Heats up then Locks up...why?

[DuckMan87]

I have a 1981 johnson 4hp (J4WCIC) I use it mainly for duck hunting after oen day of breaking ice with it it heated up to the point it just locked up!! I figured it did it due to the fact of i was breaking ice with it. once it colled down it fired right back up. The next year took it out after it running like crap for 100 yards or so it did it again...drug the boat to our area and parked it, on the way out it ran great the entire way!!

The reason im asking about it is that i dont need it happening again this year, i assume the water pump is shot?? Any info yall might have would be greatly appreciated TY!!

 

[crxess]

Re: Heats up then Locks up...why?

You can produce more power with your legs. Why abuse the motor?

I would get a head gasket, pull the head and see it the cylinders are scored. Check for ring damage and inspect water jackets for blockage.

Drop the lower ans replace the water pump impeller.

Fire it up in a bucket and make sure it has good water flow.

Don't know if the 4hp has a thermostat, but is so replace it also.

 

[Daviet]

Re: Heats up then Locks up...why?

I don't see a thermostat in the parts break down. I would do as suggested and replace water pump and remove cylinder head and check for damage.

 

[DuckMan87]

Re: Heats up then Locks up...why?

will do ty