Old school carb trick to get you home in emergency

[Mountianjustice]

I've got a 92 C1500 v6 5speed. But that's not the subject here. I was helping a retired friend today. We were working on an old carbed truck. His close 75 yrs old. Anyway we got it running enough to say it was running. But it was clear the carbon was dirty. Truck has been setting close 3 yrs. So its running but not well and he tells me get in it so i do. He then tells me to rev it a few times then hold it to the floor. This is while running I'm thinking ok so you wanna blow it up I guess. I do what he says rev it about 3 times to around 3-4000 rpm then stomp it to the floor and it starts climbing in rpm and at about 4000 or so he stuffs an old rag in the carb and seals it up. Till the truck shuts off. Then tells me to restart it. I do and it runs like a different truck. He told me that's how they did it when he was young. Revving the ending gets a good vacuum going then you plug it the engine tries to breathe through every port and passage in the carb and pulls the dirt through the jets and passages. In convinced on this little trick and thought I'd share it .

 

[df2x4]

It's a good one! Not sure where I first saw that, one of the Motor Trend shows I think. Probably not something I'd count on regularly, but in a jam it just might get you home!

 

[skylark]

The other trick to that is to pour some automatic transmission fluid or water in the carb in small amounts. The fluid is cool and breaks up the carbon with a thermal shock and will clean up the combustion chambers. Water actually works better because it turns into steam and that really does it quickly. If I use atf, I typically will get it as best as I can and then do it one last time quite heavy and let it sit overnight.

 

[phat69]

Swapping a couple of plug wires worked good on carb'd 4 bangers. The backfire would clean all the jets real nice.