Decarbonizing 1999 Johnson 175 Carb.
 

110 hours on the 20MA. Any insight, suggestions, opinions, warnings? Just buy the Johnson brand can, and follow instructions? Sounds pretty straight forward. Never done it. Too late?

Burn cheap grade and premix. Last years remaining half tank has been Stabilized. Run every six weeks. Just recently learned of Quick Start. Guess I should have read the owners manual. Any other assistance before I fire her up. Thanks. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Vezo

First off, I have a 1999 Johnson. I use the fog every 100 hours. I burn midgrade fuel along with the OMC 2+4 fuel conditioner and Yamaha ring free every tank and burn OMC oil. I don't think it is too late to do it.

BEWARE, VERY IMPORTANT
Make sure you burn all the decarb mixture out thoroughly at idel speed before you get it on!!!! (You should not be able to smell it)

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Thanks Capt. Chuck. I just had my first service with the Yamaha 60 on the Whaler. Bought the RingFree as well. Pretty pricey stuff. $1/oz. Wow. So you are running it in a two stroke, huh? Haven't bought the Johnson stuff, but I guess it is a spray that you shoot into each cylinder after the engine has been run long enough to come up to temp.? Then spray the rest of the can into the airbox while she is idling? Is this pretty close? Only other thing I've heard is massive amounts of light/white smoke is normal? Thanks again. Mike.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Mike

There is a valve on the port side of the motor that you screw the nozzel into. Read the can as I think you give two 20 second squirts per cylinder after warm up. You squirt until the engines dies and then wait a few hours before restart. The airbox thing is news to me. The excessive smoke is normal, as mentioned above, just make sure you get it all out at low speed. I am not the expert here as my motor mech races the Johnson and was in the initial development of the 250hp 6 cylinder with OMC. He told me to use the ring free in my 2-stroke along with the 2+4 conditioner. Knock on wood, I have not had any motor failures with my last two OMC's :cool:

I think we need a expert motor mechanic to help us on this board :cool:

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Capt Chuck . . . I agree . . . maybe we can all pitch in a buck or two every month and have some Tech answer our questions!!

I've done this with Powertune and the Bombardier product. There's a write up on boat setup . . . I followed the FICHT decarb instructions (which is not with me any longer).

Here's a link to the Carb Version.
http://www.boatsetup.com/Decarb_Carb.html

But for my carb motors . . . I just followed the instructions on the can of powertune.
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On the Blown up Merc XR2 that I got for free . . . I tore it down and you wouldn't believe the carbon build up on the piston heads that eventually caused piston #5 to bite a ring and paint some pretty aluminum streaks on the cylinder wall. The carbon buildup was really thick (Looked like someone was cooking BBQ ribs on the grill). So . . . if your motor is still running . . . it's never too late.

Remember to clean off your plugs with some left over spray or replace them after you decarb.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Big Shrimpin', great point to have spare plugs close at hand. First question, which brand name is OMC? Second, I assumed you did all of this right in the yard, on trailer. Just make sure you burn it all off, right? Or do I need a day that I can dunk and run, afterwards? Thanks. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

OMC's Decarb spray product I believe is called "Engine Tuner". It's been a while. I know Merc's product is called powertune and Yamaha's is Combustion Chamber Cleaner. I don't think there's too much difference b/w them.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Thanks, Bigs. Appreciate it. Does the 99 have threaded valves near each cylinder that this hose threads onto (for 20 or so seconds)? Guess I have never looked that closely. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

No, one valve for the engine. Count the squirts x number cylinders you have :o

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Vezo-

as Chuck mentioned the valve, a schreader valve ( like the valve on your car tire) is located on the lower section of the engine towards the front of the engine part of the fuel system, ussually has a red lever on it.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

I don't know about the Johnson carbs motors . . .

On my Merc and Old Yamaha - I just shot the stuff down the throats of the carbs (while the motor was running) and followed the directions on the back of the powertune can which is a nice short version of the boat setup article.

The last time I did this . . . After the motor cooled down some during the soak period . . . I also removed the plugs and fired some spray directly onto the pistons. I turned the flywheel by hand to move the pistons back and forth to get a better shot at some of the heavier carbon spots. I don't know if that hurts (probably should talk to a professional), but the carbon seem to disolve away nicely.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Bigs, if I read that information correctly, author purchases a can for EACH cylinder. It was interesting read.

Hello Trayder. Author also states DO NOT use shreader valve. Now I'm really confused. Next move buy the OMC brand can and read. Thanks guys. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Vezo-

I was just clarifying the type of valve. I too do NOT use it when de-carbing or winteriting. I spray straight down the throats of the carbs. When winterizing I unscrew the brass plug on each carb to drain all the fuel out as well.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

I'm not a big fan of draining the carbs. They have a tendency to varnish up when empty.
I've found the best way to store a motor is: fill the fuel tank so condensation doesn't accumulate in the tank, add stabilizer to it and run it to get the stabilizer into the motor. Take your engine store shoot it in each carb (while running the motor), The pop all the plugs and shoot it in each cylinder.
Drain your lower unit to make sure there is no residual water that can freeze and crack it.
And your good to go.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Well, I used the schreader valve, as the manual, which describes Stugots, including same about Quick Start, and everything went pretty well. 2 second blasts for each cylinder, then 20 seconds continually, or until engine stalls, which was the same. Waited 3 hours and nothing came out! No smoke. No creeping, crawling crud. Nothing built up inside prop hub. Nothing. So I did it again. Now has set 12 hours. Going to fire her up now. Will report back. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Finster-


Carb's wil not get mucked up when they are drained of fuel.

Rather the opposite, when there is fuel remanaining in the carbs (that is untreated) and it evaporates what is left is gum and varnish.

You can not guarantee the stabil get mixed adequatly in your tank and gets to your carbs, I can guarantee I am able to drain all the fuel out.

FWIW I add stabill as well

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Well fired up the old two stoke anticipating a real mess. Fired up, ran to 1500 revs, and monitored while she ran for 25 to 30 minutes. Again no smoke, and almost no mess out in the yard. I guess I should be thankful. That treatment sat for 23 hours inside. Fired up idle quickly a few times to get a little white smoke but nothing unusual. Finally quit after I did not think I could smell that odor any longer. Backed her inside the garage and again inspected the plugs. Not TOO bad. Going to try running them first outing before replacing with new. Placed cardboard under prop before trimming engine (to get close to rear wall), and just water ran from engine. Doc'd everything with dig. cam., including the new hole the prop punched in the sacrificial plywood back there. I know, I know. It's tough without a backer. Both boats' trailers tongue jacks are placed on small dollies, but the Whaler just moves so much better by yourself!

Also, Capt. Chuck, I took your advice on the 2+4 additive, and yours Bigs, with the spare plugs, while I had my wallet out. I think next time I will purchase the can with straw and simply go through the carb throats. Thanks all for the help.

One more thing, while I'm stuck at work on this Friday night. News reports attacks to oil wells in Mid-East today. Nothing happened, but stock market prices almost $64./bbl.. Poor relations with Venezuela, now threatening to stop sending to US, which is 15% of our annual intake. In short, prices at the pump will rise soon. Locally, $2.14 for 87 oct.. Buy now? Is it really 90 day shelf life, or realistically, like 30 to 45?

90% rain Saturday through Sunday morning, up to one inch possible. Sun in afternoon, high 54*. Both boats ready, and bike just had 2500 mile service. Guess you guys up north really don't want to hear whining, huh? Sunday, or Monday high 11* or something. I remember those days. Have a good weekend. (There is an indoor boat show in Savannah).
Vezo, Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Just a side note - I have used Sea Foam to decarb and added the X amount recommended to a 3 gallon fuel can, mixed, and ran the fuel intake hose into the can for required minutes, let sit for recommended three hours, and blew the carbon out (and ran smoother)....

Re: Decarbonizing 1999 Johnson 175 Carb.
 

What up? Ran hard today with Part I and could not bust 4600 rpm. 1000 below standard. Ran like a top but not even close to top end. Bad/fouled plugs? Going to try new ones to see.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Did you check the compression???

Re: Decarbonizing 1999 Johnson 175 Carb.
 

What size wheel are ya spinnin'?

Re: Decarbonizing 1999 Johnson 175 Carb.
 

If you were spinning 5600 before and you're only turning 4600 now (no changes except for the decarb) then you're firing on 5 of your 6 cylinders.

Pull all the plugs and inspect the white ceramic part . . . all of them should be paperbag brown in color. One will be white. That's the one that isn't firing.

Replace that one spark plug and/or make sure the coil and plug caps are on tight. Take her for another spin.

Oh yeah . . . You probably have to gap your plugs on the OMC motor . . . so make sure that your in spec with the gaps.
http://www2s.biglobe.ne.jp/~tomo_k/img/plug_brn.jpg

See the carbon on the ends and the paperbag brown color on the tip. That's good . . . The one that comes out looking brand spanking new (from a nice petroleum high pressure clean). That's the culprit. Fiddle with the wires and the plug cap for that plug and you'll be back up at 5600.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

PeterB, I have not yet checked the compression.
Scott, OMC SS 14 1/2" X 19". Since 1999. Perfect match.
BigS, I think you are on to something. That sounds closest. Remember I used original plugs that were used during the decarb, because I didn't THINK that they were that bad. Boat ran flawlessly all day until I wanted to run WOT for a minute or so. After sitting on a sand bar for the last hour, we decided to make 5 minute run back to landing. Upon arrival, overheating alarm. Did not run over 3500 revs. to ramp, and was not overtrimmed. Like 12-15 hours on waterpump. Hope to pull plugs today. Thanks all. Part II.

Re: Decarbonizing 1999 Johnson 175 Carb.
 

Mike, just a thought. Why don't you check your linkage and control cables? Maybe your not getting full throw out of them. Check your timing aswell.