Cleaning Small Engine Carburetors

You’re a Man. Or a Woman.

You like your tools motorized. Motorized with an engine—that you have to start with a pull cord.

The kind that awesomely cut the crap out of your grass or hedges; that blow snow into your neighbors driveway; the kind that till the earth so you can plant the back forty;

The kind that can be a pain in the a** when they don’t start.

Like after they’ve been stored for the winter and you forgot to add fuel stabilizer.

Or, you did all that stuff, but you forgot to run the carb dry after shutting off the petcock—after adding the fuel stabilizer.

So the gas in the carburetor turns to lacquer.

Which, in the case of my generator, is entirely what happened.

I leave the generator tank full, holding 5 gallons, which gives me 30 gallons of gas as I have 5 cans ready-to-go-at-all-times.

Hurricanes come up quick here in Florida. I’ve been through my share, and every gas station, grocery store and convenience store is wiped clean of every gallon, box, jug, can or bag of whatever.

In 2004 we had like 4 back-to-back hurricanes that were pretty bad. Not Katrina bad, but for us it still sucked (and for some it was Katrina bad). It went like this: hurricane, no power for almost two weeks, power on, hurricane the next day, no power for 10 days, power on, hurricane two days later, no power for 6 days…

And my generator is big enough to run my fridge, a light, a fan, a griddle or microwave, a radio or tv, and charge up our other stuff (like lanterns or cell phones).

So I need the generator to work. I bust it out at the beginning of hurricane season, start it up, top it off, add the fuel stabilizer (since it, hopefully, sits for 3 months) and get all my cans filled. Then I close up the fuel petcock and run the carb dry while it sits, ready for action.

Oh, okay so the gas turns to lacquer, without stabilizer.

Just gumming up the whole damn carb.

So, again, you’re a man (or a woman) who should know stuff…like engines. You can take it apart and fix it. Or you can’t but you’ll take it apart anyway, realize you don’t know what the heck is going on, then tell your better half you gotta order a part—where you take the whole pile of parts to the small engine mechanic to fix it.

So why not try it yourself? The worst-case scenario is that you cart it to the lawnmower repair shop with your tail between your legs anyway.

Here’s what I did to clean it:

Remove the air filter housing and the carb. Keep track of the screws, nuts and bolts. A baggie works good if you have bad short-term memory. Take some pics with your phone to remember where stuff went. It helps if you’ve never done this before.

Here’s what mine looked like. See that black gummy stuff? Yeah, that use to be gas.

Here’s what mine looked like. See that black gummy stuff? Yeah, that use to be gas.

Get you some carb cleaner at the auto parts store. Start spraying stuff. Use eye protection, it can squirt right back into your eye really easily. This shows some progress after I started hosing it down with cleaner.

Get you some carb cleaner at the auto parts store. Start spraying stuff. Use eye protection, it can squirt right back into your eye really easily. This shows some progress after I started hosing it down with cleaner.

Start moving stuff around and see if it sticks. Like the throttle (choke) plate (the little brass disc in the hole in front of the venturi—where the opening narrows). Make sure you have the little tube on the end of the carb cleaner so you can jam it down into the crevices, holes, jets…spray, let it sit, spray…lather, rinse, repeat.

Since the throttle (choke) plate was really sticky, I figured there’d be plenty of gummed up crud in the float bowl, or float chamber—that’s usually the round part on the bottom of the carb.

I pulled the float bowl off. Here’s where stuff can come flying out, springs, ball valves, whatever. Chances are, your small engine carb is fairly simple—you’ll have a gasket for the bowl, a spring or two, the float…just take your time, and maybe have the equipment manual with parts diagram nearby. You saved that, right?

I pulled the float bowl off. Here’s where stuff can come flying out, springs, ball valves, whatever. Chances are, your small engine carb is fairly simple—you’ll have a gasket for the bowl, a spring or two, the float…just take your time, and maybe have the equipment manual with parts diagram nearby. You saved that, right?

I disassembled the float by pulling the pin and then just hosed everything down with cleaner. Sometimes I’ll hose it down, then cover it with a cleaner-soaked rag to let it set, and not evaporate so quickly. Then scrub it gently with a nylon-bristled brush, or a toothbrush works good.

I disassembled the float by pulling the pin and then just hosed everything down with cleaner. Sometimes I’ll hose it down, then cover it with a cleaner-soaked rag to let it set, and not evaporate so quickly. Then scrub it gently with a nylon-bristled brush, or a toothbrush works good.

The throttle (choke) plate and shaft were still sticky, so I took that apart and was able to clean the body and venturi of the carb, as well as the plate and shaft. Careful here, you don’t want to nick up the edges of the plate, shaft or lose little screws.

The throttle (choke) plate and shaft were still sticky, so I took that apart and was able to clean the body and venturi of the carb, as well as the plate and shaft. Careful here, you don’t want to nick up the edges of the plate, shaft or lose little screws.

Back to the float bowl. See all those little passageways? For fuel or vacuum to travel—they were all gummed up. I sprayed down in there with the cleaner until I started seeing the fluid run clear.

Back to the float bowl. See all those little passageways? For fuel or vacuum to travel—they were all gummed up. I sprayed down in there with the cleaner until I started seeing the fluid run clear.

If everything starts looking shiny, and the cleaning fluid runs out of all the little holes and things clear, then put ‘er back together.

I had to make some gaskets, since I did this whole thing on a whim, and didn’t get to order a kit for the carb. Here I am using the old gasket (that I ripped when removing) as a template on some gasket material. I always keep a roll of it around for this very reason. You can get it at the auto parts store. Cut the gasket out with a hobby knife—just be careful.

I had to make some gaskets, since I did this whole thing on a whim, and didn’t get to order a kit for the carb. Here I am using the old gasket (that I ripped when removing) as a template on some gasket material. I always keep a roll of it around for this very reason. You can get it at the auto parts store. Cut the gasket out with a hobby knife—just be careful.

Here’s a shot of the clean carb, and the old and new gaskets to the right. I need to clean the gasket surface. I use a razor blade held almost perpendicular to the surface to scrape away old gasket material.

Here’s a shot of the clean carb, and the old and new gaskets to the right. I need to clean the gasket surface. I use a razor blade held almost perpendicular to the surface to scrape away old gasket material.

There it is. All clean and stuff.

There it is. All clean and stuff.

Here’s the old air filter. That ain’t oil. It’s lacquer. I had a new one in the shed I’ll throw in once I put the filter housing back on.

Here’s the old air filter. That ain’t oil. It’s lacquer. I had a new one in the shed I’ll throw in once I put the filter housing back on.

 

So how did I do?

I shot this little video. Totally gambling on whether it would start the first time. It’s unedited, and my first take. Honest. I didn’t even edit out the part where I forgot to turn it to “on”.

And before you start commenting, I know, I know. I need to let it warm up a bit before sliding that choke over.

1 Comment

  • Kevin

    check the fuel filter and air filter. you can spray the carb down with some carb cleaner and see if that does anything. if not, youll need to adjust the carb

    Reply

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