Honda Water Pump Needs Help

[Believer]

I have a small Honda 4hp water pump that won't pump. The volute and impeller look good. Obviously it won't prime. Does anyone know what the most common failure is? Will I need the mechanical seal or just some of the other seals? Any advice on what to look for to diagnose the problem would be appreciated. Thanks.

 

[Bob Rooks]

Usually when a centrifugal pump won't perform there is excessive clearance between the impeller and the volute. In essence, the vacuum immediately breaks over to the discharge side. Did you try priming it? They are not totally self-priming you know.
Looking good and being within spec are two different animals.:laughing:

 

[Believer]

Yes, I primed it. Is the problem you described something I can fix?

 

[Bob Rooks]

Yes, I primed it. Is the problem you described something I can fix?

You need a manual with the impeller clerance. On some pumps this dimension is obtained by adding or subtracting volute gaskets. Honda makes the engine, who makes the pump? There should be a tag on it somewhere. If it's one of those plastic volute / plastic impeller pumps you may be in for just a new pump

 

[billhall]

I was having problems getting mine to work well the other day and it was as simply as the gasket between the supply hose and the pump had fallen out without me noticing.

 

[20 20]

I would say one of the easiest most common issues is a leaky suction, it might have a bad seal not tight crack........ I know my pumps can be tricky at times making sure everything is hooked up so it doesn't suck air.