Short version.
At work we have an old generator from the early 80s in the basement. It can no longer be used for backup power at work because inside building + combustion engine + new laws = not allowed. It could have been grandfathered if we had kept up with the yearly inspections, but the last inspection entry was from 1992. As far as I could tell from the paperwork, the generator was installed in 1982, and the Kohler engine has 22 hours on it.
8hp, 3kW, 120/240v.
It is currently hooked up to the building's natural gas. I want to rip it out and convert it to propane for at camp. Googling says that the low-pressure gaseous carb kits are the same part number regardless of LP or NG. Can that be right? Wouldn't there be a different orifice or metering to maintain stoich between the different fuels?
Is it really just as simple as hooking up an LP tank and done?
The other thing is... what might this be worth? I want to buy it from work for my own personal use, but I have no idea what is a fair price to offer. The boss would likely tell me to just take it, but if I weren't buying it, I'd be selling it publicly to make money for the theater. It's an asset and we deserve to make money off it.
A 3kW generator can be had new from the hammer store for cheap. The conversion doesn't add any value.
If it runs, might be worth 50 to 100, max, probably less.
3k will run some lights, probably handle the starting load on a refrigerator at the same time.
Yep, that old beast is a beast, and will run forever, but because it's probably loud AF it's somewhat worthless given today's crop of quieter-running units.
I picked up a Champion gennie from Tractor Supply on sale for $225 a few years back. It's rated at 3500 Watts or so- enough to handle the starting load on my well pump. We use it maybe once a year when the power goes out so we have running water.
In your case, if you wanted a gennie, that's what I'd do. And just run it off gasoline.
If I had a gas generator, I would likely convert it to propane anyway. This is for two months in the summer, and only would run anywhere from 0-4 times per summer when the power goes out. I would hate to get there every year and have to pull the bowl on the carb, or fight with a bout of condensation in the tank, etc. Propane doesn't have those issues. This one hasn't run since 1992 and it started on the first pull. I certainly don't see the value in this situation of converting TO gasoline.
We pack in most of our food for the summer since it's out in the boonies, and it would be pretty tragic if the power went out for a few days and all of our food spoiled. I'm planning on putting in a "cutout" breaker to switch over the panel (safety first) to the generator. The most we would feed is three circuits (one of each of our three campsites), and the only thing we would be running is two small compressor fridges. The third campsite has a propane fridge that will ignite on DC power from the onboard battery, but the most they would draw would be the small DC charger/converter and a few LED 1141 bulbs. I think 12A is more than enough. It's not like we'll be running A/C, three plasma TVs and a dishwasher. This is basically to save the food.
Yes, I understand the carbs are the same on NG vs propane application. But there is a regulator-looking thing on the unit that needs to be flipped or something.
My generator is a generac that I bought used and set it up for NG on my house. The guy I bought it from was a generator tech and bought units from his clients replacing them and refurbished and sold the used units. He was able to show me it ran before we loaded it in my truck. How? On a bottle of propane... I actually don't think he even made the changes, but they are laid out clearly in the generac manual available for my model on the generac website. I just confirmed it was in ng setting when I installed it and didn't have to change it.
Keep in mind: many old generators are built for slightly higher pressure ng than the now common home service 1/4psi or whatever. I was worried about this but I heard that mostly it just affects starting. The recommendation I got was to oversize the line to the generator and to make sure there was ample volume of gas available for startup, but once running the vacuum would draw in enough to make up for the difference in line pressure.
Thanks for the tip on pressure. I'll take a look at the regulator thingy and see if it specifies a pressure or a range.
And I lied. Now that I looked at the picture, I see it has 28 hours on it.
I found the owner's manual online, but it just talks about gasoline carb settings. The only mention of gaseous fuel is one asterisk on the plug gap section of the specs. The asterisk footnote says "plug gap .018 on gaseous-fuel models." I didn't find any information on NG or LP.
Sounds like it may be a light plant, as in emergency lighting and not meant for electrical appliances or auxiliaries.
Was it wired into a transfer switch?
No transfer switch, but (as I learned digging a little deeper and found more documentation) I found maintenance reports dating back to 1972, and the panel it goes to has glass fuses in it. It might be pretty old. The building was erected in 1953, but it isn't that old. The wiring coming out of it is THHN with a more modern jacket. Let's say it was installed between 68 and 72. That's my guess. I only mention that because it was likely installed before an automatic backfeeding prevention switch might have been mandated. There is a regulated power supply on the wall that keeps the batteries charged, a switch that says "auto/manual" which I assume is to tell it to start when it sense the power is out.
However... The labels in the fuse box suggest that it was just for emergency egress lighting, so no transfer switch would be required anyway.
So, yes. Light plant. 8hp, 3kW, 12.5A, 120v/240v
I think that serial number specs that kohler as a 1945 unit.. the 0945 is a dead giveaway... However, I could be wrong and kohler looks to have maybe reset the serial numbers at some point. Dig around Smokstak for more. https://www.smokstak.com/forum/showthread.php?t=155144
I'd go buy harbor freight at this point and let this one go to a restoration/old engine person.
The serial was from the genset. I have yet to find the serial on the engine.
Robbie.... does this help with determining NG pressure it will need? Looks like 6oz and max 8oz? That doesn't indicate pressure, unless it is short for ounces per square inch or something.
Offer to uninstall it and haul it off. WIN! That thing will run forever. Edit: Oops, missed the part about helping the theater. Wouldn't $100 or so be fair?
Ok, finally found the engine serial. It is 9275347.
If it follows standard Kohler numbering, that means the first digit is the year... which suggests 1977... but the very first maintenance log was 12/26/1971. I didn't see any engine replacement in the logs.
I signed up over at SmokStak, but it takes admin approval.
Edit.... found a factory service manual online. Serial beginning with 92 = 1978. At least the engine is a 1978. No idea about the genset, but with only 22 hours on it and all of the paint still flawless on all the bellhousing bolts, I'm guessing it is an unmolested 1978 unit. Perhaps they upgraded in 78 and there was a different unit there before that?
NermalSnert said:
Offer to uninstall it and haul it off. WIN! That thing will run forever. Edit: Oops, missed the part about helping the theater. Wouldn't $100 or so be fair?
I think it would be but I'm just unsure. I see these exact models on ebay asking $1500, but I don't know how much they actually sell for. A lot of crack smokers on ebay.
Yeah I'd guess that is oz/square inch. Plumbers on here would know better but I think that is closer to the old standard and the new standard residential pressure is 1/4 psi or 4 oz.
Curtis said:
NermalSnert said:
Offer to uninstall it and haul it off. WIN! That thing will run forever. Edit: Oops, missed the part about helping the theater. Wouldn't $100 or so be fair?
I think it would be but I'm just unsure. I see these exact models on ebay asking $1500, but I don't know how much they actually sell for. A lot of crack smokers on ebay.
eBay has an option to search completed sales. Very useful for researching sale prices.
I found two on ebay. One at $1000 obo, and one at $1499 obo. Didn't find any completed sales.
Don't over-think it. If ebay can't show you any completed sales, it's likely that you would face a similar situation if you tried to sell yours on behalf of the theater. Allowing for all your (and other people's) time and effort to make a sale happen, if it ever would, I think we're back to the idea that giving the theater $100 for something they would tell you to just take is fair for everybody.
Curtis said:
If I had a gas generator, I would likely convert it to propane anyway. This is for two months in the summer, and only would run anywhere from 0-4 times per summer when the power goes out. I would hate to get there every year and have to pull the bowl on the carb, or fight with a bout of condensation in the tank, etc. Propane doesn't have those issues. This one hasn't run since 1992 and it started on the first pull. I certainly don't see the value in this situation of converting TO gasoline.
We pack in most of our food for the summer since it's out in the boonies, and it would be pretty tragic if the power went out for a few days and all of our food spoiled. I'm planning on putting in a "cutout" breaker to switch over the panel (safety first) to the generator. The most we would feed is three circuits (one of each of our three campsites), and the only thing we would be running is two small compressor fridges. The third campsite has a propane fridge that will ignite on DC power from the onboard battery, but the most they would draw would be the small DC charger/converter and a few LED 1141 bulbs. I think 12A is more than enough. It's not like we'll be running A/C, three plasma TVs and a dishwasher. This is basically to save the food.
I understand your concerns, and usage requirements. Honestly its a lot like mine- emergency use only, and very very very sporadically.
My new gas gennie has a fuel cutoff. To shut it off, I cut off the fuel and let the engine starve itself. No carb fouling that way. The fuel in the tank is treated with marine Sta-Bil. So it'll last a season no problem.
I wouldn't convert a unit TO gasoline, but if I were buying a new gas unit, I don't know if I'd bother converting TO propane.
That thing does look like a beast, and old. The number being tossed around seem to be about $100. For that, it might be fun to tinker with. And if the noise ends up being a problem, or if the power output isn't sufficient, you can always try a newer unit.
Good points.
Up at camp I have an 8x10 shed and I was going to build a little open-ended, lean-to doghouse on the one side for it to help with some of the noise and keep it from weather.
Talked with the "boss" (I put that in quotes because he's one of my best friends) and he said I should take it and if $50 or $100 shows up in the cash box, great.
Nice! On a related note: The people I work for have a 10 year old Generac back-up generator for their weekend house. I had the service people out to check on a no start issue and was shocked to see a Ford 5.4 Windsor engine when they pulled the cover. 10 years old with 35 hrs and it looked like new. It's supposed to start and run for 12 min. once a week (It does now) had it been doing that It would have only 100+ hours on it. There is no doubt in my mind that if this unit causes them any more irritation- it's out, "Replace it" So, I wonder how many good engines that have run on nothing but lpg/lng are out there that can be had cheap. Or, is the lpg/lng conversion irreversible?
as I'm reading this there's thunder off in the distance and it's brightish outside. Well except for the really loud crack/flash that bumped the power for just a split second. Must've been close. 
Man, i would be so tempted to do solar if you have any decent exposure at all. Nothing like a rattly-ass generator to completely ruin the camping experience, especially the camping experience intensified by all the power being out.
How much non-spoilable food do you need? The wife-unit and I went for four days on approx 45 quarts of fridge capacity and did just ducky and we were eating good.
