18 hp evinrude Idle issues

[2fast4u_evinrude]

I have a 71 evinrude 18hp Fastwin and finding that it does not idle very well. I can get it to idle for about 10-30 seconds and it shuts off. Does also smoke alot. I did get new plugs and the carbed cleaned out, fuel filter. My neighbour looked at it and he thinks that there is too much oil in the gas as the gas is more of a blue color. It does start on first pull so starting is not a issue. I can rev it up and does stay running. U think the oil/fuel mix could be the problem? I didnt mix it. When I bought the boat a 2 weeks ago it had gas in it.

 

[Daviet]

Re: 18 hp evinrude Idle issues

Should use a 50:1 fuel/oil mix.
Check compression, spark and fuel delivery, it almost sounds like you are running on 1 cylinder.
Low speed jet should start at about 1 1/2 turns out.

 

[2fast4u_evinrude]

Re: 18 hp evinrude Idle issues

Should use a 50:1 fuel/oil mix.
Check compression, spark and fuel delivery, it almost sounds like you are running on 1 cylinder.
Low speed jet should start at about 1 1/2 turns out.

Really? even if the motor stays running at higher RPMs? It just idles like crap but with in gear and moving on water she moves good

 

[Bob_VT]

Re: 18 hp evinrude Idle issues

Check for spark in both cylinder's. That 18 will run on a single cylinder and sound fine but will have no power.

Since it is new to you..... and you have done this much work .....I would pull the flywheel and check, clean and maybe replace the points. We are talking about a motor close to 40 yo and it will make a difference.

 

[2fast4u_evinrude]

Re: 18 hp evinrude Idle issues

Check for spark in both cylinder's. That 18 will run on a single cylinder and sound fine but will have no power.

Since it is new to you..... and you have done this much work .....I would pull the flywheel and check, clean and maybe replace the points. We are talking about a motor close to 40 yo and it will make a difference.

Ok I will check it out. Since I am new to this How do I check for spark? Pull the re-coil and have the plug wire hanging loose off the plugs?

 

[Bob_VT]

Re: 18 hp evinrude Idle issues

If you have access to a old timing light with an inductive pick up that make very short work of it

 

[bob1340]

Re: 18 hp evinrude Idle issues

My son has a '71 18 hp model as well that acted the same. I had installed a new fuel pump, cleaned the carb, new points coils and condensers, resurfaced the head and she still idled bad. It ran real smooth at higher rpms in the tank. I put it in the lake and although it ran smooth it had no power and idled poorly. Sure enough the bottom plug was not firing. When I worked on the ignition I had a wire rub after I put the flywheel back on and it shorted the condenser out. New condenser and she runs like a stripe butted monkey.

Pull the plugs. Doing one at a time hook up the spark plug cable to the plug and lay it on top of the moter so the hex portion of the plug is grounded. Pull the rope and look for spark.