Thanks for the replies I think I will try disabling the choke like ezstriper recommended. Will get a new pertronix flamethrower III distributor because I think the size of the HEI DUI will be an interference to the manifold water outlet and the hatch. Think I will pressure test the exhaust manifolds. I will let everyone know what happens in the spring.

Sounds Like an Ignition Issue , Coil is getting high resistance when warm , Combined with the old points its low spark and hard start.
Pertronix is what I would go with, I put on lots of them at my shop and have no problems , always use a new coil and trash the Ballast resistor.

very cool old boat,i have a 76 hondo true flat that i restored,i take it out 4 or 5 times a year and it is a blast to drive.

the points get moisture inbetween the contacts from heating and cooling. There is a couple of companies that sell a conversion kit to get rid of the points and condenser. Pertronix is one and there is like 2 other companies as well.

also will add the band to the points if it is too weak can cause hard starts -- no starts and even engine running issues as in misfires

I have not worked on points ignition in prob 15 years for boats. Last one was an OMC sterndrive.

Hey Doc, let me come up and take this headache off your hands............;-)

A 79 Sanger flat got me addicted to performance boats. Nothing like sitting in the boat an looking up to a blower scoop.

You don't need mine, you can take your Rayson out anytime.

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