi Tom,
I've got a Hei distributor
Could the coil to getting to hot on this system ?

Thanks
Mike

 

Don`t make too many changes when trying to track a problem, one at a time is best, then check it out to see if that is a cure.
I can only suggest that over heating ignition coils could be the cause and finding a way to keep it cool would require further research for a solution for your set up.
Google some question may bring an answer. Maybe air cooling'
If a motor runs very hot and is shut down with out time to cool a little the motor can become very hot and that heat can "kill" the induction tube vacuum and make a motor hard to restart, until the motor cools down.
My solution was to cool the induction coil (single) with a coil of copper or plastic tube (small diameter) wrapped around the coil and fed cold water from the motor cooling system.
This is unlikely to suit your motor.

 

when you say HEI, do you mean you have a Delco car distributor with coil in the cap?

 

Correct powerabout

 

I had engine running this morning and tried to start it this arvo took heaps of turning over when it finally fired up a heap of oil or black soot was floating in the water behind the boat ??

 

HEI isn't subject to heat soak like a conventional style of canister coil. A simple solution for the can coil is to just move it from the top of the engine to someplace else.

It could be a few different things, but I'd look at the carburetor first. Black smoke is way too much fuel usually. Is the choke working right? This is often combined with oil from leaking valve seals and rings. We call this overfueled and it's pretty common on non-computer controlled engines.

You may also want to pull a compression check too. Once it's running put a vacuum gauge on it, to check for timing, sealing and valve train issues. Odds are your valve guide seals are leaking down, maybe you have a poor valve seal at the seats, low compression, etc. It's probably be a combination.

 

An overflowing carburetor can do that. There is pressure on the fuel line after the engine stops, so fuel will run into the intake manifold and flood the engine. If you wait long enough, the excess fuel will evaporate.

 

The most likely problem is percolation caused by heat build up when the engine is shut down when hot. You can usually see this by removing the air cleaner and then shutting down. You will probably see fuel dripping into the intake from the carburetor venturies. Usually this is caused by too high float levels you may have to set them lower than recommended. Anyway it sounds like the problem is that the engine is flooding with fuel after it is shut down hot so make sure the choke is opening all the way and look in the carb after shutting down hot and see if you have fuel dripping into the intake.