Possible to decarb in tank?

[halas]

I just bought a boat and motor.
1979 Johnson 85 Hp.
Compression 138,135; 128, 93.
I should do the decarbonating with the Seafoam to see possible improvement.

The boat docks are not in yet for the season but I wanted to decarb soon.
Can I just do it on the driveway? Is it necessary to run the motor wide open at the end of the treatment to blow it all out?

 

[tx1961whaler]

Re: Possible to decarb in tank?

You can do it in the driveway, BUT, if you have neighbors they will hate you and the fire dept may come. It smokes that much.........

 

[Tinman57]

Re: Possible to decarb in tank?

I've decarbed my 88 hp in a barrel in the driveway. The smoke coming out of the barrel wasn't too bad, and I used a garden hose to knock some of the smoke down.

Don't try it on earmuffs in the driveway. I did that once with a 25 hp 'rude, and the smoke was incredible.

 

[tashasdaddy]

Re: Possible to decarb in tank?

also on muffs, if it is really dirty, the goo out the exhaust, will make a real mess.

 

[kenmyfam]

Re: Possible to decarb in tank?

Personally I would wait to do it on the water.

 

[halas]

Re: Possible to decarb in tank?

I guess I could try a partial treatment:

-run motor to warm up
-remove spark plugs and spray into holes and let it sit for 15 minutes
-reinstall plugs and run engine with more seafoam sprayed down into carbs
-run motor for few minutes on high idle to clear out stuff

This would allow me to slow down if the smoke is blowing the wrong way.

Recheck compression.

This would be a partial of the original tashasdeddys's instructions.

 

[tashasdaddy]

Re: Possible to decarb in tank?

Yes, just let it run at high idle, do not stop if it is smoking, the heat is what helps clean thing out.