1971 18HP water pump

[Blake Hearn]

I have a 1971 rude that i just got running and found out that it is not spitting any water out. I started it in a barrel and ran fine but no water coming out. It has the hole right under the motor but nothing comes out. There is another hole right above the prop and it is putting out something below the water. I assumed this was exhaust. I need step by step instrucitons for taking out the water pump. Any advice is appreciated.

 

[Joe Reeves]

Re: 1971 18HP water pump

In a barrel, the water level should be about 2" or 3" above the junction where the lower unit bolts up to the long exhaust housing so as to have the water pump submerged.

If this is where you had the water level, then the water pump requires replacing.

Replacing pump: Remove side plate from long exhaust housing. Remove one of the 3/8" hex bolts from the brass shift connector you'll see inside that opening. Remove the lower unit retaining bolts. The lower unit drops away.

You might need to use a hand held propane torch to loosen the water pump screws (best not to break them)...... remove and replace the water pump. Reverse the procedure.

 

[Blake Hearn]

Re: 1971 18HP water pump

I filled the water level up some and i got water to flow through. It isnt a solid stream, but ther is water flowing and i never felt the engine get hot enough to be concerned. Should i check it just in case? I have never checked it while ive had it. I have ran it out of the water for just a minute when i first got it. Would this cause any problems from running out of water just for a minute?

 

[Joe Reeves]

Re: 1971 18HP water pump

Running out of water for a minute would cause the water pump impeller to melt.

Water should be shooting constantly out the outlet like it was coming out of a firehose.

 

[1946Zephyr]

Re: 1971 18HP water pump

Joe Reeves is dead on here. You can not run these motors without water, even for a second. You'll nuke out the impeller. It only takes about 5 seconds on a dry impeller to waste it.

You may also check the water flow going up to your thermostat, once you replace the impeller.

 

[F_R]

Re: 1971 18HP water pump

Well not quite like a "fire hose". But a real healthy spray of a mixture of exhaust and water globs. Yeah, I guess firemen do have a hose nozzle that might spray similar to that after all. But on a much larger scale.

 

[lindy46]

Re: 1971 18HP water pump

Well not quite like a "fire hose". But a real healthy spray of a mixture of exhaust and water globs. Yeah, I guess firemen do have a hose nozzle that might spray similar to that after all. But on a much larger scale.

It's definitely not a strong stream like you see from the more modern motors with a pee-hole. A "healthy spray" is a great description. If cooling properly, you should be able to touch the clyinder head for a few seconds without discomfort, or spray a little water on the head. If it sizzles, it's running too hot.