Old kohler generator

bassmaster17327 · #1 09/16/13, 03:59 PM

I was not sure where to post this so I understand if it is moved/deleted.

I purchased an old generator from someone on craigslist, it has a 8hp Kohler (1970's?) and says it is 750 watts. It can start off a battery but the charging system to recharge the cranking battery is not working, the 110 volt side seems fine. I have read that you have to be careful about running electronics from a generator because of power surges, would I be safe to run a television or radio off of this? Has anyone used a generator like this before? It has two tags on it one says "Kohler electric plant" and the other says "Kohler emergency plant", 8hp seems big to run a 750 watt generator.

Ozarks Tom · #2 09/16/13, 04:19 PM

If you're concerned about power surges, use surge protectors. I wouldn't really think it would be a problem though. My backup generator is only 4000 watt, and has an 8 hp Tecumseh engine on it.

Grumpy old man · #3 09/16/13, 04:37 PM

Your not going to run very much with a small generator and feeding an 8 hp to get 750 watts is not good , I'd love to have the Kohler engine tho but many of the generator based engines have a tapered crankshaft and it can be a pain to find a tapered pulley for them if you wanted to re purpose the engine . Now with the overhead valve engines you can buy a 6500 to 9000 watt genny for 6-900 dollars and run your whole house on the same gas as that 750 watt and have electric start .I've noticed when pricing them they generally run a $100.00 per 100 watts new and about 1/2 that used . some equipment I always look for the older models like troy bilt horse tillers but when it comes to a generator some of the new stuff is pretty good .

Johnny Dolittle · #4 09/16/13, 04:58 PM

8 hp Kohler is usually a 4000 watt generator. I do not think that engine is 8 hp if the generator is 750 watts. Is there a model number on a tag riveted to the engine?

The shroud on that Kohler looks more like a 1950's engine.

That engine looks small when you compare it to the receptacle box.

I'm thinking you might have a 2-3 hp engine

bassmaster17327 · #5 09/16/13, 05:00 PM

I understand that it will use a lot of fuel and not run very much but I really did not buy it to be really useful, I bought it because it was 30.00 and I like old engines. I figured since I have it I might as well try to use it a little if we loose power, generally we loose power once or twice a year and it is usually back on in a couple hours.

It says 750 watts but I was running a disc grinder off of it and I always thought they were around 1,000 watts

Grumpy old man · #6 09/16/13, 05:04 PM

funny how the old equipment is still around and the new stuff might not last a few years ! I would have grabbed it for $60.00 I like the old stuff too.

bassmaster17327 · #7 09/16/13, 05:08 PM

Johnny, I think you are correct. The guy told me it was 8 hp but the metal tag says 1.9, it looks older than the 1973 10hp on my gravely. The whole unit is unbelievable heavy

bassmaster17327 · #8 09/16/13, 05:11 PM

This is the tag, the 1.9 does look like 7.9 so maybe that is how he got 8hp

Johnny Dolittle · #9 09/16/13, 05:19 PM

Typically the watt number begins with a digit that is 1/2 the hp

10 hp is a 5000 watt etc (continuous watts)

12 hp is a 6000 watt etc

But newer generators are now more efficient. I have a 9 hp Briggs Vangard running a 5000 watt generator.

Some of these cheap imported generator exaggerate the watts or give the start up watts and not the continuous watts

bassmaster17327 · #10 09/16/13, 05:21 PM

I used to have a new generator that was 5,000 watts and ten hp, that's why I thought 8hp was too big for 750 watts. I still would have bought it for 30.00

joebill · #11 09/16/13, 07:49 PM

That old kohler will likely outlive us all. maybe not the latest or most effiecient, but a set of rings every decade or so and clean the points and it will just go on chugging away.

Surprisingly, many new gernerators are called "emergency generators" for a reason. Some of those engines are rated at 100 hours of life.

I'd say you found a winner.....Joe

biggkidd · #12 09/16/13, 08:04 PM

Those old gensets were way under rated too. I know this for a fact. Either way other than being hard to get any needed parts for it is a keeper. I doubt that old of a unit will have any kind of safety fuse or breaker. So you may want to add one. I would think about 10 amps at 120 volts would leave plenty of margin for error. Most 1000 watt gen today have a 2.4-2.6 hp eng with a 8 amp breaker. As far as the 12V side you may want to pull the flywheel and clean up the stator there as its most likely dirty and the cause of your dc power not working or may not be hooked up.

Good Luck Enjoy

Larry
A World Away

Rectifier · #13 09/16/13, 09:26 PM

Bad ass! Motors and generators are my trade. Those old gensets are tanks and will never quit. I personally own one (Onan) that I got for free because it was submerged in saltwater, diesel engine and all. After washing and baking the generator head and flushing out the motor, it ran on the first crank and produced perfect voltage. One tough machine, but it is so heavy that you can't move it an inch without an engine hoist and dollies.

Many of these guys, depending on the exciter, will produce a nice clean sine wave that is far safer for equipment than any of the junk generators you can buy today. Lots of copper, big cores, they can also handle huge surge loading without burning up.

However, you can get a "power surge" if you bog any generator down with a big load, it can over-rev as the governor compensates, or as the load is removed. So if you are running electronics, keep that in mind.

I like to run my emergency electronics off of rechargable batteries though, as their draw is so low that they will waste tons of fuel idling the engine. All the idling is bad for these engines as they are designed to run hard, especially old diesel generators. They will coke up.

Congrats on a great find, I would gladly have bought that for the $30, handy portable power, you can run a lot of tools, lights or even electric pumps with 750 watts, and fuel consumption will be decent as you aren't using a bunch of displacement you don't need for the job.

fordy · #14 09/16/13, 10:03 PM

..............Invest in a Kill A Watt.....~$25 or so.........it will tell you volts , amps , watts , frequency and kilowatt hours !
..............1 Hp will produce 746 watts , so 8 Hp =5,968 watts.......I can't imagine they would use a 8Hp motor for a 750 generator ! Something is out of Sync in my opinion ! The Kill A Watt will tell you very quickly how stable the voltage is from the genset when under a load ! , fordy

Jim-mi · #15 09/16/13, 11:13 PM

. . ."Oldy but goodie"
It the voltage regulation is in question, than use it to run a transformer type battery charger into a couple golf car batteries and then run your stuff off an inverter.

Suggest you find some REC gasoline and use that . . . . . so that you don''t have to worry about a carb full of varnish. after it sits for a while.....

I'll give ya $40 for it . . . . . . . . . . . .lol

Old Vet · #16 09/16/13, 11:32 PM

Quote:

Originally Posted by Jim-mi

. . ."Oldy but goodie"
It the voltage regulation is in question, than use it to run a transformer type battery charger into a couple golf car batteries and then run your stuff off an inverter.

Suggest you find some REC gasoline and use that . . . . . so that you don''t have to worry about a carb full of varnish. after it sits for a while.....

I'll give ya $40 for it . . . . . . . . . . . .lol

Why it only puts out electricity for old days days. You cant run modern gadgets now on old electricity.