during the recent visit from Hurricane Irene i had no end of trouble getting my mom's Coleman Powermate MAXA 3000 generator started, and keeping it running.  like many "emergency use" generators, this unit gets started twice a year –– and in the meantime it sits in the back of a shed with a cover over it.  this 10-year-old unit's sole purpose in life is to provide enough power for the sump pump and fridge –– that's it.   my mom is 75, lives alone with a dog, and is more than able to do stuff for herself but PM on the generator is my responsibility.  

nevertheless –– although Stabil is employed with an every-time-the-daylight-savings-time-changes schedule for fuel swap –– honestly i thought the 10 year old unit would be more forgiving to me when it is raining 12" in 12 hours.  it was not.  fortunately, although she lives within sight of the atlantic ocean her power was only off for about 4 hours.  kudos to the line crews on the job that sunday afternoon.  there was no appreciable accumulation of water in her basement during the time the power was off.  with her power on, she lent the Coleman generator to my brother, who was subsequently out for 4 days.  since i also had power, and the Coleman generator was so problematic, i lent my brother my Honda EU2000i and put the Coleman up on my bench.

this 3KW generator is powered by a 5.5HP Tecumseh OHV engine.  Tecumseh made about 87 bazillion of these motors, in one form or another, for everything ranging from generators to rototillers to snowblowers.  the engine below is an OHH55 69069D, one of about 87 variants.

the starting/running trouble seemed to revolve around the carb, since the only way to keep it running was to press the primer bulb, and when it did run it hunted severely –– almost to a stall, and then back up in RPM, repeated forever.  i also noticed that pressing the primer bulb led to a couple of drops of gas coming loose.  hmmm.

i pulled the carb off and disassembled it.  it is not unlike the design shown on page one of this thread.  i also pulled the spark plug.

a couple of things to note
–– the brass float was half full of gas
–– the primer bulb rubber was cracked and leaked air or fuel depending on position.
–– there was varnish/muck in all the passageways and float bowl.
–– the spark plug was carbon'd black, from running rich (most likely as a result of pushing the primer to keep the engine running).

i played with Google for a bit, as you can imagine a 10 year old engine with 87 variants has quite a scope of parts.  nonetheless i was able to find all of the parts i thought i would need.  then it became obvious that the parts were nearing the the cost of a replacement carb.  in the end i opted to get a new Oregon 640025C carb for $36 versus spending $29 on a pile of parts to retrofit the old carb.  once received, the Oregon part was a dead ringer for the original Tecumseh, right down to the nipples used to interconnect with the fuel line and breather hoses.  

http://www.psep.biz/store/small_engine_parts.htm
http://www.psep.biz/store/tecumseh_carburetors.htm



with the new carb in place, the engine started right up.  it still hunted, but that simply requires a little adjustment.  on this and many generators, there are two adjustments.  one sets the nominal engine RPM (governor stop) and the other sets the throttle stop "preload" if you will on the governor.  the former sets the static voltage and the latter sets the compensation for dynamic loads.  

in the pictures below, the nominal engine RPM (governor stop) is set using a torx head screwdriver, below the governor assembly.  to adjust –– with no load on the engine, aim a bit high and set the voltage at around 127-130Vac.  next, using a philips screwdriver, adjust the throttle stop such that the engine does not appreciably hunt.  a little hunt with no load on the generator is all but unavoidable, so don't worry if you get a little no load variation.  

now attach a load.  i did this in two steps, first using an electric impact wrench and then using an old Hitachi 9.25" circular saw (aka a "deck saw").    the latter is a beast, and is a good test for such a generator.  

with the load applied, the generator should react quickly and maintain good RPM.  if not, adjust the throttle stop a bit to get better dynamic response.  you can't go nuts because the engine will run rich with no load if the throttle stop is set too high.  so there will be a balance point between good dynamic response with heavy applied loads, and loading up the engine with too much fuel while under no load.

hope all that helps someone.

ps:
do as a say and not as a i do –– don't work on a generator while standing on a wet surface.  i was eager to test it and it just stopped raining...  

ar-jedi

Nice job.

Excellent write up red_on_black and ar jedi.
I would of tossed that coleman gen in the metal scrap pile if it had been me ar jedi, and I'm a mechanic to a certain degree.
I hate tecumseh motors with a passion.
My hats off to both you guys for these excellent post.

This was a HUGE help for me.

Just went through a recent blackout, since I had been putting off genset maintenance, I wound up sitting in the dark. Well, not really, I just had a non functioning generator.

Wound up with a carb full of crap due to me being a dumbass and not draining the fuel before putting it away last time.

While my carb wasn't 100% identical, it was close enough to be able to use this as a guide to go through mine. Few hours of work later, I now have a happy, running generator.

Thanks for taking the time to post this.

Thanks guys!

Stay Safe,
AGreyMan

I have a tube of high strength, red Permatex threadlocker.  The tube itself is blue.  

I need to find some red electrical tape and wrap the tube.

Great reference. There is nothing worse then a generator that will not start when its cold, dark, raining, snowing, ect.

This really is a good reminder of the importance of having a spare generator. Bad gas can knock even the best Honda generators off line. Familiarize yourself with your generators, stage spare plugs/parts and a tool kit specific to the needs.

ost

Tag.  Looks very much like my garage sale generator with a Jaijang (sp...too lazy to walk out and look) motor.  It needs a carb rebuild as well.  THANKS!

Great write up Red_on_Black.  I also live in Huntsville and managed to get through the April 27 tornadoes and 5 day outage with a small 800W Harbor Freight generator, but it was clearly undersized and I now have the exact same generator you have (purchased at Tractor Supply, on sale with coupon, $270+tax out the door).  I've run this generator in for 5 hrs and am in the process of adding a fuel filter.  I'm really impressed so far.

I'd like to stockpile a carburetor rebuild kit or two.  I suspect that the carburetor is a clone of a Honda carb, and I have an few candidates, but I was wondering if you knew which carburetor kit is correct for this carb?

Thanks again for the write up.

Thanks, Dan. That storm definitely put some things in perspective, didn't it?

Out of curiosity, does your genny from TSC also have the switchable 220V output? It seems like a lot of the Champions I'm seeing lately are 110V only.

I just tried calling Buddy's Small Engine, on Triana Blvd, about carb kits but they didn't pick up. For a local small engine shop, they're fantastic. I know they stock everything under the sun for Briggs, Kawasaki, and Husqvarna, but I was hoping to find out if they have Honda kits in stock.

After I tried that, I checked eBay and was surprised by how inexpensive new clone carbs are there. There are several for $25-30 that say they fit the GX160, GX200, and clones. Amazon also has several for $20-25. Unfortunately, carb kits are harder to find (at least online). I think you'll want the GX200 kit. Hopefully Buddy's can confirm this when I get them on the phone.  

FWIW, it wouldn't be very hard to cut your own gaskets from sheets of gasket material. The biggest problem would be finding a new bowl gasket, because it is very thin with a large diameter and it's made of rubber. You could probably substitute an O-ring or seal it with RTV carefully, but that would really make a mess for future work on the carb.  


ETA: I just talked with Buddy on the phone. He carries the parts for the Honda GX160/GX200/etc., but coming from Honda they are broken up into subsets. So, he can sell you the needle or the float or any number of other parts. The gasket kit that includes the bowl gasket is Honda part number 16015-ZEO-831, Chamber set, Float, and has the metal bowl, its gasket, the screws, and fiber washers for the bowl. I forgot to ask him what his price is, but I'd expect somewhere around $25 since that bowl is included.


 

Sometimes when buying parts for the small Honda genny carbs, it might be better to just buy the whole carb and use what you need and save the rest.

Abt a year ago I bought some gaskets and O-rings and wound up with a bill that was close to half of the new carb price which was ~$115 for the whole carb and the stepper motor servo. [Honda EU2000i]

Probably less if ordered online, anyone have an on-line recommendation?

Also, H-F has a DVM on sale for ~$19 that has a frequency range that is handy to set or verify your genny speed vs output voltage.

H-F has an hour meter that works from 8 to 50 or something VDC or VAC and is only abt $10. I'm going to put one on my furnace.


The H-F meters work abt as good as Flukes, etc, for most purposes, I use both often, and I usually pick up the H-F ones first.

Thanks for the excellent instructions in this topic Red, this will help a lot of folks!

Yes, that set of storms did tend to put life in focus.

My generator has the 220V outlet and switch.  The model number of my generator is 46514 versus your 46540, but I'm at a loss to see the difference between the two aside from very minor cosmetic differences (color of on/off switch and minor verbage differences).

I'm familiar with Buddy's, in fact I was just in there last week, bought a fuel filter and some Tygon fuel line for the generator. Definitely need the fuel filter I think.  Mine ran like a Swiss watch for the first 3 hrs after initial start up, but the next day I cranked it up to get a few more hours before the first oil change and it surged badly. It had a piece of debris in the float valve. Cleaned that out and it again runs smoothly.

Given the price I may just buy a backup carb and put it away. For a rebuild kit I'd at least want all gaskets (including the bowl gasket) and a replacement needle valve and maybe a float.

So far this generator looks like a great value. The build quality on my is excellent. I'll probably put a couple of more hours on it this weekend before buttoning it up for the winter.

Thanks for the information.

"Given the price I may just buy a backup carb and put it away. For a rebuild kit I'd at least want all gaskets (including the bowl gasket) and a replacement needle valve and maybe a float."


That's a good plan!

Just for info, I've taken the carb off 5 Honda EU series now [and several of them ~4 times] and never needed to buy a part or replace a gasket.

YMMV