RV generator

[F4 pilot]

My Kohler 2.5cmz has died. Has anybody tried the new hand carry type of generators such as a Bolly, yamaha,Honda etc? Maybe install it on a rear carrier that fits into a trailer hitch? To install this type of unit in place of the original would be a problem for cooling as they are not designed for a small compartment.

The available selection for our small Class C is very limited.

Any ideas?

F4 pilot

[motoyhomme]

Sometime ago I had posted this to someone's question similar to yours F4 (located on General Discussion titled "Generator"):

A couple of years ago, I saw a Toy house with a bumper generator set up that was the cleanest combo I have ever seen. The owner had a 7.5K btu AC and had installed a toolbox on the bumper. It was the polished aluminum like a lot of pickups have in the bed, except it wasn't that large. It had an L shaped lid that opened up the top and half way down the side facing the rear (I later saw that same box at a Tractor Supply Co store). A 2KW Honda fit down inside and was latched somehow. He had constructed a simple exhaust pipe that inserted into the exhaust of the Honda and was passed down through the box and outside. You couldn't hear it run. He had cut a hole for intake air in the bottom of the box. The power cord from the MH was kept plugged into the generator or it could be removed for shore power. A 12 volt automotive fan was attached to an exhaust port he had cut in the box. It was kept plugged into the 12 volt outlet on the Honda. The lid was unlocked (padlock), raised, and a quick pull of the starting cord was all that was required. The exhaust fan started as soon as the generator did. Close the lid and turn on the AC and take off down the road. To refuel, he just opened the lid, unplugged the cords, slid the exhaust pipe over, unlatched, and removed the generator. It was easier and safer to refuel out of the box. I was really jealous of his ingenuity. I would have went for it if I could have found a 7.5 KW A/C, I don't know about the 9 KW. The 13.5 KW A/C that I have is too big for the Honda 2KW generator. I don't have the space for a compartment on my Sunrader to mount an Onan or anything else.

Good luck on your generator quest.

Allen

[McShank]

I have a Kohler 2.5 that wouldn't start. I removed the carb and had it cleaned, started right up and runs smooth. Only problem I have now is that I cannot find the metal plate which mounts on top of the carb and intake manifold and secures the air filter and choke cable. If your 2.5 is heading for the junk pile would you part with that mounting plate?

McShank

[fighterpilot]

I have used the Honda 2000 on a rack I built to insert in the trailer hitch. Worked great. Make sure 2000 is enough to do your work however. I note you had a 2.5 before. By the way F4 pilot I am an old Navy F8 Crusader pilot-- which service were you? Ray

Edited June 29, 2008 by fighterpilot

[thepager5]

Heres' what I have . . .

It's a Coleman Powermate 2500 max watts. (kinda LOUD but not used alot - its just for emergencies or at a rest stop) I Purchased it on Ebay for $165 new in box. It is @ 19" X 19" by 24" tall with an extension handle. I mounted it to the tray with 3 pipeclamps and a lock and chain.

It runs the A/C by itself (with nothing else on) or it runs lights and microwave and electric grill with no problem.

My generator is mounted on the rear cargo tray.

PICS

Just drove 3079 miles and no problems with either the tray or the generator.

Pager

Arkansas

[sdboltdude]

I want to do your generator setup on my 1987 mini cruiser

[Nam]

Onan 2.8KW will fit on the Kohler's compament. Used one runs for about $800 if you can find one with low hour.

[straygoose]

Onan 2.8KW will fit on the Kohler's compament. Used one runs for about $800 if you can find one with low hour.

There was a Kohler 2.8 on EBay today for, I think $1650, if anyone is interested. I think it was new. Even if it is, its still more than I want to spend.

[straygoose]

Man, its too bad this guy opened the thread four years ago. I would have offered him some money for that gennie carcass. I coulda rebuilt that thing and put it in my GV.

[Ritabago's Dad]

I'm looking for a replacement carburetor for the Kohler 800 2.5 CMZ. There's no part number listed in the service manual; can anyone lead me in a good direction to search online? I'd appreciate it!

[Skydancer2992]

According to the service manual, Page 8-1, the engine is actually a Tecumseh TVM140 6HP.

I'm looking for a replacement carburetor for the Kohler 800 2.5 CMZ. There's no part number listed in the service manual; can anyone lead me in a good direction to search online? I'd appreciate it!

[Derek up North]

Playing with Google, it appears that the Kohler 2.5CMZ uses a Tecumseh TVM-140 engine. Googling more, it seems the Tecumseh TVM-140 uses a "Genuine Tecumseh Carburetor 632233A, fits certain TVM140 engines ..."

http://www.ebay.com/itm/Genuine-Tecumseh-Carburetor-632233A-fits-certain-TVM140-engines-/121050255057

Like everything else on the Internet, this might be accurate information!

EDIT:- Maybe a little rebuild kit?

http://www.discountonlineparts.com/lawnmower/?c=Carburetor%20Parts&sc=Rebuild%20Kits&b=Tecumseh&id=3557

[5Toyota]

THOSE LOOK NO DIFFERENT THEN THE CARB ON MY SIX AND A HALF H P TECUMSEH LAWN MOWER

[Ritabago's Dad]

Thanks guys - I actually do see that in the service manual (page 1-1 in mine) but still no part number for that carburetor. Searching for Techumseh vs. Kohler is yielding better results though. So, technically speaking, I should be able to run a roof air unit (13,500 btu) that requires 115 VAC, 60 hz 1 phase power since the Kohler puts out 120 V., 1⦱, 2W?

Thanks again - this stuff is getting easier. : )

[Ritabago's Dad]

It's alive! Bought the above listed carburetor and had it installed at my new favorite RV shop. The generator has never run since I've had my Toy (going on 2 years) and the guy who owned it before me doesn't remember the last time that he ran it. (There are only 29 hours on the unit!) In any case, it's running my roof air and charging up my battery charger right now. Thing is, it's doing some alternating from high to low revs. Not quickly, just every now and again, it'll act like it's straining, and then rev back up and hang out there like a champ. I've been adjusting and fine tuning between more air and more gas, trying to find a place where it will handle a load steadily. Any suggestions? Small moves or large ones? Any primer on which direction to go based on how the motor is acting? Is it just shaking off a lot of crud? When it gets bogged down, there is some black smoke, but exhaust is clean when it's really revving.

This is my first generator, period, so I appreciate your advice. At this point, I'm just stoked that it's powering the coach and not shutting down!

[90toydolphin]

maybe your frig is on and when it starts it causes the gen to increase rpm's? could also be the airconditioner cycling the compressor off and on? just a couple of thoughts.

[Ritabago's Dad]

My fridge isn't currently working (that's next to fix) - the a/c makes sense, thanks! Right now, I've got it on low cool and it ran at a nice, constant speed for about ten minutes, then began slowly surging. It's not dropping into low-low rpms right now, but it is rising and falling. The tech said that the oil was still good after putting in the the new carb and spark plug. Is there some sort of gas reserve inside the gennie? I've got a fresh tank of gas and have run the generator for about three hours since it got up and running yesterday. Is it just a matter of running out the bad stuff?

BTW - if anyone wants the old carburetor, I'll ship it out for $5. Maybe there's something on it you can use?

UPDATE/EDIT - I backed off the idle screw about a quarter turn to the right and it's been merrily humming along at a nice, consistent clip. Do you ordinarily need to adjust the rich/lean mixture that much in order to keep it happy? After about 40 minutes of smoothness, it began to surge occasionally, slowing down almost enough to "break", and then powers back up. I turned off the roof air and left on the lights - now it's doing fine. Does that sound like compressor activity? Any thoughts on Sea Foam?

[5Toyota]

the compresser goes on and off the fan runs cont the governer on the gen adjust eng to load

[fred heath]

Have you changed your air filter?

I had the same problem with mine. Even though by filter looked good, it was the original. I changed it and the problem went away.

[Maineah]

The generators are designed to run at 3600 rpm so that is what the governor is trying to maintain. At 3600 it produces 60 cycles ac at rated voltage around 117 volts. When it takes a high current hit from the a/c it does it's best to stay at 3600 and will slow down when it is trying to recover. They won't slow down to idle like an inverter generator because they are trying to make 60 cycle ac and the only way they can do that is at 3600 rpm. When I adjust generator speed I use a frequency meter and adjust it to 60 cycles. So yes it is normal for them to slow down under heavy loads like an a/c cycling at that point the engine is pedal to the metal trying to run at 3600.

[Ritabago's Dad]

I'm waiting on a voltage meter so I can check the output. As it turns out, the choke cable was getting stuck; I started having difficulty getting the choke lever to push back in. Finally, I adjusted it from the carburetor and that seemed to iron out the idle, but it seems awfully intense and noisy. I did, by mistake, get the throttle lever pushed all the way to the left and it really sounded like it was about to take off, all the lights got brighter than I'd ever seen and the engine temp soared. I quickly shut it down and returned the lever to where it would be if the choke lever was all the way in.

By the way, what do you recommend to use for cleaning the exterior of the generator? It's caked with dirt and grime, which has been burning off and it creates additional fumes/odor/smoke.

I will be ordering a new air filter - wondering if I should do the same with the fuel filter?

Thanks, guys!

[Ritabago's Dad]

I took it back to the tech and he noticed that the control arm for the choke had moved, probably from me pulling too hard on the choke lever. I had also overfilled with oil, which was causing the smoking. Told him about increasing the rpms and he said if it still fired up, there was no problem there. Ultimately, after an oil change and a bit of cleaning, it fired up nicely, though some oil was blowing out of the carburetor intake manifold gasket. He quickly identified that as the reason that it wasn't holding steady, because of the air escaping (so maybe overfilling was a good thing?), so I'm going to go hunt down a set of gaskets and have him install those.

Thankfully, this guy lets me watch him work so I can understand how to do it myself. As usual, thanks for all the help on this forum as well.

UPDATE: Found this great parts site for the Tecumseh TVM140 - http://tinyurl.com/a68dhop

[stamar]

I am still on the often used 2000 watt tote outdoor generator project

Using a common slide out storing it in the generator compartment.

again sometime near summer.

Id like a honda or yamaha. Im all about made in japan actually I love it. Well see whats in the budget.

[zero]

He quickly identified that as the reason that it wasn't holding steady, because of the air escaping (so maybe overfilling was a good thing?), so I'm going to go hunt down a set of gaskets and have him install those.

Thankfully, this guy lets me watch him work so I can understand how to do it myself. As usual, thanks for all the help on this forum as well.

UPDATE: Found this great parts site for the Tecumseh TVM140 - http://tinyurl.com/a68dhop

I was kind of surprised to see a TVM being used on a genset. No insult intended, but they were not very good engines. After Tecumseh/Power Products when bankrupt, the market was flooded with brand new TVM for $120 each, complete.

Does your model have an adjustable main jet on the carb or it is a "fixed" jet? I ask because the versions with a fixed jet are very touchy. The governors will act up and "hunt" with changes in fuel octane, atlitude, slight air leaks, restrictive air cleaners , even when NO air cleaners are on and there isn't enough resistance.

With some the best long-term fix is to install an adjustable main jet. When an engine (especially some Tesumsheh's) run lean, the governor will 'hunt", that is surge back and forth.

[DanAatTheCape]

I use a honda 2000i to replace my kohler. I was able to cut the baffles out of the gen box & using the parts that attached to the gen to extend the box & it was just tall enough to carry the honda.

quite happy over all.

[Nam]

In moderate spring temperature, the Honda i2000eu actually runs my 13.5k btu roof air with no problem. I am not sure when the temperature goes up, would it run or not.

[Maineah]

In moderate spring temperature, the Honda i2000eu actually runs my 13.5k btu roof air with no problem. I am not sure when the temperature goes up, would it run or not.

As the temp rises so does the head pressure on the A/C it's best that you don't try to run it with a 2000 watt unit for it and the generators sake. Some have tried bigger start caps for the compressor but it still is right at the max no matter what.

[Ritabago's Dad]

I was kind of surprised to see a TVM being used on a genset. No insult intended, but they were not very good engines. After Tecumseh/Power Products when bankrupt, the market was flooded with brand new TVM for $120 each, complete.

Does your model have an adjustable main jet on the carb or it is a "fixed" jet? I ask because the versions with a fixed jet are very touchy. The governors will act up and "hunt" with changes in fuel octane, atlitude, slight air leaks, restrictive air cleaners , even when NO air cleaners are on and there isn't enough resistance.

With some the best long-term fix is to install an adjustable main jet. When an engine (especially some Tesumsheh's) run lean, the governor will 'hunt", that is surge back and forth.

Would an adjustable main jet be indicated by the "main fuel adjustment screw" on the bottom of the carburetor bowl? If so, it appears that I can adjust it.

It runs fairly good, considering the air leak, but at 2500 watts of output, it seems pretty overworked in trying to power even the roof air without the compressor running. According to the manual, "minor adjustments may have to be made with the engine running at full load to achieve maximum power." My only concern is doing some kind of damage to the roof air because of low voltage while I make the adjustments (kicking on the roof air alone drops the voltage from 120-126 vac to 92-96 vac.) After adjusting the main fuel adjustment screw and then working with the fuel adjustment and idle screws, I still can't get more than 96 vac and, when I shut everything off, it's cranking 144 vac with no load. How big a role does the air leak play in this drama? And, since the only thing receiving juice is the coach battery when I start the gen, is 144 vac going to do any damage? When I turn on the roof air (no compressor), the meter reading drops to 122-126 vac.

[Maineah]

Yes it often is call an altitude adjustment on an RV. What is with the air leak? There is not much there to leak but if it is it's got to be fixed first. If you have an air leak it most likely won't run worth a hoot. Your wild voltage swings kind of points to a governor issue. It should not run the voltage that high the governor should drop it back no load same as it should deliver 117 volts loaded but only if it is running properly in the first place. The Kohier units were not any where near as well built as the Onan's but it still should stay pretty close in voltage output. So to answer your question no you should not run the charger/converter at 144 volts. A 300 watt work lamp would be a pretty good load to adjust your carb it can ballast your system and protect it from over voltage. The generator output is totally dependent on engine RPM so the engine has to run properly in order to accomplish that.

[Vanman]

Our Onan 2800 microlite will run the microwave and AC at the same time, my AC doesn't use near the microwaves current, guess it's a small one.

[zero]

Would an adjustable main jet be indicated by the "main fuel adjustment screw" on the bottom of the carburetor bowl? If so, it appears that I can adjust it.

It runs fairly good, considering the air leak, but at 2500 watts of output, it seems pretty overworked in trying to power even the roof air without the compressor running. According to the manual, "minor adjustments may have to be made with the engine running at full load to achieve maximum power." My only concern is doing some kind of damage to the roof air because of low voltage while I make the adjustments (kicking on the roof air alone drops the voltage from 120-126 vac to 92-96 vac.) After adjusting the main fuel adjustment screw and then working with the fuel adjustment and idle screws, I still can't get more than 96 vac and, when I shut everything off, it's cranking 144 vac with no load. How big a role does the air leak play in this drama? And, since the only thing receiving juice is the coach battery when I start the gen, is 144 vac going to do any damage? When I turn on the roof air (no compressor), the meter reading drops to 122-126 vac.

Yes, the "main adjustment" screw is an adjustable main-jet. It can use tweaking according to altitude, fuel octane, air temps, etc. I doubt it's your problem though.

If the engine runs smoothly when under load but you've got low-voltage - you need to check how fast it is running. A hand-held vibration tachometer is what it often used. Then can be found for $10-$15 or borrowed (maybe from a small-engine or chain-saw shop). Very simple device that fits in the palm of your hand.

With most non-inverter generators - voltage depends on RPMs. The faster the engine runs, the higher the voltage but also the Hertz cycles change. In your case, having perfect 60 cycles does't matter much. If effects clocks keeping time but little else.

Your generator ought to run at 3800-3900 RPM with no load on it. When you put a full load on it, it should drop to no slower then 3600 RPM.

If you find it's slow, adjust the governor. No load voltage at 3800 RPM should be 125-130 volts. When under load at 3600 RPM the voltage should be 118 volts and never lower then 108 volts.

If when under full load - you find the RPM to be correct but the voltage below 108 volts -then you either have too much load, or the generator is not making proper output. If the latter, it's time to check the regulator, brushes, etc.

If you have a portable watt-meter - it would behoove you to hook it to your AC unit and see what it draws when the compressor kicks in. My "Kill A Watt" unit cost me $18 and it's great for this sort of quick check.

[Sunrading Arkansas]

OK, since I'm keeping my AC I've started a search for a generator that can run it. It's a Dometic Duo-Therm (I believe 13500, but can't find any documentation). Just ran accross this one on Homedepot's website

http://www.homedepot.com/p/Ryobi-2-200-Watt-Gasoline-Powered-Digital-Inverter-Generator-RYI2200/203617901#specifications

Seems like a good deal, and has decent reviews (although it's ugly as sin). Just wanted to see what everyone thought as far as this being adequate for running the AC (only)....I've read plenty of favorable&unfavorable experiences with a honda 2000/ 13500 combo....so I'm hoping the extra 200watts on this one would tip the scale....please let me know what you think.

Thanks,

Patrick

[zero]

I think you need to find someone who has actually tried it. One downside to the DC to AC inverter generator is the low surge rating with many. The up-side is - the AC power is usually cleaner with better wave peaks and often beat AC-based generators with motor starting.

I was at a Home Depot parking lot sale a few years ago when they were selling Honeywell 2000i inverter generators for $399 each. I met several RV owners who said the generators worked great with their roof-top AC units. i don't know what size the AC units were however.

It would behoove you to run an amp-draw test on your AC unit and see how much the start-up surge is in amps and for how long before it settles down. Chances are - if it draws over 15 amps @ 120 VAC for more then 5 seconds - that generator will probably trip and shut down the AC.

You can also buy a fairly cheap capacitor kit to cut down on the start-surge on your AC unit. That allows smaller gensets to be used. Many of the newer roof-top AC units for RVs leave the factory with the low-surge cap-kits already installed. I don't know what you have.

[Maineah]

Well I'm going to tell you about the Ryobi I bought one on sale at HD I have never seen any engine leak oil as badly as it did. I ran it maybe 20 min. and it left a nice puddle of oil on the garage floor and dripped oil across the parking lot and the floor at HD when I took it back for a refund. That is one of the complaints about them if you run a check on line. It was quiet while it ran but no doubt it was not a Honda or a Yamaha.

[Sunrading Arkansas]

Thank you both for your input and advice, always great. I'll check the amp draw and if it looks feasible to run with a Honda 2000i I'll bite the bullet on a "pre-owned." Otherwise I'll just pay for hook-ups the few days a year we'll need the AC. (Because a 3k is not worth it to me)....or maybe I'll just get a cheapo Champion and deal with the extra noise....