Westerbeke 7.3 surging

mratlndmrk

Well-Known Member
Mar 5, 2018
591
Newburyport, MA
Boat Info
2003 Sea Ray 380
Engines
Merc 8.1s
ZF 6.3 V Drives
Westerbeke 7.0 BCGB Genset
In my new to me 380 my Westerbeke generator is surging. Not terribly but not normal either. It does it with and without load. I have changed the fuel/ water separator (it was completely clean). When I hold down the preheat switch the surging stops. When I release it starts again. The generator has 229 hours on it. Thoughts?
 
It would be helpful to know the model number of the generator. You could add it to your signature.

I'm leaning toward a fuel issue. Holding the Start button on my generator closes the choke which would indicate it's not getting enough fuel. Are you using ethanol or non-ethanol?
 
I am holding down the preheat button not the start button. I assume that acts as a choke?? I don't have the serial number but it's a circa 2003 7.3 EDC series. I am running Valvtect fuel through it but I don't know what it had in prior to my first fill up in May.

It would be helpful to know the model number of the generator. You could add it to your signature.

I'm leaning toward a fuel issue. Holding the Start button on my generator closes the choke which would indicate it's not getting enough fuel. Are you using ethanol or non-ethanol?
 
I am holding down the preheat button not the start button. I assume that acts as a choke?? I don't have the serial number but it's a circa 2003 7.3 EDC series. I am running Valvtect fuel through it but I don't know what it had in prior to my first fill up in May.

My bad...you are correct, holding the preheat acts as a choke on mine. I read in more than one place that Ethanol really messes with the jets. Maybe a carb rebuild is in order as suggested by In Two Deep.
 
Yeah....I'll run some seafoam through it first to see if I can get it to clear out otherwise I';ll pull the carb at the end of the season. It's not bad enough yet to require immediate attention. Thanks again to both of you.

My bad...you are correct, holding the preheat acts as a choke on mine. I read in more than one place that Ethanol really messes with the jets. Maybe a carb rebuild is in order as suggested by In Two Deep.
 
Keep an eye on the output voltage, it might be fluctuating with the rpm change, and some 110 devices don't like that.
 
My experience with gas generators is they tend to surge a bit upon startup. Adding a load as soon as it it possible to do so lessens the surge which usually goes away when the genny is fully warmed up and loaded by running, A/C, water heater, ice makers, fridges, etc. these machines need to work to run well. My WB seems to need spark plugs about every 50-60 hours, and my service tech adjusts things when it starts to hunt. This is never a big expense, but these genny do need attention by techs who understand their workings. Fall layup is a good time to make sure all is in good order before putting them into storage. Make the new season more enjoyable.
 
Same problem with my 7.0 BCGD. Ran Seafoam thru twice this spring, and have always dosed it properly with Startron since installed new in the fall of 2013. WB certified service guy is going to try replaceing the carb. Like yours, the surging/hunting smooths out when I hold down the preheat button, but this causes it to run very rich, creating quite a smokescreen.

Surging causes voltage spikes, which can cause a blowout of the capacitors so do NOT run it when it's doing this. Interested to see how your issue turns out.
 
Just to tidy up this thread, I had the carb cleaned and there were a couple of blockages but it is running smooth as silk now. Thanks to all for your input.
 
Replaced my carb and mine's working now. Going to get the old carb rebuilt. Guessing this is going to be an annual or biannual thing.
 

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