Decarbonizing 1999 Johnson 175 Carb.

[Bigshrimpin]

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.

[Michael Vezzosi]

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.

[Trayder]

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.

[Finster]

unscrew the brass plug on each carb to drain all the fuel out as well.

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.

[Michael Vezzosi]

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.

[Trayder]

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

[Michael Vezzosi]

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.

[John R]

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)....

[Michael Vezzosi]

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.

[peterb]

Did you check the compression???