Johnson & Evinrude fuel/oil mix

mmacro

Recruit
Joined
Jun 22, 2010
Messages
5
I am getting a Fling that has a 115 hp OMC (Johnson & Evinrude) engine to run the jet drive.

I think the fuel pump that also mixes the oil is not working properly. The engine runs fine at idle, but when put under load it right away starts to overheat.

The fastest way I know to confirm this is to mix a tank of fuel/oil and pinch off the oil line.

If the engine runs fine then we have the problem. If not it has to be something else.

What is the recommended fuel/oil ratio I should use? I have seen 30:1 and 50:1 mentioned in the forums here.

I suppose to start with the 30:1 and if it puts out too much smoke/runs poorly then back off to 40:1 or 50:1.
 

mmacro

Recruit
Joined
Jun 22, 2010
Messages
5
Re: Johnson & Evinrude fuel/oil mix

Uhmmm... I did post the hp and the engine type. And the setup in a Fling is pretty unique, people with experience with them know right away what another is talking about.

But thank you for the advice on the fuel/oil mix. I don't have the boat in my possession yet. I just know that once I do it will drive me crazy to get it in the water.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Johnson & Evinrude fuel/oil mix

If you are going to run the TurboJet engine at high performance levels, use the 24:1 ratio with synthetic oil; the engine will last longer. 50:1 is fine for normal cruising. The Fling did not come with a tachometer, but it's good to have one.

The overheat is usually from one of two sources: the thermostat housing is blocked because the sand filter has not been maintained, or because the water passage deflectors have moved out of position.

BTW, The Fling 115 Turbojet engine is usually a standard 115 crossflow with a few modifications for inboard use. To do much maintenance on the system, the factory service manual is a necessity. http://www.outboardbooks.com/index.cfm?fuseaction=search.main
 
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