Kohler Generator - Liberty installation - Part II

[phorner]

OK...so my temperature appears to be fine.

But my paranoia was apparently justified. A new problem has developed.

As soon as any substantial load is placed on the generator, say 10 amps or more, the generator RPM's start to drop, there's some stumbling of the engine and it acts as if it's about to shut down. If a load is applied, it acts as if it's fuel starved.

The generator has operated fine under substantial loading for the past 4 days while dry camping but now won't handle much more than 5 to 10 amps of load.

My first thought is to change the fuel filter, but I know it has less than 100 hours on it.

So.... anybody have a similar experience???

And here I was under the delusion that all was well......

[JIM CHALOUPKA]

Paul, check to see if your fuel hose has deteriorated to the point of allowing it to collapse, thus not permitting full flow.

There is available heavy wall fuel hose, for fuel injection use at better auto parts stores.

JIM :o

[BoaterAl]

Paul........ 12.5 Owan gen, changed fuel filter as part of run-time maintenance. Within 10 hours the gen shuts down. The only thing I can think of with this problem is the load coming on line was exactly what tipped me off to replace the filter. Problem solved
Having been in the parts business it is not uncommon for fuel filters to fail. Could be a mfg. issue where the paper waffers don't mesh for example. This is not common in oil filters as the better oil filters have by- pass valves so the engine is protected.

I would replace the fuel filter ASAP.

AL

[dreamchasers]

Paul,

When you need your generator and it does not function properly, it can be a bummer. My coach has a 17.5 Powertech generator. While in Washington DC last year, it shutdown at 3:AM one morning while it was very hot outside. The next morning while troubleshooting, I tapped the small electric fuel pump mounted on the side of the engine and the fuel pump started clicking (pumping). So I started the generator and as long as I tapped the electric fuel pump, the generator would continue to run. My symptoms mimicked that the generator was dying when load was applied. I was thinking all sorts of scenarios that all looked "ugly". I replace the electric fuel pump and all was well. My electric fuel pump is a round cylinder shaped unit. If you grab it while the generator is running, you should feel it clicking.

I ordered a replacement from Powertech. Unfortunately, the replacement from Powertech was not a direct replacement. I had to re tube the fuel inlet and outlet. I have since found that the fuel pump is easily ordered on line from other suppliers and I could have had a direct replacement. Powertech no longer uses the type of electric fuel pump, thus they send out a different type.

Now, I always carry a spare electric fuel pump for the generator.

Also, I had an experience that paralleled Boater Al's with an Onan. I had fueled up during Hurricane Katrina in Jackson, Mississippi and the fuel was water contaminated. The main engine had no problem with the fuel, but would plug up the fuel filter on the Onan. After replacing the filter three times, I was able to run enough of the bad fuel through the Onan to start using good fuel again (I had refilled the main fuel tank). No problem after that. My Powertech has a water sensor on the Racor filter that will shut the generator down if water is detected.



Hector

[LNDYCHT]

Paul
All three above posts are right on the money. The most probable cause of your issue is fuel starvation of the primary fuel system (pre injection pump). The other possibility would be low fuel level, if you are below a quarter tank.

[Jon Wehrenberg]

Paul,

FWIW at about 1000 hours our Kohler would die under load. Replaced the fuel pump (pricey) and all is well. I heard, but cannot remember where or have any way to verify this, that our Kohler gensets had problems with the fuel pumps.

Mango had problems with his at the Albuquerque balloon fest and the three Taco Twins (Mango, JDUB, and Truk) went and got a cheap electric pump from a NAPA type store for about $1.69 (must have been for an old Edsel) and jury rigged it to keep the genset working. My point is if you are not sure it is the fuel pump you can probably get a cheap one to bypass the factory pump to verify the problem before spending $200 to $300 for a replacement.

As an alternative you might consider removing the downstream fuel line and running the fuel pump, measuring the flow. With no restrictions it should flow vigorously. If you restrict the flow it should build up some pressure. Use jumper wires to run the pump.

[truk4u]

Paul,

Order a pump and we'll replace it at BT. In Albuquerque as Jon pointed out we matched the pressure pretty close and had Mango going in no time. Jdub got a tad wet and we used Jon's credit card number, he never caught it.

[phorner]

Thanks for all the info regarding the fuel pump. Mine had the fuel pump replaced in 2007 as part of our PDI as it was leaking. However, everything mechanical has a life...

The good news is that I may have it resolved. On the way from Perry, Georgia to the Oysterfest we stopped for a lunch break at a rest area along I-65. The place was empty and spacious. Looked like the perfect spot to throw on a couple of new fuel filters. My generator takes two and it just so happened that I had a spare pair, a small container of diesel fuel to prime the filters and an oil drain pan to place under the generator so as not to make a mess.

So, in a matter of minutes the offending filters were swapped out for new ones and the generator fired right up. I have not yet tested it under substantial load (I'll give it a try tomorrow) but the early results look real promising.

Thanks again for all the responses coming to my rescue.....

[Jon Wehrenberg]

Paul,

One thing to remember on our generators. They run best when loaded. A generator that runs under low loading tends to get carbon build up and steady running under a load keeps them running better.

We were next to a Canadian island owner in an RV park who had a seasonal fishing lodge. He used two generators like ours. He encouraged guests to leave lights on and otherwise use electric. But out of habit the guests did not, so every month he hooked the generators to 7000 watt heaters and were run that way for several hours to "clean" them up.

He had over 30,000 hours on the generators when we spoke.

[phorner]

Jon,

Excellent advice regarding the necessity of running our generators under load and not simply starting them up on occasion.

I fired up the generator this morning and ran it under substantial load (30+ amps, each leg) and it ran flawlessly for 30 minutes. I saw no need to subject my neighbors to more generator exhaust than that.

Bottom line is that a change of fuel filters solved my problem. The issue was definitely fuel starvation. A good clue was that the problem got progressively worse, and rapidly so, until the generator refused to run at all.

My fuel filters had only 91 hours on them.....but had not been changed in 15 months!

Since there were so few hours since my last generator service, my plan was to do a complete service when I got back from this trip and be prepared for summer travel.

Lesson learned here is to pay as much attention to time as to the hours (or miles, as the case may be) when doing routine maintenance.

[jack14r]

Paul,the most important thing is that you had spare filters with you,or as I call it "INVENTORY"

[phorner]

You're right, Jack.

My routine is to always keep an inventory of belts, filters, fuses, relays and bulbs. As they are consumed, I replenish the inventory.

Sure saved by butt this time!!!

[merle&louise]

Paul,

Although it looks like your problem is solved, I had a similar situation and it was a bad fuel solenoid. I changed it and the problem of "bogging down with a load" disappeared.

Glad your filter change did the job.

[phorner]

On my return trip from the Oysterfest, I decided to run my generator and CruiseAirs while driving the bus home. Although I was confident that changing out my fuel filters had solved my problem, I wanted to test the system.

As it turned out, changing the filters did, indeed, resolve my problem.

However, you might recall that my original concern, as noted on another thread, was that my generator temperature seemed to be a bit elevated.

I kept a close eye on the generator temps today while driving and found it interesting to note that the temperature had now returned to "normal"... just under 180 degrees, about 178 based on my analog gauge.

So, when I first noticed that the temperature was ever so slightly elevated while dry camping in Perry, it was telling me something after all. Apparently, as the filters were clogging, the generator had to work just a little bit harder to do the job, resulting in slightly elevated temps. Not high enough to be a problem, but certainly not "normal".

The lesson I think that I can take from this is to keep an eye on all your instrumentation. Get to know what is "normal" for your bus. When the gauges start to move beyond what you know to be "normal" something is going on. It may not be immediately apparent, but you can bet that something has changed.

You should be able to make a quick scan of your gauges to know if all is well....... or not. You should be able to tell immediately if something is "just not right".

And, by the way, the generator running and 3 CruiseAirs pumping out beer cold air did the job just fine today......

[merle&louise]

Paul,

How many hours were on the fuel filters?

[phorner]

Tuga,

There were 91 hours on those filters when I changed them out, about 35 of which were put on while dry camping in Perry before they clogged to the point of failure.

Actually, failure isn't correct. The filters did not fail..... they did exactly what they were intended to do.

As a follow up, I inspected my Racor fuel water separator and found about an inch of black slime in the bottom, which I drained out. Most likely algae which had accumulated while stationary. I had added an algicide before parking the bus last December and I think that perhaps the additive may have contributed to the build up in all my filters.

[truk4u]

Paul,

You may want to think about changing out the Racor filter and I'll bet it's coated in slime as well. I had the same thing on my Liberty and when I took out the filter, it was bad with the black algae.

[mike kerley]

Just a thought, algicide is great for keeping alge from growing in fresh fuel, but if its already present, the algicide will kill it which will clog the filters faster than leaving it alone and burning the fuel. I've always been told to add it to fresh fuel, but never to old fuel. If the fuel is old and full of alge, have it cleaned first, then add the chemicals.