Lacquer Thinner to De-carbon Gas Engine

[421 pilot]

Has anybody used lacquer thinner to decarbon engine

I see a lot of questions on line but not very many answers

[Zman1403]

Have heard people use it for Catalytic Converters. Not sure if it is safe to use on your engine.

[Jpony56hd]

BAD for the engine! Eats rubber most O-rings and gaskets. I know poring it down the carb misses most of these things except maybe the valve guide seals. But poring anything down the carb is dangerous, other than a flash backs, if you get too much into the engine, you can Hydro lock the engine (more liquid in the combustion chamber than the piston can compress) resulting in bent connecting rods. Keeping your engine tuned up and using a good grade of gas along with an additive once in a while to clean the fuel system is your best bet.

[DFitz]

Years ago when water (steam) injection was being tried to increase mileage I recall hearing that the steam cleaned up carbon deposits. But I wouldn't recommend pouring water down your carb, either [emoji33]

[yeloduster]

"A long time ago in a galaxy far, far away"......

I have a '70 340 Duster. Factory compression ratio was 10.5 and it DID NOT like unleaded premium. In order to keep driving it (it was my family car...I either drove it or sold it) I installed a water injection system. The water was squirted into the primary barrels of the carburetor. It had some kind of gadget that determined when to inject water.

In the winter I used the blue windshield washer fluid. A gallon of water was good for a about a tank of gas.

The water cooled the intake charge and effectively increased the octane of the fuel. It worked. Not a new idea then. WWII aircraft had water/alcohol injectors for the same reason.

As I said I HAVE a '70 340 Duster. In April we celebrated our 48th anniversary together. We are both healthy so 50 years seems like a reasonable expectation.

[All_talk]

I don't think I would try lacquer thinner for reasons already mentioned.

Running water down the carb is a thing, in the past I've done it myself. Seems to throw some black smoke out the tail pipe but I've never seen any proof that it did any real good. Water/alcohol injection is commonly used in high pressure turbocharged engines and can allow a serious boost in power.

The big name in internal engine cleaning these days is a product called Seafoam, a web search should provide plenty of reading on the subject. I have not used it myself, but many say it works. I have even seen some fairly well documented tests that seem to indicate it can be effective.

I would use caution trying to de-carbon an older engine, you could do more harm than good. If there is carbon built up on the piston ring lands you could dislodge some but not all, or a chunk of carbon could end up stuck under a ring, both situations could result in compression loss or oil consumption.

In my experience the best way to keep an engine clean is to exercise it through its full performance range regularly. I have disassembled/rebuilt many engines and the ones that are babied and never get run hard are always full of carbon and varnish. The ones that see full load and peak RPM regularly are much cleaner (and seem to last just as long).


Gary

[Waiter21]

Back in the 60's we used water... Rev the engine up, and slowly dump water in the carb..

I don't think distilled water would harm the cat conv..

[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

[followingsea]

There are products designed to remove carbon deposits and I would be surprised if there is much of cost difference.

I have only used it on my ONAN generator because it is called for in the owners manual.

[dons2346]

Would you use lacquer thinner in the engines of your 421?

[TriMoot]

Originally Posted by All_talk

........The big name in internal engine cleaning these days is a product called Seafoam, a web search should provide plenty of reading on the subject. I have not used it myself, but many say it works. I have even seen some fairly well documented tests that seem to indicate it can be effective.
....
Gary

Gary,
I believe you are right about Seafoam. I've been putting that in at the beginning of the season and since I store the gas all winter I also use a gas stabilizer. One of the side benefits of using Seafoam is when the generator motor fires up it's getting the benefits of the Seafoam and I always notice it will smoke for about 5 to 7 minutes the 1st time I use it in the spring and after that...nothing. Just seems to hum along all the rest of the year.

One other note, I stupidly got rid of my electric grass trimmer a couple years ago and bought one of the gas powered trimmers, thinking it would be easier to use as I wouldn't have to haul around an extension cord. But for some reason I could never keep the blasted thing running. I think I must have had the gas to oil ratio messed up. Any way, I stopped using it last year and for other reasons had a lawn company do my grass and trimming.

But this year I'm doing things myself and when I pulled out the gas trimmer I was determined to get it working. Well I happened to have a little bit of the SeaFoam left over and put a cap full in the small tank and gave it a pull and it started right up...smoked for a bit, and I was able to trim the entire yard none stop! And WOW! It ran like it never did before! Very responsive to the trigger and LOTS of power!

So not sure what happened, but from now on I'm putting a cap full in each time I use it!

(I am not reimbursed by SeaFoam nor were any animals hurt in this experiment)

[Washington T]

Try a quart of atf in the gas. It worked on older vehicles before synthetic oil.

[spyderRV]

Originally Posted by 421 pilot

Has anybody used lacquer thinner to decarbon engine

I see a lot of questions on line but not very many answers

Lacquer thinner runs the risk of diluting the oil coating of the cylinder and promoting premature cylinder wear. I would think that with today's computer controlled engines there is little need to worry / treat carbon deposits. BG chemicals has a concentrated techron chemical called 44K, great stuff.

https://www.youtube.com/watch?v=S2yNvI2h6Vo

[Finance]

^^^ This is the vintage forum, you know.

A little water drizzled down the carb throat at a high idle is good for removing carbon. Learned that from some old school mechs back in the day. Done it myself many times on older vehicles.