Onan 5500 Generator
- Thread starter debowill
- Start date
centerline
Well-known member
on the drawing that Dan has posted, see the mounting spring on the lower left of the unit.... the filter will be below this spring going into the electric fuel pump, usually accessed from below the compartment....
some gensets have 2 identical filters, one of them in the location that I mentioned, and one on the carb and some dont.... and some units are fuel injected, so no carb...
because the lower filter is such a small filter and hard to access, I would recommend you get a 5/16" x 1/8"npt barb fitting and install it in place of the filter, and then install an inline filter in a location thats easy to access... you may need 12-18" of 5/16 fuel line to connect to the barb fitting so the fitler can be relocated. the little filter is one of the main reasons for generator issues, because it doesnt take much to cause a restriction....
I recommend a baldwin 836 inline filter, because its a water trap as well.... carry a spare.
some gensets have 2 identical filters, one of them in the location that I mentioned, and one on the carb and some dont.... and some units are fuel injected, so no carb...
because the lower filter is such a small filter and hard to access, I would recommend you get a 5/16" x 1/8"npt barb fitting and install it in place of the filter, and then install an inline filter in a location thats easy to access... you may need 12-18" of 5/16 fuel line to connect to the barb fitting so the fitler can be relocated. the little filter is one of the main reasons for generator issues, because it doesnt take much to cause a restriction....
I recommend a baldwin 836 inline filter, because its a water trap as well.... carry a spare.
recumbent615
Founding MA Chapter Leader-retired
you will find the primary filter under the Generator - accessible from underneath. Also you will find your low pressure pump in the same location. You may find a second filter that is at the end of the fuel line attached to the Carburetor. Newer designs of the Carb have eliminated the second filter - and Cummings says that it is not necessary. If you have one at the Carb - you can still get replacements for that filter. if you do not have one no worries it is most likely the newer carb design.
The Baldwin 836 filter has 3/8" inlet and outlet. Yet, you say to use a 5/16"barb x 1/8"npt fitting to replace the original filter. Something doesn't jive. I will investigate and report back.
centerline
Well-known member
sorry im so late in seeing your question to me..... different builders install different size fuel lines to the generator.. this may be due to how far the tank is from the generator, but im not sure..... ive seen 1/4, 5/16, and 3/8 fuel lines going to the generator, and almost always 5/16 from the fuel pump to the carb....
the baldwin filter with 1/4" nipples is a BF833....
the little screw in filter (OEM) is a baldwin BF837...
you will do well with the inline filter vs the little OEM filters that screw in and clog solid, wont pass fuel and cant be easily cleaned..... there will be one of these at the fuel pump and one at the carb..... if the one at the carb is clean, it can be left in place, but the one at the fuel pump should always be replaced with the larger inline filter.... with the addition of a length of hose between the filter and the pump, so it can be placed where its easier to access....
with the common inline filter, you have more filter surface so it wont clog as fast, and they are easily found when needed, even at small town mercantile stores....
