Yamaha ring free

turbotodd said:

Years ago I worked for a John Deere dealer. I'm dating myself...bear with me.

One day a guy shows up with a RX95 rear engine rider, 12.5hp Kawasaki L-head engine. Said it was low on power, black smoke, fouls spark plugs. So I start diagnosis. Compression test. 130 PSI, acceptable. I like 150 or better but 130 is fine. Noticed that the choke wasn't opening all the way (common on those), figured that was causing low power and black smoke. Fixed the choke, engine ran better but still not 100%. Did a leakdown test and found that both valves were leaking. I figured carbon buildup based on what I'd already found. Just a week or so before, our rep mentioned Yamaha Ringfree as a decarb chemical that just gets added to the fuel. I figured I'd try it since it was either that or pull the motor.

Before dumping the stuff in I pulled the head to verify it. L-head engines are sweet-easy to work on, so I had the head off in about 10 minutes and yep-carbon everywhere, including between the valves and seats, holding them open a little-and causing low power/low compression. I bolted the head back on and dumped the whole bottle of ringfree into the tank (about 2 gal of fuel) and fired it up, then parked it outside. Within 5 minutes I could see the carbon blowing out of the exhaust. I let it run the whole tank through which took a while...like 4 hours running 3500 RPM no load. Next day I came back in and pulled the head again. 99% of the carbon was GONE. There was a perfectly shaped ring of clean metal that ran from the intake valve across the block across the piston, same thing on the bottom of the head. Seats and faces were perfectly clean other than the pitting that was already done. Called customer, explained the situation...give him the option of pulling the valves or taking the gamble to run it as is (which is what I'd have done, it wasn't that bad)..and obviously he ran it. Same head gasket & all. Guy called me about a week or so after picking it up and wanted to know what we used, told him Ring-free from Yamaha. He came in and bought a couple bottles.

I run the stuff in my cars, outboard, saws, weed eaters, lawn mowers, everything. It IS that good. My JD mower has run it since I bought the mower in 2007, at which time it had about 45 hours on it (1998 model...). I used a bore scope a couple weeks ago to have a look, and inside it looks perfectly clean. ZERO carbon buildup that I can see. The inside of intake manifolds on car/truck engines can get nasty, and this stuff will take a lot of it out, as well as clean the junk off of hte back of the intake valves which can restore some power and economy.

2 stroke engines are susceptible to carbon causing ring sticking-which is what this stuff was made for originally, to free/clean stuck rings on 2 stroke boat motors that see a lot of idling time. It works excellent on those. On a 2 stroke, the rings are responsible for dissipating a LOT of combustion heat into the cylinder walls. When the rings stick, the engine can overheat and burn pistons since the pistons can't dissipate the heat as effectively. Ringfree solves that issue.

Also this stuff works good on some of the V-twin bike engines. Like the ones that never see over 3000 RPM, the ones that the riders blip the throttle often. They tend to build carbon deposits, which sticks the valves and causes poor running. I've fixed about a dozen of them with a $17 bottle of ringfree....otherwise it'd have been well north of a thousand to pull the engine, the heads, remove all 8 valves, clean, seat, new gaskets, labor and tax.

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