1979 Water pump replacement gone bad - 4 horse

[skybolt_1]

Hey everyone,

I'm really frustrated... I have been trying to get my 1979 4932D 4 horse up and running, and have had nothing but problems. I replaced my water pump (completely, including housing) after the motor started overheating and shutting down. Now, the pump doesn't seem to be working whatsoever. I have taken it apart 3 times, double-checked the directions, made sure that the vanes on the impeller are twisted the right way and made sure the tube is seating properly.

I also took an air compressor and blew out the water jacket - it seems to be clean, blows out easily enough.

Another thing that I've noticed is an electrical-like snapping when the motor is running, coming from the igniton modules. Is this normal?

Any suggestions would be appreciated...

skybolt_1

 

[Paul Moir]

Re: 1979 Water pump replacement gone bad - 4 horse

Is there water misting out with the exhaust? How long does it take to start overheating?

Snapping noises are not normal. Try running it at night and see if you can see arcing.

If you want to test the water pump once and for all, try setting the lower unit in a body of water and spinning the driveshaft with a hand drill. Naturally, a cordless one would be preferred due to the water but you can protect yourself with a GFCI outlet.

The pump must be submerged to prime.

 

[Silvertip]

Re: 1979 Water pump replacement gone bad - 4 horse

No snapping should occur. Start the engine at night and see where the spark is coming from. If you see arcing, the engine cannot possibly be running correctly either. Check for cracked coils, bad wires, loose terminals.bad boots, etc. Excessive dirt and oil on the coils may cause the spark to take a short cut to ground.

 

[skybolt_1]

Re: 1979 Water pump replacement gone bad - 4 horse

OK I will try it with a cordless drill and run the motor at night.

If the pump doesn't work, then what? take it to a pro?

 

[Paul Moir]

Re: 1979 Water pump replacement gone bad - 4 horse

Nah, you're in too deep now.

If it doesn't pump with the drill, then 1 of two things is wrong. 1 is the intake is clogged or partially clogged. 2 is the wear plate or pump housing is badly worn. Both those should be obvious by looking at them.

What I was trying to feel out is whether you've got a partially clogged cooling system in the block. There are two parallel passages and if one is blocked then you'll still get the mist but the engine will overheat after running a few minutes at full throttle. At idle and part throttle it will normally not overheat if you've got that condition.

 

[Scaaty]

Re: 1979 Water pump replacement gone bad - 4 horse

One thing at a time. Pull the lower, and with a drill stick it in a bucket just up to the outlet and spin it. If ya get a face fulla water, toss it on the side bench and pull the head on the motor and have a look see in there. But first, are you SURE the key is in the impeller, AND the water pipe is seating? Amen on the nighttime check for what you MIGHT think is a electrical snap...and don't take it to a pro...we know more than most anyway, and don't charge $80 an hour. And as I have a 84 4hp, there is no telltale (not sure on the 79), but runing in a garbage can, if you put your hand behind the little exhaust holes, you will soon get a wet hand. It won't be anything major, as 90% goes straight down and out with the exhaust. If you are doing this with some sort of muff, there will be no body of water to pressure some out those little holes, but still cooling well, ya just can't see it. And mine also makes a snapping death rattle at a certain rpm. but its just intake noise.

 

[skybolt_1]

Re: 1979 Water pump replacement gone bad - 4 horse

Thanks for all the tips. Sorry about the delay in reply.

The water pump started working. I have no idea why. I think that maybe my bucket wasn't deep/wide enough to provide a steady intake for the engine, but now it works fine when I'm buzzing around the harbor. Plenty of water out the spit-holes and no overheating. (I think that my dental-pick cleanout of water channels helped a bit)

The snapping is definately electrical. As my time has been limited, I've only been able to run it once at night and I wasn't able to take the cover off beforehand, but I could clearly see blue arcing going on. Just not sure from what.

Should my next step be to degrease the coils or replace them outright? The area is awfully oily - years of grime.

 

[dsinger]

Re: 1979 Water pump replacement gone bad - 4 horse

I would start with plug wires and boots.