No Power

[mmckelvey]

I have an 18hp 1957 Johnson and it has no power, my 5.5hp pushes the boat faster.<br /><br /> Any suggestions

 

[flech01]

Re: No Power

There are so many things that can cause this problem. I will try to list things you can check.<br /><br />Fuel- Tank, lines, bulb, mixture, fuel filter,<br /><br />Carbs- How long has it been sence they have been cleaned or rebuilt. Try cleaning first mabe just spray some cleaner in them befor takeing apart.<br /><br />Prop- The pitch is a key factor in performance.<br /><br />What do you think it is? Does it run good, does it idle, how hard is it to get started?<br /><br />If you reply with a little more info on what the motor is doing ior for that matter what it is not doing. Start small then work into bigger problems.

 

[mmckelvey]

Re: No Power

Ok the fule tank is good, lines from tank to engine are new, fuel/oil mix is 40-1, gonna rebuild carb tommorrow, but I just nottices a little split in the air hose that goes from the coupler to the carb will replace that. Ok I had the engine starting on the first pull then she died and I couldn't get her started for a few days, maybe I flooded when I pulled the choke to kill the engine. (I'm a newb)<br /><br />Thanks

 

[flech01]

Re: No Power

You should have a kill switch on that motor.<br /><br />The best thing to do is get a manuel this will help you alot.

 

[mmckelvey]

Re: No Power

that year motor did not come with a kill switch and I have yet to rig one up.

 

[petrolhead]

Re: No Power

A '57 should be running on 25:1 gas & oil.

 

[flech01]

Re: No Power

What should it run with?

 

[mmckelvey]

Re: No Power

not an 18hp it is supposed to run on 40-1 according to Johnson

 

[Paul Moir]

Re: No Power

The '57 has plain wrist pin bearings on it's connecting rod, and I belive also on some of it's crankshaft journals. I would use the recommended 24:1 (25:1). This is the original mix recommended by OMC.<br />alien_boogie - There's some interest in a memo once put out by OMC where they changed their earlier engine mix recomendations to 50:1. Specifically, out of interest, who told you 40:1?<br /> Memo alcan found.<br />Iboats oil mix Conventional Wisdom <br /> OMC Oil mix discussion <br /><br />Use 87 octane gas and TC-W3 rated outboard oil.<br /><br />Does the throttle plate up under the engine turn with the throttle control? If not, try grounding out each plug wire in turn, and running the engine to determine which cylinder is not producing power. Spray fuel-oil mix out of a windex bottle down the carb's throat while your running and see if the engine picks up. If not, your running lean and have a fuel problem.

 

[mmckelvey]

Re: No Power

PRE-1964 JOHNSON/EVINRUDE/GALE - 18hp and up can run at 40:1, as they are mostly jeweled motors. Anything smaller run it at 24:1. Pre 1950 - any size, run it 24:1. If it's used for racing or high performance, double up the oil...<br /><br />I got this from Chinewalker' Topic C. Fuel/Oil mix- Most Motors Covered Here...

 

[Paul Moir]

Re: No Power

Ha ha! - I over looked that one. What a dummy, eh? <br />Bear in mind, he does mean 'can run', not 'has to run'. If you wish, you can run 24:1.

 

[mmckelvey]

Re: No Power

I'll try that

 

[petrolhead]

Re: No Power

So is it OK to run my '58 18hp Johnson with less than 24:1, if I'm running it at low throttle as I have to on my local stretch of river?<br />And would it be worth sourcing a finer pitch prop than currently fitted to allow it to rev higher at low speeds?

 

[mmckelvey]

Re: No Power

I had it out this weekend before I rebuilt the carb and it started great the engine was going good (still no power) but every once in a while it would try to pick up but then slow down again, checked the engine found a crack in the air intake hose...fixed that but I noticed some fuel in the bottom of the engine hood what could this be. (still haven't tried the 25-1 mix)

 

[flech01]

Re: No Power

Thats sounds like a carb problem try a rebuild or at the least open them up and see what is going on inside them.