Onan microlite 2800 Gas Carburetors
I've recently purchased a 1988 RV with an Onan KV spec J 2.8 gasoline. I was able to get the generator running, but it runs rough, and surges very strongly. All research leads me to believe that the ...
Forum Discussion
Seafoam may or may not "work" but it should not cause harm..
The problem is that just sitting the carb in a vat of any cleaner including Seafoam often will never make it to where the clog is..
The gas could be treated with some Seafoam and allowed to run then shut down for a day or two between runs might help clear a partial obstruction but will not help at all for a full obstruction..
Now, to complicate things abit, there are two types of carbs, gravity fed (tank above) and fuel pump fed (tank below carb).
The link I gave assumes gravity fed, Onans due to the fact that most pull fuel from a tank lower than the carb often will use a fuel pump..
Sometimes the fuel pump is built into the carb operated by the vacuum created by the air moving through the carb body.. Many Briggs engines use that and they call it "pulsa jet".. With that there is a fuel pump diaphragm built into the carb that over time wears out or hardens..
Onan may or may not use that, if they do, unless there is aftermarket manufacturers making that diaphragm you are out of luck..
If Onan is using a external vacuum diaphragm pump (separate pump with a vacuum hose that goes to carb vac port), you may be able to find replacement pumps..
Some may use an electric fuel pump which may be possible to substitute with a low pressure aftermarket auto fuel pump designed for old school carburetors (not fuel injection).
The reason I brought this up is if the fuel pump is weak, your carb may be running out of fuel and hunting causing your symptoms..
But a good cleaning of your carb should not cause problems and is a logical step to trouble shooting instead of simply replacing parts..
The problem is that just sitting the carb in a vat of any cleaner including Seafoam often will never make it to where the clog is..
The gas could be treated with some Seafoam and allowed to run then shut down for a day or two between runs might help clear a partial obstruction but will not help at all for a full obstruction..
Now, to complicate things abit, there are two types of carbs, gravity fed (tank above) and fuel pump fed (tank below carb).
The link I gave assumes gravity fed, Onans due to the fact that most pull fuel from a tank lower than the carb often will use a fuel pump..
Sometimes the fuel pump is built into the carb operated by the vacuum created by the air moving through the carb body.. Many Briggs engines use that and they call it "pulsa jet".. With that there is a fuel pump diaphragm built into the carb that over time wears out or hardens..
Onan may or may not use that, if they do, unless there is aftermarket manufacturers making that diaphragm you are out of luck..
If Onan is using a external vacuum diaphragm pump (separate pump with a vacuum hose that goes to carb vac port), you may be able to find replacement pumps..
Some may use an electric fuel pump which may be possible to substitute with a low pressure aftermarket auto fuel pump designed for old school carburetors (not fuel injection).
The reason I brought this up is if the fuel pump is weak, your carb may be running out of fuel and hunting causing your symptoms..
But a good cleaning of your carb should not cause problems and is a logical step to trouble shooting instead of simply replacing parts..
