Thread:

overheating issue

Originally Posted by rij1

I have a 1973 Anthony's chaparral with a Oldsmobile 455 high performance.
I just got this boat and wanted to run it on the trailer. So I hooked up the water hose to it and let the water come out the exhaust before I fired it up. I let it run maybe 5 minutes then it started to die. I looked at the temp gauge and it read 240*. I called the previous owner and asked him what temp it ran and he said under 160# in the lake. He said it will get hot running it on the trailer even running the water hose. Is some thing wrong. Shouldn't it run with out getting hot like it did with the water hose?

If you turned the hose on prior to running the engine, then you probably have water in there somewhere. Check the oil for a milkshake...

On the lake/river, the motor starts and spins the pump creating pressure in the cooling system, not the other way around.

Good luck.

Where are you hooking the hose up?

Originally Posted by rij1

I disconnect the inlet hose to the motor by unscrewing from outlet from the Berkeley jet and screw the water hose to it. The hose runs and T's off to the exhaust manifold coolers.

This was/is the correct place to bring water however as 2002CP19 indidicated always start the engine prior to the hose to avoid "milking and hydro lock, Jets rarley overheat period especially with ample water supply such as a garden hose Maybe some photos would help ? especially of the plumbing detail Tom

@ 240 it should have had steam blowing out big time......if it had water in the motor...need to check for flow through the motor......and it might be a good idea to pull the plugs out when you do it...240 is a big number for a car with antifreeze/pressure....Straight water or dry is even worse..water in a cylinder from a blown head gasket/broke head bolt can easily turn a simple head r/r into a motor with a bent rod.

Plenty lucky so far. Keep and eye/ear on it for a while. If it starts getting hot under a load or starts missing, shut it down and figure out why.

Originally Posted by rij1

Will do, thanks

What you're doing is running the pump DRY......Unless you have "unhooked" it from the crank...... You're bumping up against some serious issues here.... Running a jetboat on the trailer is serious stuff and I would suggest you stop until you get some "experienced" help.....

You need to plumb in a "T" in the water supply to feed some water towards the pump. A pipe "T", installed after the main shut off valve, and a common garden hose "bib" will allow you to divert water both ways.....Turn on the water, open the "bib" and "crack" the main shut off open a bit to keep the pump wet. If you have "log" exhaust you should be OK with the water on first as it can't get back over the snails, (risers)..... It's also a really good idea to rinse out the pump from the back before starting. All the "road grit/dirt" is just sitting there waiting to chew up the impeller/wear ring..... If you launch at the end of a dirt road, back the boat in to rinse out the pump before firing on the ramp prior to launching.... (Always a good idea as you don't want to find out the battery is dead AFTER you're drifting away from the ramp.) A few seconds to make sure everything is OK won't hurt the motor, and the pump is already wet inside....
You need to create your own routine, "plug in", "main water valve open", "battery hooked up" etc etc.... Once you get the hang of YOUR routine, it all gets easier......OH, and you'll also need a "loading" routine to get the boat back on the trailer and properly secured....
Ray

Keep an eye on how much water/temp you got going on...to much water flow will crack your heads around the valves. I had an olds an had that happen. I ran mine at 180 degrees to avoid.

post a pic of the motor so we can see how its plumbed and where you hooked up the water to. perhaps you just ran the water to the exhaust system and it wasnt actually going into the block at all... who knows?

sometimes people get creative with their plumbing... we can at least tell you whats going on when we know what we're workin with...