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

[Fish]

Did you take this out and visually verify that it was clear? It is the main jet.

 

[Joe Kuhn]

@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.

 

[Beamster]

My Toro/Briggs was having start and run issues. The bowl was clean but the few bucks spent on a rebuild kit with jet cleared it right up. It's a mystery to me because nothing looked amiss but I'll take the little victories without question.

 

[Scrubcadet10]

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

that's something i've never thought of.... putting a jet under a microscope to have a look see..... may order a Hubble style telescope .....

 

[Joe Kuhn]

that's something i've never thought of.... putting a jet under a microscope to have a look see..... may order a Hubble style telescope .....

Haha. We used a kid's microscope from when our kids were little. I bought one with a phone attachment so I could take pictures and post them, but haven't gotten around to it.

 

[LarryJohnson]

@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

Hey thanks for all the suggestions. I found another issue yesterday..gas in the oil.
Based on my limited knowledge and few things I've read, I think what happened was debris caused the carb float to stay up allowing gas to get in the oil. I compounded the problem by pouring gas down carb throat when trying to start. So I've flushed and changed the oil and filter. Will change again shortly after getting engine running properly.
I also found a leak in the carb, so I need to pull it again and replace bowl o-ring. I bought two new ones. I'll check main jet at that time. Honestly, I don't recall seeing where that's located on the carb.
Looking at a used John Deere this evening...been wanting a new mower..but will still work to get this running properly.

 

[Beamster]

Hey thanks for all the suggestions. I found another issue yesterday..gas in the oil.
Based on my limited knowledge and few things I've read, I think what happened was debris caused the carb float to stay up allowing gas to get in the oil. I compounded the problem by pouring gas down carb throat when trying to start. So I've flushed and changed the oil and filter. Will change again shortly after getting engine running properly.
I also found a leak in the carb, so I need to pull it again and replace bowl o-ring. I bought two new ones. I'll check main jet at that time. Honestly, I don't recall seeing where that's located on the carb.
Looking at a used John Deere this evening...been wanting a new mower..but will still work to get this running properly.

Happens all the time with old motorbikes that have a petcock that gets left on. Many naysayers claim that the float keeps the gas from flowing when off but you (and I) have found out otherwise. Unfortunately few mowers have a shutoff.

 

[Rivets]

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.

 

[mystic240]

If a jet or passage is plugged it will need a small wire or some mechanical means to unplug it.

 

[LarryJohnson]

Did you take this out and visually verify that it was clear? It is the main jet.

View attachment 57189View attachment 57190

So where's me jet. Is it under the shiney cover I'm pointing to below, or is it that shaft in the middle. The shaft has three little holes in it. Or maybe it's down inside the shaft.

Untitled by Larry Johnson, on Flickr

Untitled by Larry Johnson, on Flickr