Fuel mix 50:1 Why still smoking???

Johnson 15hp early 90's. I dunked the motor (repairing the rest of that today, thanks for the help guys, think I'll get it) but before I did, with a 50:1 ratio the thing smoked like crazy! I played with the air/fuel mix screw and that only affected the the way it ran, not how much it smoked. I mean a lot of smoke through the whole rpm range? Help. Thanks

Re: Fuel mix 50:1 Why still smoking???

How's the compression on this submarine?

Re: Fuel mix 50:1 Why still smoking???

Haven't checked that yet. Going to work on it today. I'm taking Sea Foam Deep Creep, carb cleaner, and some Iso Heet. My father in-law says that he changed the gas and cleaned the tank out really well, but can't be sure it was cleaned as well as I would have done it, and I cleaned the line. Will add a small amount of heet while I tear the carb(s) down and clean those with the carb cleaner. While I'm doing that, I will fill the cyls with Sea Foam, as well as the case when the carbs are removed. Assemble and then run the rest of the can of sea foam through with the fuel. Should clean it up really good. I'll check the compression after this has been done. Also will up the ratio to 75:1 for 2 gallons, then back to 50<br />Good Plan? Any suggestions?

Re: Fuel mix 50:1 Why still smoking???

What oil/gas ratio does the manual for this engine call for? Particularly after a dunking I'd be more concerned with lubrication than smoking. My 2 cents worth.

Re: Fuel mix 50:1 Why still smoking???

I am not 100% sure of this but don't 15 Johnsons "Newer ones" run @ 100/1?<br /><br />TMD

Re: Fuel mix 50:1 Why still smoking???

2,3.3,4,5,6,8,9.9,15,18 Jet,25,28 Jet, 30 hp <br />normal/severe & high performance service: <br />Using Accu-mix feature 1985-99 — <br />Not using Accu-mix feature(*) 1985-99 50:1 <br /><br />(*)Accu-mix, Accu-mix R, or oil injection disconnected or not so equipped.<br /><br /> http://www.goa-northcoastoil.com/tips/obmixing.html <br /><br />All this smoke, can it be a broken head gasket?

Re: Fuel mix 50:1 Why still smoking???

Bear are you sure about that...I am positive that I have seen some of the 90's and maybe ealier versions of 9.9 and 15's with stickers that call for 100/1.<br /><br />TMD

Re: Fuel mix 50:1 Why still smoking???

Did some checking...85-87 ran at 100:1...since then the new engines run at 50:1 <br /><br />TMD

Re: Fuel mix 50:1 Why still smoking???

Success, went through routine outlined earlier, and everything is great. I think the old man just didn't know what the outboard was about and ran the air/fuel ratio way, way to rich. My first outboard repair is a stunning success.<br />Thanks for the help guys

Re: Fuel mix 50:1 Why still smoking???

When you say the air to fuel mixture, do you mean the slow speed mixture setting? <br /><br />The high speed mixture is pre set by the main jet size and normaly can't be adjusted.<br /><br />I was under the impression if you were running at WOT your slow speed mixture won't effect your engine's performance if it is lean or rich.<br /><br />Just a thought., but glad you got it fixed.