Throttle issues and connecting the generator to the calorifier

[mariadz]

Hi

We have issues with a stiff throttle in gear for a few years and decided it had to be dealt with this time. We also connected the coolant element of the generator to the calorifier as another route for hot water.

Hope this is of interest.

https://mariadz.com/2018/03/01/throttle-and-generator-changes/

 

[Monique]

Hello Mariadz,

I have a 7KW Onan as well and Onans eat their impellers.... no kidding! There is only one final solution and this is to install a 220V water pump connected directly to the output side of your generator. The Kubota starts and when power is selected, oopla, the 220V pump starts and keeps the engine cool. I have not done this mod on my boat but I have a powerful IWAKI magnetic pump providing head pressure for the AC system... it is likely to be sufficient for both the Genset and the AC units. (This is the solution on charter catamorons as the genset is higher above water and the life expectancy of impellers is very short)

A work around is the option I took so far. I installed a "blade catcher" in the water pipe to the heat exchanger; the angled portion has a mesh filter and it retains the blades. Works well and I just need to open the angled pipe to retrieve the blades.... when 4 blades have gone missing, I change the impeller. This impeller change procedure is a royal PITA on Onans as you are better off removing the pump altogether than to try changing it in situ. POOR design. But the Kubota engine and its generator are thus far reliable. (A mate just installed a 10 KW Westerbeke and at 80 hours, the thing has gone kaput. He is in Galapagos and cursing the electronic controls on the new generation Mitsubishi engines used by Westerbeke..).