Decarbonizing

[brmoore]

I have read a lot of the posts on here and a lot of people talk about decarbonizing your outboard. I was wondering how this was done, how often it should be done, why it should be done, and what products are needed to do it. I have an 89 Force 125. Also, will this help compression? Thanks

 

[dhammann]

Re: Decarbonizing

This used to be called "de-coking" in the old days. There are additives that can put in the fuel mixture or directly into the air intake, however, be skeptical about any "mechanic in bottle". The proper way is to disassemble the engine, the real threat is stuck rings which can scuff cylinder walls. If your engine is running fine why worry? The way you use your engine is more important. If you idle or run at trolling speeds this can cause engines to carbon up. Also engines that are adjusted too rich will cause same problem. If you don't run WOT more than 20% of the time, lighten up your fuel/oil mix...the factory recommendation is based on running at WOT 80% of the time. Remember 2 cycle engines are designed around this problem, the rings are able to take a fair amount of gunk before siezing. To answer your question about increasing compression, it can if it builds up on top of piston but it can also reduce compression if rings get stuck. My advice, do a compression test and compare with specs and more important they should be a few lbs +/- of each other. If this is just a pleasure craft and running OK, do yourself a favor and just enjoy.

 

[Bry21317]

Re: Decarbonizing

I had read and done the same thing that you are doing. I took the advice of one of the experts from on here and used the Deep Creep spray made by Sea Foam. http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=17;t=003909 <br /><br />I was able to get this from Napa for about $5 and it worked great on my 88 Force 125 HP engine. It made alot more of a difference than I thought it would. It now runs great. The compression came up on all cylinders from 146PSI to about 149. I can tell when more on the lake. I was running about 32MPH before the Decarb, after doing the decarb I was up to about 36 mph, so it at least made a difference. <br /><br />The instructions are on the can, but basically all you do is run the engine at about 1500 RPM, by holding the throttle on the engine. While spraying the whole can of Decarb into the carbs. It will smoke, extremely. My Force Smoked up the neighborhood and made it look like everything was on fire. Once you get the to almost the bottom of the can, let off on the throttle and the engine is supposed to choke out due to the Decarb spray (My Force won't die no matter what I spray in it though, so I just turned it off). Then let the engine sit about 15-20 minutes. Crank it back up and watch everything come out of the Exhaust shute above the prop. I ran mine about 30 mins once i had started it back up, but was on the water muffs. I couldn't get to the lake when I did it. It will smoke pretty good and clean everything out. They recommend replacing the plugs after doing this, but I had just put new ones in, so I pulled them and cleaned them.<br /><br />I am about to take it back out to the lake tonight, depending on weather and see what it will do now.<br /><br />I have just rebuilt the carbs, added Boyesen Power Reeds, which are supposed to give more power, and retimed the engine. It is purring and revving like it never has before now, at least on the water muffs so I cant wait to see what it will do. You can read about the Boyesen reeds at: http://www.boyesen.com/products/outboard/index.html <br /> <br />FASTER STARTS! No more sitting and cranking while the other guys are heading for your honey hole. With Boyesen Power Reeds, your outboard performs great from the instant you turn the key! <br /><br />SMOOTHER IDLE! No more coughing, sputtering and dying. Boyesen Power Reeds smooth out the rough spots and cure coughing outboards! <br /><br />FASTER HOLE SHOT! When you bury the throttle at blastoff time, your Boyesen-equipped outboard will leap into action and put you out front of the pack! <br /><br />BLAZING ACCELERATION! Boyesen Power Reeds increase your outboard's acceleration so dramatically that they're banned on the B.A.S.S. Tournament Trail! (Registered trademark of Bass Anglers Sportsman Society of America, Inc. <br /><br />SMOOTHER TROLLING! An outboard equipped with Boyesen Power Reeds will troll down to a heartbeat, allowing more precise bait or lure presentation! <br /><br />INCREASED FUEL ECONOMY! Because they're far more efficient than ordinary reeds, Boyesen Power Reeds can make your outboard up to 10% more fuel efficient! <br /><br />INCREASED RPM AND TOP-END! Boyesen Power Reeds deliver a 100 to 300 rpm boost to your outboard, together with top-end performance designed to put you on the winning track! <br /><br />Hope this helps,<br />Bryan Cox

 

[brmoore]

Re: Decarbonizing

Thanks for all the great info. I will check it out. I do have low compression in my #2 cylinder, maybe this will give it a boost! Good luck on the water.