Generator shut down randomly with 7 flashes

[Floatgoat246]

Good day all. Today I’m working on a 44ft searay sedan bridge and would like some assistance if possible. The gen shuts down sometimes an hour after running or doesn’t for hours and sometime will start and shit right back down immediately… always 7 flash and I’ve changed: both fuel filters (primary and secondary, belt, impeller and oil filter just not oil itself. Can anyone assist? Starting to believe it’s a sensor as none have been changed since bought in 08

 

[Little Ducky]

What make and model is your generator?

 

[ttmott]

Onan - MDKB series - seven blinks indicates shutdown due to an overtemp on the exhaust. Loss of raw water cooling.

 

[JB MARSHALL]

I just replace my heat exchanger on the generator yesterday. It was pretty corroded and as it turns out, it was full of pieces from broken impeller fins. I was lucky it still had enough water flow.

 

[Mjresq4]

Check to see if you have good water flow at the generator exhaust. I had similar issue. Like JB Marsh I also found bits of impeller in the heat exchanger and narrowing of the water ways due to build up. I disconnected the hose coming from the exit side of the raw water pump, removed pencil zinc from threaded part of the bolt (not sure if that was needed or not) flushed the bits out, reinstalled just the bolt part of the zinc to plug the hole and poured Barnacle Buster into the hose filling the H/E, let it bake over night, reconnected hose, reinstalled zinc, started gen and noticed a big improvement in water flow. No codes or shut Downs since.