Thread: Runs great for ten minutes then dies

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It does sound related, but I really don't think it is...I've been a gear head and Chevy 350 guy for a long time and it just doesn't seem like its overheating, maybe I'm wrong though

The only other difference between the land and water runs were the land run was idling for 30 minutes, the water run it was at 4k for ten minutes

I'll do the ignition stuff this weekend, if it doesn't work I'll look into valve stuff and overheating stuff

Solid lifter lash is set with a feeler gauge. You need to know the cam to set the specs. I am sure there is a rough standard but I cant remember what it is. It has been 30+ years since I built a motor with a solid lifter cam. Maybe Jerry, Pat or ? can chime in on that.

If it runs fine though with the hose hooked up then it seems likely that the issue is maybe too much water going into the motor when out boating. Or maybe not enough like Charlie mentioned. Check the water intake area on the hull to see if it is plugged.

Last though is to contact a boat place and run it by them. They might know right off the top of their head.

Delete, I re-read your first post and got my answer.

Points for a dual point Mallory----do you know how to install them????? is it a 4 lobe distributor?????

No idea, how hard can it be though? It's an 8 lobe with tach drive

I would keep looking into other things before you start changing out the points and other items. If it runs fine in your drive way and at the lake up to 4K for 10 min then points, plugs, rotor cap, distributor cap & wires should not be the problem. You could just manifest the issue throwing parts at it.

It seems to me (like was mentioned before in the posts) something is either getting heat soaked (condenser, coil, ect) or it could have something to do with the water flow while out boating.

As I mentioned in a previous post, check with a place that works on boats. I think that it is BOAT related. You might have something hooked up incorrectly (hope that is all it is).

Yeah that makes total sense, I think I'll just replace the coil then check it. If that doesn't fix it I'll check the other suggestions I've gotten here. Cuz I know the points cap and rotor aren't the problem. They are about 10 years old though so were due for replacement anyway

Just a thought, does it have a ignition coil ballast resistor? A weak resistor (12 volt side) will lose value when it gets hot (go high) and shut the coil off until it cools. Also a resistor coil wire (high voltage side) will do this.

The condenser (capacitor) stores voltage, momentarily pushing the current ahead of the voltage, this reduces metal transfer and the points last longer (without the condenser the points burn rapidly). A bad rotor or cap usually causes miss fires caused by contacts arching due to wear, or back fires due to carbon tracks conducting to the wrong cylinders.

My thinking is a bad coil as I had two Accell super coils do the same thing in my 66 Mustang which is also running a Mallory dual point distributor. I changed the distributor to Petronix as I grew tired of setting the points.

If it was a old ford from the 70's, I would ask if the same brain was in the boat like in the old LTD's that used to over heat and not start till they cooled down.
I don't know if anywater can get around your engine, But after it dies on the lake I would say to pull the distributor cap and look for water or condensation in the cap.
That will cause it not to start till that dries up.
Kurt

sure sounds like a heat problem to me - - - - - seems like the temp is the "only" thing that would change the performance after 10 minutes of operation - - - -don't some marine engine set-ups have an automatic shut down when the temps get excessive???

be sure and let us know what you find out about this, OK?

meller

Water in the cap is the first thing I checked, bone dry.

It isn't a marine engine so wouldn't shut down from heat

I got all the new ignition parts, just gotta find the time to install em
I will definitely let you all know what fixed it, thanks for all the help

Water in the cap....What cap. Do you have a radiator on there?????

Distributor cap

I would bet good money your coil is bad. Had a boat do the exact thing. Ran great, got hot, would not run...I tried everything...A buddy said he thought it could be the coil and happened to have one...Been fishing every since...