*THE HULL TRUTH is the world's largest FREE network for the discussion of Boating & Fishing. Whether you're researching a new boat, or are a seasoned Captain, you'll find The Hull Truth Boating & Fishing Message Forum contains a wealth of information from Boaters and Sportfishermen around the world.
Welcome to the updated THT!
If you are having trouble signing in, please email feedback@thehulltruth.com with your username and we will help you. We thank you for your patience as we help you access the new site!
Random Quote: Better to have a tragic ending than a never ending tragedy.
I have a 2000 model Johnson 150 Ocean pro. I have ran this motot two seasons without any problems. I hear alot about decarbing motors every 100 hours or season. It isn't broken so I am a little hesitant about it. But is it something I need to do? If so, how often and how. Thanks
I also have never done it and am not sure if it is necessary for a carburated engine. My 130 Johnson has plugs as clean as my car. The direct injected motors tend to build up carbon. Probably wouldn't hurt if you just add the suggested amount to your gas. I would do whatever your manual/dealer recommends - Which for my 1996 is nothing.
I had a Johnson 112 Carb motor 1996. The manual recommended OMC Enginer Tuner every 50 hours to decarbon the motor. When I did this, thick black fluid ran from the motor. I would check with an OMC dealer or simply read the manual for maintenance procedures.
I own a 1999 Johnson Ocean Pro 200hp. I was having stalling problems at low rpm's and the dealer recommended I de-carb using OMC engine tune. After the treatment the engine ran noticeably better. No more stalling and smoother top end. I'll be de-carbing from now on as part of my yearly maintenance.
Go to www.boatsetup.com and go to the "Articles" section. You find articles on how to de-carb a DFI and carbed motor.
"Everyone should believe in something. I believe I will go fishing" --- Henry David Thoreau
---------------------------------------------
º
º
<º)))«<
I do it regularly to my '99 Johnson 150. Every 50 hours is the recommended interval. This is a preventive maintenance item. Carbon build-up can cause the piston rings to stick and break leading to engine failure. Noticeable improvement each time I do it.
Warm up motor. With motor off, remove engine cover and air housing. Connect the can to the valve on the front of the engine. With engine running, open valve and spray it in per instructions and turn off engine and close valve. Let it sit overnight. Blow it out next day. Beware, very smokey the next day. I usually try to get out very early that day.
beachblitz-
I have the same motor you do. The valve that you are referring to, is it the same valve that the fogging oil can srews onto? How do you know when this valve is open or closed? sorry for the stupid questions but I'm not mechanically inclined. I do add CarbonGaurd to just about every other fill up.
actually I have that valve also and add the omc tune up as reommended at the end of the season - I guess that is "decarbonization" after all. Been doing it all these years and never knew it was decarbonizing!
Yes it is the same port you use for fogging.
You can also fog the cylinders through the plugs individually after you are done with the engine running procedures. Then turn the engine one rev by hand after disconnecting the batteries.
re: the open or closed question - pointing towards the engine is the normal running position. The manual (and the directions on the OMC cans) don't say anything about moving the lever and it does take the tune up and oil in that position - I do know from exprience that if you leave it in the other position the engine won't idle.
Really don't know the answer o that one - one poster in a previous pos on this subject said to move it 90 degrees while decarbing and fogging - then move it back
Grunt-
how do you turn the motor one rev by hand? I was never able to figure that one out.
Also, that valve only points N/S/E/W and not toward/away from the motor. Which position should it be in for fogging/decarbing?
thanks for the info
I'm going by memory here. I have a 2K 200 Ocean Runner. I think the valve only moves 90 degrees. It's either up or pointing "back" towards the motor. Just like Grunt, mine won't idle in the wrong position so it's easy to tell.
I used to have a 20' runabout with a '92 Evinrude 150. I ran the OMC Engine Tuner religeously and it would smoke like crazy after soaking overnight. Kept the mosquito's away for hours!
When I sold the rig, I had nearly 1000 hours on the engine and the compression was within 10 psi on all six cylinders. A peek into the cylinders (with a borescope through the spark plug holes) still showed the original cross hatching from honing, and absolutely no scars. Very clean, even in the exhaust ports and the piston tops. By the way, I used the cheapest 2-cycle oil I could buy (the blue ammonia smelling TW-3 stuff from Wal-Mart), and ran medium unleaded.
I used to tinker with dirt bikes, and carbon formation in the rings or ports will kill a 2 stroke motor in no time! That stuff gets pretty hard. One fleck in the wrong place and the wrong time can cause a ring to catch on a port, or cause a reed valve to stick partially open.
keyskid, thats a great site. Know of any others like it?
LI, I'm sure you do, but I just wanted to say it cause it makes me sound smart. When you fog the engine you do use the valve right? Cause just squirting the cylinders wont do anything for the bearings.
The red lever is the manual choke. As been stated, it's easy to tell which position is the "run" setting.
When fogging, use the injector adapter for the can of oil as per directions on the can. Then after that, take plugs out and spray some more into each cylinder and rotate a turn or two by hand.
this is where I keep getting confused. Where do I locate the flywheel? I did spray oil into the spark plug holes but I can't seem to locate the flywheel. As I said, I'm not mechanically inclined. I don't know what a flywheel is or looks like.
Nauti, you sound mechanically challenged as I, lol.
The flywheel is the round thing on top with the teeth all around the outer edge. The starter engages the flywheel upon starting. When the engine is running, it is turning around.
Far as I can tell, that's the only time the flywheel is mechanically used except for balancing or something. Yes, spray the fogging oil into the spark plugs holes. You'll want to have all the plugs removed prior to doing this or else you couldn't turn the flywheel without lots of effort. Ya sure as he*& don't want the motor to start while doing this either. Can't start if the plugs are out and further safety to disconnect + terminal of battery.
How to decarb a Johnson? 
