Northern Lights M643. Raw water pump impeller problems.

[grahamdouglass]

I’ve just changed the thermostat on my Northern Lights M643 5 KW genset. Difficult job but got it done.
When I went to replace the impeller on the raw water pump I had an impeller on board, brand new.
The part number of the impeller kit was 25-18325 (Johnson pump 09-810B-1)
The parts number checks out.
Problem. It doesn’t fit. The hub of the impeller is too small. There are three reviews on guys who have bought this impeller and had to bore them out to make them fit into the raw water pump on a M643.
Has any one had a similar story with this impeller (25-18325) on this genset (M643)
Has anyone got a different part number?

 

[Comodave]

Have you contacted Northern Lights and see what they have to say?

 

[grahamdouglass]

I discovered this after their office closed. What could have happened is this.
If the impeller has not been changed in a long time, I bought this genset used, 6 years ago, bought a new impeller, but did not replace. The hub of the old impeller combined with the action of the pin in the middle of the impeller could have widened the split drive pin of the raw water pump. My old impeller was in really rough shape. The fact that two reviews on Amazon mentioned the same thing makes me think this is not an isolated case.
Tomorrow I’ll phone a Johnson pump guy I know and I’ll phone Northern lights. This sounds like a pretty economical hack to get the pump running.

 

[Ken E.]

I have the same generator. Impellers that I've bought for it in the past have had two different part numbers which concerned me, but both fit properly on the hub. I've never heard of a need to bore out an impeller to make it fit on this gen and there are lots of these around. A call to NL should straighten this out for you.

 

[JackConnick]

It could be a 3rd party pump too. Call NL and talk to Scott.

 

[grahamdouglass]

I talked to Scott and told him my theory why it didn’t work and he suggested I somehow reduce the size of the pump pinion. I then re-read my manual, and pencilled in by the impeller part number (25-18325) was another number 25-12009. I phoned up the local dealer asked if he had it and he had one. It fit. My generator runs.

 

[grahamdouglass]

I would also like to add that Northern Lights took my calls and gave me good advice especially on my thermostat instal, which required the removal of the heat exchanger on the non service side of the generator. Northern Lights is a great generator wouldn’t have any other