1982 150 Johnson Decarb

[sruman]

Hello all. I'm interested in 'decarb' my 150 hp outboard, but I've read several products and methods. I don't think that the engine has ever had a decarb done, and compression on all 6 cylinders is around 110. I'm hoping to get a little more out of it by doing a decarb.
Does anyone have a product to recommend and a good method of "shocking" the engine? Again, I don't think it's ever been done, so a good soaking is due, if you know what I'm sayin. I would love to get a few more years out of the ole girl, before rebuilding.

 

[Sherman]

Re: 1982 150 Johnson Decarb

Seafoam or DeepCreep same product but DeepCreep is in a spray can. Follow directions on can. One simple method is to mix one can of Seafoam into 3/4 gallon of fuel and oil if you mix oil normally in a aux. fuel tank. When underway and engine warmed up switch to aux. tank run at a moderate speed for 15 min stop let soak for 15 min. run until fuel is used up in aux. tank stop and let soak for 15 min. Switch back to normal fuel. Remember to mix in oil if required.

 

[sruman]

Re: 1982 150 Johnson Decarb

I would assume that deep clean you should simple spray directly in the cylinder? I guess the directions will tell you what to do.

 

[jonesg]

Re: 1982 150 Johnson Decarb

I sprayed deep creep right into the cylinders, let it soak 30 minutes and fired it up on the hose, lots of grey water came out. Compression jumped another 10 psi. Haven't run it this yr yet but it ran strong last yr.

 

[gsyfishy]

Re: 1982 150 Johnson Decarb

Auxillary tank recommendation above is one of the best ways, but you can also purchase seafoam in a spray nowadays, remember this should be done on the water so you can run up the rpms as needed. Also when major de-carb is complete, put on new plugs, as they will foul for sure.
You can also run seafoam directly in fuel tank, this keeps carb to a minimum always.

 

[iwombat]

Re: 1982 150 Johnson Decarb

You can also use the OMC engine tuner, or sierra carbon-free. Your particular year may have a schraeder valve where you can attach the can directly. I use the seafoam 1can:1gal of premix in a 3gal tank method myself.

 

[jay mendoza]

Re: 1982 150 Johnson Decarb

And there is Valv-Tect marine motor de-carb. The most effective method is to spray any of these products directly into a hot engine, prefferably with the piston at top dead center, and the cylinder in a near vertical orientation so the solution can fill the combustion chamber and then creep past the rings. I let 'em soak at least 15 minutes, but be carefull, this stuff will do damage to aluminum if let sitting for days. Run the engine for at least 1/2 hour after treatment, bad cases may require several treatments, but always run the engine to flush this stuff out afterwards. I find that if it will start, I run it with the old plugs and change them after running for a 1/2 hour so the new ones won't get all carboned up.

 

[Sherman]

Re: 1982 150 Johnson Decarb

Warm up engine to operating temp. Then you spray deep creep directly into the carberators with the engine at idle until the engine lugs down don't let it die. Do this until you use about half a can turn off engine and let set for 15min. and repeat until the can is empty. Let set at least 15min. Run for about 20 min or untill all the smoke clears. Change plugs and your good to go. This is the process recommended on the deep creep can whichassures that the cleaner also clears the exhaust ports.

 

[jerryb43050]

Re: 1982 150 Johnson Decarb

Sorry to revive an old post, but...

I picked up a can of Johnson Engine Tune yesterday, but my '82 doesn't have the schraeder valve to attach the can to... is it okay to cut the valve off the can hose and spray directly into intakes? Would I follow the same instructions as on the can (two seconds shots each cyl., followed by 20 second shot *which cyl?*, then let soak..)...

Thanks!

You can also use the OMC engine tuner, or sierra carbon-free. Your particular year may have a schraeder valve where you can attach the can directly. I use the seafoam 1can:1gal of premix in a 3gal tank method myself.