Generator surging fix. (I think)

[BKBoiss]

So I had this old generator I bought used about 11-12 years ago. It's just a Walmart special and this spring when I fired it up it was surging really bad. I tore the carb apart at least three times trying to clear up what I thought must be a gummed up passage, checked for air leak behind the carb etc etc. I finally gave up and put it back in the corner until I decided what I wanted to do. This is an old generator and I've fixed it a few times with parts I've scavenged here and there but it's not worth putting any money into. The other day I'm looking at this thing thinking I should just toss in back for parts when I notice the governor spring looks rather rusted and corroded. I fire it up and it's surging so bad the whole thing is jumping in the cage, I shut it off wrap a rubber band over top of the governor spring fire it up and it purrs like a kitten with a barely noticeable flutter every now and again. I gotta say i am rather pleasantly surprised.

 

[Dave M7040]

Power Fist is a Princess Auto brand. Princess Auto had their start in western Canada and is now in many provinces.
Alberta has their stores in many of its cities.
Princess Auto
The same generator is sold under other companies names in different colours.

The carbs are Chinese like the rest of the machine.

I bought a brand new carb for my machine from China for about $20. It was not exactly the same as the original carb in terms of choke linkage and choke plate but it served as a carb kit for my machine whereas through Powerfist or Champion you can only buy complete carbs.

The surging is usually because it is running lean.

Cleaning the carb includes getting the emulsion tube out which is under the main jet and using a fine wire poke out each small hole and then use carb cleaner and compressed air to finish the job.
I will provide some useful links to Champion Generators as your Power Fist product's carb is likely of the same lineage as Champion.

The first link is about changing jets for different altitudes. I am suggesting you look at it to see the emulsion tube under the main jet which requires careful cleaning to run without surging.

http://www.championpowerequipment.com/media/2052/cpetb2050018-altitude-jet-installation.pdf

The second link talks about removing and cleaning the pilot jet. I watched a you tube video on cleaning these carbs the other day and the guy who posted the video did not even know there was a pilot jet under the throttle stop screw.

http://www.championpowerequipment.com/media/2505/cpetb2050016-cleaning-the-pilot-jet-196cc-439cc.pdf

This link is for a complete carb from China just to give you an idea. Your carb may or may not have a solenoid on the bottom to cut off fuel when the switch is turned to off.

Generator Carburetor for Honda GX2 / Clone 6.5HP Engine

Dave M7040

 

[BKBoiss]

Thanks for the links. It's not a power fist, that is just a pull start I robbed from a blown engine I found in that scrap bin at a local equipment repair shop. I was going to order the new carb, the one I found was only $13 but they wanted like $68 in shipping. It's running fine for now so I'll see where it goes. I have a nice new 3500 watt I use for the camper. This old thing I use when I need to use the grinder and other such power tools away from a plug. I may try cleaning the carb again after I watch the video, everything I know how to do I've learnt from watching others and then just trying it. That's why I love this site so much.

Edit: I should have looked at the links first. I did clean that little black plastic jet, and I did try to clean that main jet but when I went to pull it out it was seized and I broke the brass shoulders where you put the flat screw driver.

 

[Dave M7040]

Thanks for the links. It's not a power fist, that is just a pull start I robbed from a blown engine I found in that scrap bin at a local equipment repair shop. I was going to order the new carb, the one I found was only $13 but they wanted like $68 in shipping. It's running fine for now so I'll see where it goes. I have a nice new 3500 watt I use for the camper. This old thing I use when I need to use the grinder and other such power tools away from a plug. I may try cleaning the carb again after I watch the video, everything I know how to do I've learnt from watching others and then just trying it. That's why I love this site so much.

Edit: I should have looked at the links first. I did clean that little black plastic jet, and I did try to clean that main jet but when I went to pull it out it was seized and I broke the brass shoulders where you put the flat screw driver.

Now I see Amazon.ca is selling some parts including carbs for very low prices and shipping. Removing the screw in main jet is frustrating. You have to have a screwdriver tip that just fits in the slot of the jet. These are usually found in the assortment of tips which come with some cheap screwdrivers. Regular screw drivers with fixed tips are either too wide to fit into the carb body or if they fit into and reach the jet they are not big enough to fill the jet slot and they strip.

If it is indeed running lean and you have masked this by using the rubber band, you will burn a hole in the piston or melt a valve. It you plug in toaster and electric kettle and it still runs smooth under a full load of 3,000 watts you should be OK.

If you find the right Chinese site in China, the shipping is far less than Canada Post would charge you. Certainly under $8 (and probably less) even though Canada Post will be the one who brings it to you on the final leg of the journey. It usually takes two weeks or less to come from China. Parts for my expensive Milwaukee tools take more time to reach me

Dave M7040

 

[PILOON]

Handy tip:
As carb cleaner is considered a hazardous product prices went wild over the years.

I discovered OVEN CLEANER, in spray cans, (like $2.00) to be an excellent substitute and it works just fine.

I do rinse thoroughly with warm water to stop any corrosive action.
It also is a great product to clean dirty greasy engines, again thorough rinsing.
I do however wipe excessive grease from zerks first (only so much it can do)

 

[Dave M7040]

Handy tip:
As carb cleaner is considered a hazardous product prices went wild over the years.

I discovered OVEN CLEANER, in spray cans, (like $2.00) to be an excellent substitute and it works just fine.

I do rinse thoroughly with warm water to stop any corrosive action.
It also is a great product to clean dirty greasy engines, again thorough rinsing.
I do however wipe excessive grease from zerks first (only so much it can do)

Piloon

To be clear we are not talking about the carb cleaner which came in a 20 litre can with a metal basket where the carb was soaked in the solution.

Not trying to be argumentative re oven cleaner but to share my experience.
I used to use it many years ago on a small Honda motorcycle I was proud of. I used it about once a year.
It sure produced a clean looking engine after I rinsed it off but over time the shiny finish on the aluminum engine sort of peeled off to be replace with a dull rougher appearance which I then could not get rid of.
To avoid this I really think a neutralizing chemical needs to be used to stop the corrosive effects of the caustic oven cleaner. Perhaps a rinse with Vinegar? I don't profess to be a chemist.
At Canadian tire stores a can of carb cleaner is less than $8. Brake clean is similarly priced. For small engine carbs a can will last for many cleanings.
Have you heard of ultrasonic cleaners for carbs. If I have a really bad one which has the main jet unremoveable because the screw slot if broken, my local small engine shop will put it in their ultrasonic machine for about $10. The degree of cleaning these machines provide is amazing.
There are a number of youtube videos on this topic. One of these days my next present to me will be an ultrasonic cleaner.

Dave M7040

 

[BKBoiss]

Now I see Amazon.ca is selling some parts including carbs for very low prices and shipping. Removing the screw in main jet is frustrating. You have to have a screwdriver tip that just fits in the slot of the jet. These are usually found in the assortment of tips which come with some cheap screwdrivers. Regular screw drivers with fixed tips are either too wide to fit into the carb body or if they fit into and reach the jet they are not big enough to fill the jet slot and they strip. If it is indeed running lean and you have masked this by using the rubber band, you will burn a hole in the piston or melt a valve. It you plug in toaster and electric kettle and it still runs smooth under a full load of 3,000 watts you should be OK. If you find the right Chinese site in China, the shipping is far less than Canada Post would charge you. Certainly under $8 (and probably less) even though Canada Post will be the one who brings it to you on the final leg of the journey. It usually takes two weeks or less to come from China. Parts for my expensive Milwaukee tools take more time to reach me Dave M7040

Yeah I ground the shoulders off of a cheap screw driver but it didn't fill the slot. I guess that is where I went wrong. It runs fine with my 1500 watt heater on high so I think it will be ok. If it is still giving me trouble I'll have to see if i can find something with cheaper shipping.