boat will not run in water

[haus and phefer]

I need some serious help with my boat. I just bought it a few weeks ago. The numbers are model 456ha and the serial is 3378, it is a chrysler. Any help identifying the motor would be appreciated. The boat starts fine, and even runs pretty good on the trailer hooked up to a hose but once you set it in the water it still starts but it wont idle very good and it seems if i choke it alot it will barely keep it going. I can sometimes keep it going in neutral but if i put it in gear it dies within 50 ft. it was miss firing one of the cylinders so i changed the plugs, that got it firing again right. Other than that i have taken the carb off, found a very very small amount of something in the horizontal jet, but for the most part everything looks clean as a whistle. I also wanted to know if the waterhose outlet should be closed up when you are in the lake. Somebody told me that it could make a difference. I am lost, any input will be appreciated thank you.

 

[cotterman]

Re: boat will not run in water

its a 1970, 45 horsepower

 

[roscoe]

Re: boat will not run in water

Time to check the compression and do a thorough decarb, then check compression again. If still having trouble, turn the idle rpm up a little. If still having trouble then, look to the ignition system.<br /><br />Waterhose inlet?? Do you mean the water intake on the lower unit? This must remain open and clear when operating so that water can enter to cool the engine. <br /><br />The difference between the hose and running in the lake, is that in the lake you have backpressure on the exhaust. This is the way it should be, but with an ailing engine, that backpressure is just enough to give you the symptoms you are experiencing.

 

[haus and phefer]

Re: boat will not run in water

I am not sure about the water inlet. I dont think it is in the lower unit. it comes out at the bottom back left around the motor itself. i dont use the muffs to run water thru it. Then again this is my first outboard to work on. So i probably dont know what i am talking about. When i bought the boat i am pretty sure the guy unscrewed an acorn type nut off and then screwed the water hose nozzle on. but he never put the nut back on. so i am not sure if it boggs the motor or not. I am going to start with what you said tomorrow and let you know how it goes.

 

[haus and phefer]

Re: boat will not run in water

Also do you know what pluggs are supposed to be in it and at what gap.

 

[roscoe]

Re: boat will not run in water

It sounds like you have an engine flushing hookup on the engine, which will rinse out any saltwater or sludge from running in cruddy water. I believe this should be capped when running to ensure propper water flow and cooling. But I don't think it should effect the engine performance in the way you describe. <br /><br />I would try to contact the seller and see if he has the cap.

 

[signus-x]

Re: boat will not run in water

I had the same problem last year, would run fine on trailer, but not in the water. It ended up being the exhaust hose was blown and not being spit out where it should. All the exhause floating around in there caused the problem. Might be something to check out.