Interesting. I noticed my engine overheating on the hose last two times I ran it on the hose. And by coincidence, those were a spray into the carb. decarbing session last summer (which I aborted because of the overheat alarm) and then when I fogged it in the fall (same method). I don't know if it's just because of the defogging and decarbing or if it is always like that since I very rarely run it on the hose. Maybe spraying into the carb causes stress and more heat. I do know my mechanic told me he thinks the big engines don't do as well on the hose because the hose might not supply enough water for the pump to pressurize and adequately supply the cooling system.Originally posted by Sivart:<br /> Never have heard of it before this forum. I purchesed the supplies and plan on decarbing this weekend. My only concern is overheating during the decarb process. We decarbed my dads 150hp Yammy last weekend and it overheated. Never has on the muffs before. We took it to the lake to run on the water. It was just fine on the water.<br />I am a little worried about having an overheating problem on my XP 200. Is there something that happens during the decarb process that causes the engine to run hotter?
I boated 25+ yrs and 1000s of hrs without decarbing. Then started decarbing regiously in the mid 80s. The reason I got "religious" was a burn't piston from crud build up on the piston crown at 1000+ hrs. The crud retained heat and melted a hole through the crown...compression dropped to about 40 psi. <br /><br />The motor (OMC 140) was run the last 700 hrs without tstate and "cruised" easy. The crud didn't get blown off and the cold running made it worse. Only one piston had major crud and the ring lands were relatively clean on the other three pistons. TCW oil always used on this engine, mostly OMC brand. <br /><br />After that experience I bought OMC Tuner by the case and decarb every season or so...200-400 hrs. One can per carb and let it sit 30-60 mins after the fog. Then to the next carb.Originally posted by rickdb1boat:<br /> Just curious, how many of you decarbed your motor before you started reading all the post about it on here? I recently started doing it because of the advice on this forum, but for me and others I dealt with, it really was not the norm a few years years back. Never heard anybody mention they decarbed there motor. I never decarbed for MANY years and never had a problem. But then again, the motors that I had ran very well and they ran clean enough(From cylinder and piston inspection) that there did not appear to be any problems with carbon build-up. I know it's been around a long time now, as I remember JB posting about a few drops of water in the carbs would burn of the deposits. Just curious...
