JackC 616 #1 Posted April 23, 2015 Most will use Seafoam but Eric the car guy says just use a little water. He says the steam will break up the carbon. Has anyone tried it? Share this post Link to post Share on other sites
boovuc 1,090 #2 Posted April 23, 2015 I wouldn't do it. I know that the carbon deposits I removed from three different Onans I own required hard pressure with a Scotch-brite pad and some citrus solvent and or MEK. Pouring water into the fuel system where water itself is the enemy and creating some spontaneous steam only after it decompresses on it's way out isn't going to remove anything but very loose deposits if that. Share this post Link to post Share on other sites
DougL3 63 #3 Posted April 23, 2015 This is an often used, yet controversial procedure used on oil-head BMW opposed twin motorcycle engines known as "water torture". I personally have done it more times than I can remember and never had ANY ill affects. In fact, it always worked wonders and cured the pinging issues that were so common even with 93 octane gas. I do recommend changing the oil after this procedure! You will know why when you see it drain out. 1 Share this post Link to post Share on other sites
AMC RULES 36,941 #4 Posted April 23, 2015 Without removing the head, and doing a visual inspection both before and after... seems it's just speculation, as to whether this procedure really works, or not. 1 Share this post Link to post Share on other sites
DougL3 63 #5 Posted April 23, 2015 Without removing the head, and doing a visual inspection both before and after... seems it's just speculation, as to whether this procedure really works, or not. I can assure you it works on the BMW opposed twin...and the head gaskets for it are a "wee" bit more than $17 a piece! 1 Share this post Link to post Share on other sites
Coadster32 793 #6 Posted April 23, 2015 Interesting. I find most of his stuff to be on point. Just a little skeptical about this though. As to Craig's inspection point...should be said for any de-carboning method to see if whatever you are doing works or not. I think when things have gotten way out of hand, no "snake oil" is going to substitute a good scraping/scrubbing. 1 Share this post Link to post Share on other sites
608KEB 794 #7 Posted April 23, 2015 I asked if anyone tried using water to decarbon a few months ago when I was cleaning up my 520H. I did not try it though. I'm going to get to adjusting valves and decarboning this summer. I'll post some pics of the top of the cylinders 1 Share this post Link to post Share on other sites
decksetter 50 #8 Posted May 9, 2015 I haven't ever decarboned any of my onans. I set the valves without pulling the heads and I always run Seafoam in my gas. Maybe I'm just living dangerously. Every once in a while I do pour Seafoam down the carb while it's running. I think I'll try the water though. Share this post Link to post Share on other sites
alswagg 128 #9 Posted May 10, 2015 Most Marine shops and Marinas have products called Engine Tuner made by Johnson/Evinrude. Made specifically for removing carbon from two strokes and four stroke engines. It really does work, We stock several cans at all times. Sell for $12,50 can. Good luck Al Share this post Link to post Share on other sites
