Generator and ethanol effects

I've been tracing a hunting issue with my generator when under load. I have an '04 340 with a carb'd Kohler 5E. I don't know the exact year of the gen itself. When no load, the gen is smooth. Add a heavy load (AC, hot h20 heater and microwave) and it starts to hunt. The PO did NOT run it. There's under 120 hrs on it to date.

I have replaced the inline filter and plugs. Plugs helped some. As of today I did the second routine of pouring carb cleaner directly into the fuel/h2o seperator. Under load with the microwave and AC, it's now running better. It'll hunt maybe 2-3 times as things demand power, then settles under load. Maybe making some progress.

I called a local generator person who said that what I'll ultimately need is a carb rebuild kit. I asked him to elaborate on why and he said that essentally the ethanol gas (the alcohol) causes all the rubber O-rings and such to swell causing restrictions in the fuel delivery to the needles. (there's an o-ring that seats the float-valve in my case to stop fuel flow). Most have said there's fuel-starvation - that seems like the case. As the rubber parts swell, fuel isn't delivered on demand.

What surprised me was the fact that he said I should replace the fuel lines as well. Reason being is the alcohol won't only swell the lines but will cause small pieces of the lines to shed off and cause clogging downstream. I can't dispute it so I wanted to pass it along.

As everyone has said these gensets need to be exercised and loaded up which plan on doing but I wanted to pass along some of the reasoning behind "needing to buy a rebuild kit" which now makes more sense due to the ethanol fuel.

If my second carb treatment doesn't do the trick with the inline filter being in now - I might be ready for the rebuild.

Dale

FWIW

I had to take my carb off and soak it for a couple of weeks as a rebuild kit did not do the trick. After soaking, compressed air and a 2nd carb kit and I have not had any issues since.

I had the same issue. I have an 05 with kohler 5e and would hunt. I tried rebuidling carb but that didn't work. I replaced the carb ($250) and it runs perfect now. Expensive fix but at least it run great now.

What did you soak it in?

What out the wires, cap, rotor and its guts? Have you changed them too? Then spend the $$$ and go for a rebuild. Ethanol didn't start showing up in fuel until 2008/9. I don't know if Kohler started prepping for that before hand. You could call them I guess.

DaleM said:

What did you soak it in?

Click to expand...

http://www.autozone.com/autozone/ac...s-cleaner/_/N-25uv?itemIdentifier=139313_0_0_

on little carbs I remove all rubber, separate bowl, float, needles and slow boil in a stainless steel pot in water for an hour, then blow them out with a air hose

My 5E had a hunting/surging issue. I tried everything under the sun (plugs, in-line water sep filter, kohler fuel filter, fuel pump, fuel solenoid, carb cleaner etc), and finally called in a tech. Ended up having to have the carb replaced because the fuel flow was restricted. He didnt say anything about ethanol, but swollen rubber could be one likely answer as to why the carb was clean but the flow was restricted.

Unfortunately the new carb was installed just as the boat was hauled for hurricane sandy, which also ended up being the end of my season. In the spring, the generator ran fine on the new carb but started this random stalling routine. Turned out the float on the new carb had a plastic burr on it, which caused the float to occasionally get stuck, which in turn caused the stalling as the bowl ran dry. They replaced that carb for free under the new parts warranty. Moral of that story, check the new carb, and also get it from a reputable dealer (or technician if you have it done professionally.)