HI,
My 7.5kw generator stalls after running about 5 min. It then begins to run rough. According to the manual, I need to replace the lp propane filter. There are no pics on the internet including on the Kohler website. Does anyone have any info on how to do this? Thanks,

Rick

I don't have any experience with Kohler LP generators but the Kwyatt is what I have.

I had similar problems and found that it was the Beam regulator was all gummed up with oil that comes along with propane. I rebuilt the regulator and it is now good again. Supposedly I needed special tools and measuring equipment to set up the regulator but all I did was replace the diaphragms and needles and seats, didn't change or adjust any springs.

I found later that you can by a new regulator for about the same cost as a rebuild kit.

I don't have a filter so I cannot comment about that.

I am having the same problem with our Kohler and but don't have a manual..hope somebody has some ideas on what needs to be fixed and a source for the parts needed.

I have a good friend that is in the small engine/generator repair biz and has a complete library of Kohler and more.

I will check with him for you if that would work.

The engine could be balking for other reasons, as well. Such as loss of ignition.

Is the plug fresh and gapped at .018" ?

Sometimes a coil will fail when it gets warm. This could be checked by rigging up an NE51H lamp in series in a piece of plug lead to make a tester in the spark lead. you can use regular wire if you keep it away from metal. This would check for spark.

Sometimes part of the protective circuitry can cut off the 12 volts to the coil. Such as overheating, low oil pressure, etc. Or a rogue relay could be doing it. Kohlers run the ignition through a lot of relays. A hot light on the coil + terminal would tell the tale. Or, a jumper from the hot term on the start solenoid to the + on the coil would eliminate that possibility for test purposes by bypassing the protective circuitry.

An engine can balk when warm if expansion has caused a leak in the intake to open up.

My Kohler genset is a 7CKM21 powered by a K-582 engine. I can also offer a copy of the operating manual. I can send wiring diagrams if that will help.

quote:

Originally posted by bill h:
The engine could be balking for other reasons, as well. Such as loss of ignition.

I have a little more info - I talked to Rick yesterday and he stated that the regulator was "Frozen". According to Rick - the manual said a frozen regulator was a sign of a bad filter.

Could bad circulation of antifreeze occur to the regulator, then it would also freeze. I also had problem with my Dometic (would not start)in which the regulator was contaminated with oil: problem solved after replacing it.

Mike

Hi,

The regulators are brand new and were professionally installed by a Kohler technician. I will try to get the filter changed in the next few days. I'll keep you posted. Thanks for the info.

Rick

since my Kohler 7.5 didn't come with a manual, it would be helpful to me to view a diagram of the plumbing that is involved to get the propane to the carb of the generator. Is the filter separate from the regulator? If one is contaminated with oil is the other too? How accessible are both for servicing? Does generator have to be dropped to do this servicing? Boy, you can tell I don't know much about this!! I can use all the help I can get.

I'm going a bit from memory, since I replaced the Kohler with a gaso-powered Honda.

First, no, the genset doesn't have to be removed (and from experience, I can attest, that's a Very Good Thing).

My Kohler didn't have a filter. There was a regulator on the propane tank, and another on the genset. I really have to wonder if any LPG genset would have a filter, as there is (speaking as a recovering fuels/lube engineer) no need for one.

LPG (as well as natural gas) does come with lower ends (larger molecules of hydrocarbons) imbedded. Some may be large enough to clog the regulator, and the filter, if there really is one.

Actually a propane filter would be a separator, discarding the lower ends into a bowl. One wouldn't expect to find a screen-type filter in an LPG run.

Your issue does seem to be one of fuel flow, however, so I think you're on the right track. I suspect the regulator. If the stove and furnace run properly, the one at the genset is the rpime suspect.

Going off ancient memory. I had a 7KW Kohler propane powered when we had the bus. Fed it with a 60 gallon tank so it worked pretty good. Ran liquid out of the tank directly to the evaporater, filter and yes it would sometimes freeze up. Learned to live with it.

The evaporater/regulator was mounted on the cylinder head. The reason was to keep it warm. When the weather was cool I used to run the genset for about 15minutes before putting much of a load on it. Needed to get the head warm Once the engine was warmed up I never had a problem.

Now propane has an oil added to provide ordor. If you only do short run times the oil will accumulate in the evaporater. Sometimes you can just get things warmed up, put a good load on the genset and let it run for about 4 or 5 hours. This will tend to get the oil out of the regulator.

There is no carb, just an orfice that is adjustable with a wing nut type control. Sometimes this may need a tweak.

so let me get this straight...my Kohler may or may not have a filter...to fix the problem of genset running fine on startup and with load until it starts to stumble after 10 or 15 minutes...I should either clean filter if its there...replace the regulator with a new one or if not, run genset with load for up to 5 hours to clear oil from regulator. I'm now a little more confused than before.

It may or may not have a filter. Unlike gasoline engines which have fuel pumps, LPG engines rely on the pressure in the fuel tank. This is dropped down to around 10-15 psi at the carburetor. Since that engine will burn over 1 gph, and it runs for 10-15 minutes it doesn't sound like a filter problem, as there's not enough gas in just the supply line to run it that long, and LPG is far less susceptible to impurities than gaso.

I just don't think that mercaptan, the odorizer, would have anything to do with the problem, as it mixes well with gas, and is only there in a few
parts per million. Heavier ends in the gas may have gummed something up, but again, I don't think there would be enough - they're found in natural gas, but LPG is processed more.

That all points to something like a regulator gradually closing down - an internal leak, perhaps? Or if there's water in the system, an orifice could be icing up, which would more liekly be the main one, which regulates all the house propane fittings.

Did the genset run alright for a while after the replacement regulators were installed? Getting a bad one isn't unusual. Usually when replacing regulators, a technician will flush the lines; do you know if that were done?

Richard's post was about having his regulators replaced...I have yet to do anything as I'm trying to isolate the problem. After about 15 minutes of running under load my unit starts to stumble and I can smell propane from the exhaust.

Missed that. Propane smell indicates either a too-rich mixture (carburetor, or more likely, regulator) or a spark problem (Coil failing when it gets hot).