Calling All Johnson People for Help!!

[Billy Bob]

Hey There<br /><br />Got a 1968 40 hp Johnson. It is a 2 cylinder motor. It runs rough. Did the remove a spark plug wire to check which is the offending cylinder. When this was done, the motor actually ran better. Any ideas???<br /><br />thanks<br />Billy Bob

 

[daveswaves]

Re: Calling All Johnson People for Help!!

So now you have a 20 hp johnson with a built in compressor! Check the compression on both cyl, it sounds like one cyl might be really low.

 

[ShafferNY]

Re: Calling All Johnson People for Help!!

So now you have a 20 hp johnson with a built in compressor!

Good one!

 

[Billy Bob]

Re: Calling All Johnson People for Help!!

yes, wow, that was a good one.<br /><br />Here's the deal. My 20 horse Johnson has 120 compression and my built-in compressor has 120 compression. Any other ideas???<br /><br />Billy Bob

 

[JB]

Re: Calling All Johnson People for Help!!

Howdy, BB.<br /><br />Do you have spark to the dead cylinder?<br /><br />What happens if you squirt a bit of fuel into the offending carb?<br /><br />Let us know.

 

[Billy Bob]

Re: Calling All Johnson People for Help!!

JB<br /><br />Don't know about spark. I would have thought so since it apparently is firing or misfiring.<br /><br />I did not mention the carb as much as I can tell it only has one?<br /><br />thanks<br />Billy Bob

 

[JB]

Re: Calling All Johnson People for Help!!

Misread year of your engine.<br /><br />Check the spark.<br /><br />Define "runs better".<br /><br />Let us know

 

[Billy Bob]

Re: Calling All Johnson People for Help!!

JB<br /><br />I thought it would be enough to say "ran better" Guess not. Anyway, it had rough idle, wanted to rev, coughed every few seconds this with two wires in place. When top wire was removed, motor had smooth idle, no coughing. It was 100% of what I'd like for both cylinders to be doing. Did not try to increase rpm's though so don't know how it would have behaved.<br /><br />If you need more questions answered, do so. But man, I sure wish someone could tell me what the ____ is going on. Or at least a good guess.<br /><br />thanks<br />Billy Bob

 

[BKool68]

Re: Calling All Johnson People for Help!!

It sounds like something in the top cylinder's ignition is causing a misfire. Try swapping parts between the cylinders to see if the miss moves. It could be the plug, wire, coil, trigger...<br />Good luck. Brian

 

[hondon]

Re: Calling All Johnson People for Help!!

Try a new set of points.I'll bet the ones you have in there are worn and thusly gapped too wide causing preignition.At any rate thats just good hygene if you don't know when they were last changed.

 

[Billy Bob]

Re: Calling All Johnson People for Help!!

Hey Guys<br /><br />Thanks alot. Will try those suggestions ASAP.<br /><br />thanks again<br />Billy Bob

 

[fireman 757]

Re: Calling All Johnson People for Help!!

I'm betting on a bad ignition coil. Swap the coils and see if the other cylinder misfires. It is probably cracked and arcing.

 

[Johnsonzzzz1]

Re: Calling All Johnson People for Help!!

Yup. I also say bad ignition coil.

 

[Billy Bob]

Re: Calling All Johnson People for Help!!

Thanks Guys<br /><br />Looking forward to running all 40 ponies at one time. <br /><br />Billy Bob