Hard starting 1966 20hp Johnson

[manitoba1]

I have a 1966 20 hp Johnson which is extremely hard starting cold. Once running, the engine runs well but getting it going initially is hard. Often it'll backfire with full choke. I haven't had it long and don't know the engines history. Seems to have good spark and plenty of fuel. Any suggestions as to what I can do to get it starting properly (less than 50 pulls)?

 

[jasper60103]

Re: Hard starting 1966 20hp Johnson

Did you check your spark with a spark tester? Also, what is your compression?

edit: Aside from the checks mentioned above. I just had to get more familiar with my motor to start it cold. My motor doesn't like a lot of choke. I choke it until I get combustion, first 1-2 pulls. Then I push in the choke, and it will usually start on the very next pull.

 

[AltaMira]

Re: Hard starting 1966 20hp Johnson

I have a 1969 motor. I have found out that unless I pump the ball fully, it won't start for nothin. I pump the fuel ball up hard and she fires right up.

 

[restornator]

Re: Hard starting 1966 20hp Johnson

If it backfires with full choke, your spark timing might be off, i would twist the throttle as high as it will go in neutral. You'd think it wouldn't matter b/c the choke is engaged, but it changes the timing (at least i think).

But it sounds like the motor is starving for fuel at first. Do you have trouble keeping the bulb primed?

 

[manitoba1]

Re: Hard starting 1966 20hp Johnson

I replaced the old original primer bulb with a new one and it seemed to help somewhat. Even after priming the engine substantially it still seems to take forever to get it to fire and even then will always stall. The Johnson is for use on a small 14 ft aluminum and won't be used that often but none the less I've never seen an outboard so difficult to start and suspected maybe some type of points/timing issue. I'd be happy if I could get it to start within 5 pulls cold. Didn't check the spark with a tester but there's good blue spark across the NGK plugs. Haven't checked the compression but it's appears to have pretty good compression trying to pull the recoil. I've played with the choke and throttle settings but haven't found anything to get it to start significantly faster.

 

[bktheking]

Re: Hard starting 1966 20hp Johnson

Check compression first.

Process of elimination. Get yourself a spray bottle with appropriate mix, don't choke it, spray the mix directly into the carb, if she fires up right away you either have a carb issue or reed issue. If timing were off it would be off no matter what, it sounds like it isn't getting the gas it needs to start.

 

[tashasdaddy]

Re: Hard starting 1966 20hp Johnson

http://forums.iboats.com/showthread.php?t=299680

 

[manitoba1]

Re: Hard starting 1966 20hp Johnson

Thanks for all the helpful suggestions and that last link looks like a great one. I'll give those suggestions a try one by one till we have some success.