Chrysler 70 overheat concern

[Moxit]

I am new to boating and have a couple of questions.I just put my boat in the water for the first time and it is overheating at idle.Within 2 minutes the buzzer goes off.Just a little water trickles from the exhaust ports and alot of steam.It seems to run fine with no overheating at cruising speeds.I removed the water plug from the side of the egine just below the head and started it up to see if water was coming out of it and it was,not alot but a steady flow.Could this be just a stuck thermostat?Also if anyone knows of anyplace I could buy parts for this motor I would love a link.I'm not sure on the year of the motor,but I assume it came with the boat new and the boat is an 83 galaxie deckboat.

 

[eurolarva]

Re: Chrysler 70 overheat concern

Welcome to Iboats Moxit<br />Because this motor is new to you you should replace the thermostat and the water impeller. You should also get a manual so you know how to do this. There should be a data plate somewhere around the carburator or near the latch for the hood. Post the model number and someone here should be able to tell you the year and what parts you need.

 

[scotiany]

Re: Chrysler 70 overheat concern

Was this engine run in salt or fresh water. If it was saltwater, you could have a bad water pressure relief valve too. But first things first, I would go with the impeller and thermostat like eurolarva says. Try doing the impeller first and if that doesn't cure it, go with the thermostat. Impellers are prone to more wear than thermostats.

 

[Moxit]

Re: Chrysler 70 overheat concern

I removed the thermostat and found that it was stuck closed,so I ran it without the thermostat for a couple of minutes and it didn't overheat.I picked up a new thermostat and Impeller today from a local shop which to my suprise they had in stock and also ordered a new fuel pump diaphragm at the recomendation of a tech there.Everything came to $53.00 which wasn't bad I thought.So I plan to replace the impellar this weekend and I do have a manual to help me out,just haven't looked into how to replace it yet.Is it a big job?I'm a GM auto tech,so I do have experience with engines just not outboards.The model number is #756H2J (I know I made a mistake in the post topic stating that it was a 70hp) =) Thank you guy's for your help!

 

[eurolarva]

Re: Chrysler 70 overheat concern

The motor is 1982. The lower unit it pretty straight forward. The first time you do it is kind of tough, but not too bad. The worst part is adjusting the shift linkage. One side has reverse threads and is kind of confusing. I am not a smart guy and I figured it out.

 

[Moxit]

Re: Chrysler 70 overheat concern

How long did it take you the first time?Im hoping I can get the part on friday and have the boat ready for this weekend =)

 

[eurolarva]

Re: Chrysler 70 overheat concern

a couple of hours. The other thing you want to watch out for is the water tube going up to the power head. There is a grommet that the tube plugs into. Also make sure you reinstall the impeller pin/key.<br /><br />The best way to install the impeller is to put the impeller on the shaft with the pin in. lower the water pump on the shaft. Make sure you lube the inside of the water pump with a little vasoline or lower unit oil. While turning drive shaft clockwise (while looking down at it) put downward pressure on water pump onto impeller. It is going to be a tight fit. You want the curve of the fins to be going the right direction and this procedure will allow that to happen.<br /><br />If you have any problems just post it. Someone will help Good Luck