decarbing motor

redcajun18

Cadet
Joined
Dec 5, 2006
Messages
12
ok i have a 1988 johnson gt150 that i am tryin to decarb. using seafoam in the prescribed manor. one can in a gallon of premix and shooting deep creep into the cyls also. the question is this, i have done this three times and i am still getting lotsa smoke and black gunk outta the exhaust. when i say i have done it three times i mean three gallons of fuel and three cans of seafoam. is the motor really this carboned up?
i must admit the thing has never ran better or sounded smoother but i don't want to hurt it either. should i just keep goin or whaat? also my idle speed went from around 600 up to 1000 rpms, i think thats beacuse its running alot more efficiently now than it was before. when i put in a new impellor i did notice alot of carbon in the exhaust tract but i would have never thought it would last this long! that seafoam is some good stuff!
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: decarbing motor

adjust your idle down to around 650 again, shifting at 1000 can damage the lower unit. keep up the seafoam. it's got 20 years of crap in it. seafoam is not going to hurt it.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: decarbing motor

I have looked all over for Seafoam here in Ottawa, Canada and have not found it. Does anyone know where it can be found nearby? thx...
 

JC1933

Chief Petty Officer
Joined
Dec 31, 2003
Messages
443
Re: decarbing motor

Hi Samo

Do you have a bumper to bumper automotive store in your area?

This is where I purchase my supply of sea foam & deep creep.
If they don't have it on hand they can order it for you.

Good luck...d:)
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: decarbing motor

Don't be trying to fix something that's normal. Smoke is normal from the oil you put in the fuel. Black stuff in the exhaust is normal and harmless. Carbon build-up in the combustion chambers, pistons and ring grooves is what you are trying to clean out, and it sounds like you've accomplished that.
 

h_lankford

Petty Officer 2nd Class
Joined
Aug 6, 2005
Messages
135
Re: decarbing motor

F_R, I think what you said (and I agree) is that all the gunk he is seeing now is not from the rings (where it is most important and only a small amount). Instead he is now just cleaning out the normally dirty exhaust passages
 

redcajun18

Cadet
Joined
Dec 5, 2006
Messages
12
Re: decarbing motor

ok i know 2 strokes are goin to smoke a bit but i get clouds out of it. i am carefully mixing the oil in the gas so as to not get too much. but when i start the thing(without the seafoam) it makes a huge cloud of smoke. normal? i'll try it this weekend and see if she runs better. i am going to keep putting seafoam in the tank to keep up the cleaning even out on the lake

thanks for the replies folks
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: decarbing motor

Want to cut down on the smoke and embarrasment? Use Castrol Full Synthetic TCW-3 outboard oil. Smokes less, doesn't create as much sheen on the water, and is bio-degradable. And costs more. But I have switched. Got tired of all the stares at the launching ramp, plus it feels better to be more responsible to the environment.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: decarbing motor

F_R is right on. Your increase in idle RPM is a good sign. Likely that you have the engine combusion chambers clean at this point. It is normal to smoke at lot with continued use of the decarb solutions. Your continued cleaning is probably dissoving the soot deposits in the exhaust chest and down the midsection-not something that you generally do not have to worry about..
 

schmir

Cadet
Joined
Jan 2, 2007
Messages
7
Re: decarbing motor

I switched to the Pennzoil synthetic blend oil and am very happy. Almost no smoke at all. It believe it was $11 or $12 for a gallon at walmart. I thought that was pretty reasonable.
 
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