old chrysler 75 hp not staying running

[skyzoo]

I got this boat,and it has not been ran for a least ten years. it had no spark, so i went and bought a used cdi box. I got a spark and the motor runs and runs good the only problem is that it only stays running for about 5-10 min. then it just shuts off. when it shuts off I can not get any spark at all. I took the plug out and tried to start it and no spark. After about 15-30 min. it will start again, and do the same thing. The starter also get very hot, could that have something to do with it? if anyone has any info. please HELP!!!!!!!!!! I know nothing about boat motors( first boat) I think the year is 1977

 

[turtle1173]

Re: old chrysler 75 hp not staying running

Skyzoo,<br /><br /> I'm sorry I'm the only one replying to your posts thus far. Hopefully you will get some others (more knowing than me) to answer you soon.<br /><br /> It sounds like to me that when the motor gets warmed up, it is shutting down. This suggests that something is getting heated up to a point where it stops working and therefore stops the engine. What condition is all the wiring in?<br /><br /> Do you have a model number for this engine? Does it have a distributor and 1 coil?<br /><br />Shane

 

[skyzoo]

Re: old chrysler 75 hp not staying running

the model # is 757HB<br />Ser. # is 14315?<br /><br />Thanks for all the help

 

[NathanY]

Re: old chrysler 75 hp not staying running

This may be a silly question, but do you know for a fact that it is pumping water?<br /><br />Also it sounds as though you might have a condensor failure, or your switchbox is not good. You might want to check all your wiring for corosion, bad connections and possible shorts.

 

[skyzoo]

Re: old chrysler 75 hp not staying running

I know that it is pumping water, but I don't know if it is pumping enough. it just a little water coming out.

 

[NathanY]

Re: old chrysler 75 hp not staying running

If you dont know how long it has been since the impellor has been changed, that means its time to change it. Your motor might be getting too hot and causing electronic failure, and your motor dying.

 

[Terry H]

Re: old chrysler 75 hp not staying running

Skyzoo...your motor should be a mid 70's maybe 1975 model with magnapower ignition. When it shuts down is the motor overheated? You might try the hair dryer trick...when you have spark try heating the ignition components to operating temp one at a time ane see if you can figure out what part is failing. I would be careful with heating the distributor, but the coil or magnapower box could be especially suspect. Make sure wiring is not shorting to anything is shouldn't be...just a Thought

 

[turtle1173]

Re: old chrysler 75 hp not staying running

SkyZoo,<br /><br /> It looks like your motor is probably a '75. It should be distributor driven. I would check all the connections carefully. Make sure none of the wires are frayed or corroded. Also make sure all wire connections are tight. Pay close attention to where any wires come in contact with the powerhead.<br /><br /> Your starter getting hot wouldn't have anything to do with the motor shutting down. Something is heating up and causing the motor to cut out. Then you have to wait til it cools down to be able to restart it again.<br /><br /> Are you running the motor in the water or on muffs?<br /><br />Shane

 

[skyzoo]

Re: old chrysler 75 hp not staying running

I was running the motor in the water. I'll go and get a new impellor and see if thats the problem.<br />Thanks <br />Joey