Lacquer Thinner to De-carbon Gas Engine

[Wborst]

Back in the 70’s I worked for a Cadillac dealer. We were told at GM training to warm the engine up. Then slowly pour a half quart of transmission fluid into the carb while running the engine about 1500 rpm’s. Then pour the last half quickly to stall the engine. Let it sit for 20 or 30 minutes. Then restart the engine. It would smoke like crazy for a while but it would remove the carbon buildup.

[nvs4602]

I would use seafoam. I used in a generator I had that would only run on full choke. I poured some seafoam in the gas tank and I was able to slowly turn off the choke and it ran fine and started right up. Also look at videos on youtube https://www.youtube.com/results?search_query=seafoam

[RedneckExpress]

Originally Posted by engine103

I'll throw one more in there, Back in the old Ford flathead days, we would slowly pour ATF down the carb. Made a lot of smoke but we were certain it did good. Jim E. OKC

Variant I know of on that is when yer about 500 miles out from your next oil change, and as long as the oil marker isn't already at max, add a quart of ATF to the engine oil and drive it for that last 500 miles, then do your oil change like normal.

[edfirebird68]

FWIW! GM used to sell a top engine cleaner. Ive done water injection, Qt of ate, and other **** in the intake .... Now I use a vac port thats as far upstream to the TB/carb as possible and rev it to increase vac then proceed to suck a can of seafoam. trying to stall but not hydro.... wait twenty min or so floor it b4 cranking . Then crank up to 20 seconds till it catches and starts to clear one it starts to fumigate cut back to high idle and let sit till clear.
Ed

[aztucwatson]

You might ask why there is a carbon problem (and how you know) because a temporary fix of any kind is, well, temporary. Next, in a world with excellent and proven additives (sea foam is one) there is not much cause for backyard experimentation unless it is just for fun.

Depending on how much is invested in your coach, safe reliable and cost effective may be a wise choice.