Trouble after trolling

[Quadruplecccc]

Well, it's only supposed to have a 140* thermostat. That being said, I don't believe it should go much higher than that , should it??

[Still Running]

Temp should be good. When this happens and you get the 1/4 throttle thing, does is break up or run good up to the 1/4 throttle?

[Still Running]

What year is this engine and is it EFI or carb?

[Duffman]

I'm telling ya, water.....

[Still Running]

I'm telling ya, water.....

Sound like it but if he has water at the temp probe and it's @ 150 its not the water. I am think a water leak that is small enough not to make a differance at high rpm.But if that was the case the temp guage would go up. May be a bad temp gauge also.

[Quadruplecccc]

good up to 1/4 throttle. at  that point it falls apart. 76' motor w/carb

[Duffman]

Was slow idling around sailboats snagging bunker for a little over an hour. It was time to get going but the boat fell flat on it's face once I got her up to about 1/4 throttle. Tried many times to get her going but she would respond. I shut her down , pulled the plugs which seemed fine. Tried again, then she quit. Found some water in the fuel ,cleaned it out and tried again. Motor had som time to cool down till I got all this done. Finally got  her fired up and away she went. As long as I don't idle or troll for prolonged time she is fine but when she gets hot at slow speeds it's another story. It'sa 351 windsor I/O .New water pump in lower unit, new manifolds and elbows .What else might cause this condition to occur?    HELP!!   Thanks

  Have to get back to the original post.  You idle along for an hour, take off and it falls flat on its face.  Tough to crank over when hot. Eventually crank and starts when it cools down some.  Right?
  Like I posted earlier, I'm thinking you have water intrusion into the cylinders. Loading up at idle (when you have max pressure from the O/D pump)  and its unable to burn water off when you hit the throttle.
  When were the manifolds and risers done? You say "new". First time on the water with the new parts?  I'd check those gaskets closely, water is getting in those cylinders somehow.

[Still Running]

Does it have points? If so check the coil, maybe be overheating. Also check the timing @ idle, full throttle and when this happens. The capacitor maybe overheating.

[Still Running]

Was slow idling around sailboats snagging bunker for a little over an hour. It was time to get going but the boat fell flat on it's face once I got her up to about 1/4 throttle. Tried many times to get her going but she would respond. I shut her down , pulled the plugs which seemed fine. Tried again, then she quit. Found some water in the fuel ,cleaned it out and tried again. Motor had som time to cool down till I got all this done. Finally got  her fired up and away she went. As long as I don't idle or troll for prolonged time she is fine but when she gets hot at slow speeds it's another story. It'sa 351 windsor I/O .New water pump in lower unit, new manifolds and elbows .What else might cause this condition to occur?    HELP!!   Thanks

  Have to get back to the original post.  You idle along for an hour, take off and it falls flat on its face.  Tough to crank over when hot. Eventually crank and starts when it cools down some.  Right?
  Like I posted earlier, I'm thinking you have water intrusion into the cylinders. Loading up at idle (when you have max pressure from the O/D pump)  and its unable to burn water off when you hit the throttle.
  When were the manifolds and risers done? You say "new". First time on the water with the new parts?  I'd check those gaskets closely, water is getting in those cylinders somehow.

You would think he would see water when he pulled the spark plugs if he had water in the cylinders. If he didn't pull the plugs and cranked it the water would leak by the rings and be in the pan.

[Duffman]

Not necessarily.  Water will pool in the riser or manifold and not get sucked into the cylinder until the engine is under load. 

[Still Running]

Not necessarily.  Water will pool in the riser or manifold and not get sucked into the cylinder until the engine is under load. 

That possable but I would think and don't know for sure. You would think at some point the water would get in the cylinder. Then it would lock up. The thing that bothers me is the 1/4 throttle thing.