Won't Run on New Gas - Will Run on Carb Cleaner

[slomo]

The carb was taken apart and sprayed with carb cleaner, all holes in carb sprayed with same.

UPDATE - "The carb was taken apart and sprayed with carb cleaner, all holes in carb sprayed with same."

 

[slomo]

@LarryJohnson - I once had a surging problem that was solved by running jet cleaners through the holes in the nut at the bottom of the bowl. Spray and/or air isn't enough sometimes.

See my avatar picture to the left. Jet cleaners are twisted wires of different sizes and often come with new carbs or you can buy them on line easily. My son actually put a jet under a microscope and showed me the fuzz that was around the hole. After the jet cleaners were run through the hole, it was clean and the surging stopped.

This is often my first repair effort if the gas is old, there is surging, or it won't run at all. Of course the bowl can be cleaned as well. I will leave the carb on the machine, take the bowl off, clean the bowl, clean the jets as shown to the left and even the passageway above the nut - with the carb still on the machine. Be careful not to have the float and attached parts fall away.

Good luck and if you need a set of jet cleaners, send me your address in a personal message and I'll mail you some.
View attachment 57195

These are the worst thing you can use to unclog a soft brass jet. They are abrasive and will enlarge the brass orifice size.

What I use is fishing line. Monofilament fishing line is made out of nylon. Nylon is softer than brass. Use like 2-4lb test for pilot jets. 10-30lb line for main jets. Simply toss in the trash when done. It bends easy if need be while cleaning too.

slomo

 

[Joe Kuhn]

Those “jet cleaners” are actually acetylene torch tip cleaners, which are files and from my experience wouldn’t recommend using on a carb fuel jet. They will enlarge the jet size. Just my opinion.

Good clarification!

Carb jet cleaners are spun wire:



Torch tip cleaners are files:

 

[Joe Kuhn]

These are the worst thing you can use to unclog a soft brass jet. They are abrasive and will enlarge the brass orifice size.

What I use is fishing line. Monofilament fishing line is made out of nylon. Nylon is softer than brass. Use like 2-4lb test for pilot jets. 10-30lb line for main jets. Simply toss in the trash when done. It bends easy if need be while cleaning too.

slomo

I've not had any problems with the spun wire cleaners. They're pretty soft so you can't apply a lot of pressure with them. I am careful...Your point is well taken. We're removing debris, not expanding the inside diameter.

 

[Ronni]

Can't figure out why mower won't run on gas, but will run on steady stream of carb cleaner. I've been using the old mower for 5 years with no issues. After a number of uses this year, it just stalled out. I assumed the gas was bad, so I emptied the tank, lines, and carb bowl. The only way it will run is with a steady stream of carb cleaner. I visually confirmed the fuel pump is pumping. Don't know what to do next..

Your jets might be clogged in the carburetor. Gasoline can sulfate if it gets old and will clog your carburetor jets. If you can't clean those jets, you may have to buy a new carburetor. You can prevent this from happening in the future by using something like STA-BIL 360 Protection Ethanol Treatment And Fuel Stabilizer.

 

[LarryJohnson]

Your jets might be clogged in the carburetor. Gasoline can sulfate if it gets old and will clog your carburetor jets. If you can't clean those jets, you may have to buy a new carburetor. You can prevent this from happening in the future by using something like STA-BIL 360 Protection Ethanol Treatment And Fuel Stabilizer.

Couldn't find the jet. See post 30.
Had trouble with the bizarre main o-ring as well. Decided to buy a new carb, just $20 for new complete unit on eBay.

 

[Joe Kuhn]

Isn't your main jet being pointed to here with a punch?


I'm after clarification. Not saying you shouldn't have bought new.

 

[Don Lanier]

Spraying Carb Cleaner thru a running engine doesn't CLEAN the carburetor, you need to remove the carb, disassemble, and spray and soak the parts to thoroughly clean it, Hydro Tank would be best, using Welding tip cleaners to pass through all the orifices, jets, Main Jet, Remove the Float, Needle Valve, and clean the tips and passages, spraying carb cleaner through a running engine may remove some carbon from the combustion chamber, but does nothing to the Carb itself. We have seen this issue repeatedly this year and its worse every day, whatever is coming out of the refinery's with the ethanol is barely good for Power Equipment, We always recommend 89 octane as it has a better detergent package, but the ethanol will deteriorate and ruin parts over time.

 

[matt man]

On carb jets did you poke with say a tip cleaner or like a guitar string

 

[SARG]

Couldn't find the jet. See post 30.
Had trouble with the bizarre main o-ring as well. Decided to buy a new carb, just $20 for new complete unit on eBay.

After 50 years of dicking with small engines that are not running right and the issue seems to be fuel related ............. I buy a new carb ............ fussing around trying to remedy carb problems is a true source of frustration