wits end on johnson 20

[larryg]

i have a 1985 johnson 20.j20crcos while in water it basically cut back on power.cleaned carbs put carb kit in it,new plugs,wires,.did spark test on coils,which was good,did a compression check with gauge from advanced,it said 60 on both.and tested all ignition coils and power pak.noticed the coil was abt 260 instead of 275,so i gt a new one.when top plug is pulled wants to die.take bottom off does nothin,i am at a loss to whats nextor what it could be..im almost bald,from pullin hair out.lol thanks

 

[tx1961whaler]

Re: wits end on johnson 20

If it does nothing when you pull the bottom plug wire off, then there is no spark on that cylinder. You'll have to troubleshoot it. Start by swapping coils to see if the spark goes from the upper to the lower.

 

[larryg]

Re: wits end on johnson 20

have done this and it wont start,swapped the wires around to make bottom primary n it didnt start either.

 

[AlTn]

Re: wits end on johnson 20

If you're certain that you've spark to both cylinders...you may have water intrusion into that lower cylinder....does the lower plug look wetter than the top?

 

[larryg]

Re: wits end on johnson 20

no it looks abt the same as the other.and i checked it right after shutting it off.

 

[AlTn]

Re: wits end on johnson 20

Ok...your motor should start with that compression...get an air gap spark checker $10 or less at Advance..set it at 7/16" inch...pull both plugs and check for spark on each one..I use an aligator clip jumper to ground the plug not being checked...if you have a spark on each cylinder that will jump that gap...your ignition system is good to go...so that leaves fuel mixture...not enough?..too lean?..water intrusion?...do the spark check first, then move to fuel mix on that lower cylinder

 

[Cofe]

Re: wits end on johnson 20

Each coil has one of the mounting bolts as a grounding bolt. On the back side of the coils, one of the holes has a copper strip from the coil. This must be clean. and the boss where it mounts must be clean and free of paint in order to get a good ground.

 

[larryg]

Re: wits end on johnson 20

im bak.i had changed coil wires around.made bottom one (new one) main primary.it fired up.pulled plug off top one nothin happens.all the coils are clean where they attach. and there is good spark from both.hits hard too.accidently gt foot in water while testing spark on the top coil.lol

 

[Cofe]

Re: wits end on johnson 20

Those washers have to be the right type, and in the right place for a coil to work. Here is a pic.

 

[AlTn]

Re: wits end on johnson 20

Reread posts #1..#3..#8...and can't make hide nor hair out of'em...if you can establish a 7/16" air gap spark jump on each cylinder...no primary, hittin' hard, shocked me...you can leave the ignition side of this problem...anything less tends to be too subjective

 

[larryg]

Re: wits end on johnson 20

when i had the old coil on i had switched wires on coils.would not start.i then got a new coil it started as usual.switched all wires again so top ws primary,it started.switched wires so bottom was primary coil,started,but now the top coil when taken off would do nothin.. so now what???

 

[AlTn]

Re: wits end on johnson 20

Okkkkk...I think, Maybe I'm extra thick today, but I think what you are doing is ineffect the same as swapping the upper sp wire for the lower sp wire...and it's out of firing order then..it'll never start with those wires crossed. To actually swap coils, you have to remove the wire that runs to the "bad " coil from the plug that holds both wires for the coils and swap that wire and coil for the other "good" wire and coil. JUst swap their positions in the amphenol plug...if bad is in position A...and good is in position B...push the male ends out and put bad in B and good in A....if bad coil now works in it's new position...and the good coil does not work in its new position...then the coils aren't the problem.You can look to testing the voltage from the powerpack with a dva meter or adaptor then...or take a shot in the dark and just replace the powerpack. Nothing under the flywheel, baring a bad wire or connection, on a 2 cylinder cdi ignition of your year, will affect one cylinder w/o affecting the other. Now, having typed all that, you've got to establish a 7/16" dry spark gap on BOTH cylinders before you can move on...I'll post this and go look at a parts diagram for you motor..if you have something different than what I'm envisioning, I apologize..

 

[AlTn]

Re: wits end on johnson 20

well, heck Larry...yours is even simplier to swap coils on...disregard pushing pins out of plug as you can simply unplug the leads from the powerpack to the coil..so..pull the sparkplugs and using an air gap tester set at 7/16"...does either coil produce a spark that will jump this gap?

 

[jeffersondodson561]

Re: wits end on johnson 20

Have you swapped the plugs to see if the problem follows the plug?

 

[larryg]

Re: wits end on johnson 20

i have the spark tested it in a gap tester and even pulled the plug wire and held it abt an inch away and its still sparking.swapped the plugs also.bottom coil is bran new.im puzzled as to y one cylinder is dead.i had changed wires around on coil and make the new one the primary on bottom and the still good old one on top.now when i pull plug wire on top it does nothing.

 

[AlTn]

Re: wits end on johnson 20

ohhhhhhhkk...so..you know you have 1 good coil and 1 good lead from the powerpack to that coil....mark that coil good and also mark the lead from the powerpack to that coil as good...now, remove the suspect coil by unplugging it from the powerpack lead and from the block...replace it with the known good coil and plug the powerpack lead into that coil and test for spark..got a spark?..if yes...the coil that was in that spot is bad....if no...the lead from the powerpack, the powerpack itself, of a wire from either the trigger coil or the power coil under the flywheel aren't getting their signal voltage/power voltage to the powerpack....the greatest odds are that it's the powerpack...but you can test the voltages produced under the flywheel by using a dva meter or dva adaptor for a multimeter....that's how you can get a single spark condition with a known good coil or coils with a 2 cylinder motor using cdi ignition for your model year...or so it's my firmly held belief that that's how it is...if there's more, speak up...I'm kinda dizzy

 

[jeffersondodson561]

Re: wits end on johnson 20

What cylinder is the fuel pump getting it's pulses from? Pull the carb and look at the reed valves for that cylinder, a broken reed valve can stop the transfer of fuel to the intake port.

 

[twocyclemania]

Re: wits end on johnson 20

Though it's an old Firestone, I'm having similar symptoms and problems as to what you describe. I've done everything (points, condenser, coil, plugs) to one of the two cylinders. I get spark to the cylinder but it will not fire. I've been running the motor on one cylinder and the in-line ignition test light is firing like crazy indicating a good and continuous spark but the cylinder does not fire. I just did a compression check that turned out okay. The only thing I can think of (since I have spark and compression) is the reed valves. I'm about to go there next but you might want to give them a thought. I noticed someone else replied and suggested the same. Hope this helps.

 

[handirifle]

Re: wits end on johnson 20

Going back to my old AC technician days, I'd say you have a bad coil. When you switched coils to the top cylinder, it was now dead. The bottom cylinder was running the engine now, correct? If that is the case, then the coil or wire, is bad. I have seen transformers that produced primary and secondary voltages withing specs, when not under load. But place them under load, and they did not.

I realize the 7/16" gap for the tester is a type of load, but not nearly what a high compression cylinder produces. I'd suggest replacing the coils and wires (might as well do both while you're at it) and go from there. If it were a fuel delivery issue, then the coil swap would not have worked. If it were a fuel or reed valve problem with the lower cylinder, the engine would not have run or start, which allowed you to test by pulling the plug.

 

[larryg]

Re: wits end on johnson 20

thank all of you for the answers.altn was very helpful.i found one of the reeds broken,replaced them.then took it out and it died,brought it home and with the help of altn we figured it to be the powerpak also,cause of heating up and not starting,then when cooled it starts.