Rough idle caused by Pulse pack?

[skyguy59]

1972 100 HP Johnson on a CV-16. I let it set (preserved) for 3 years due to various reasons. Started running it this summer. Ran perfect for a couple of outings then got a little hard to start and idled rough under 1500, ( in water or on muffs no difference). Above 1500 it was flawless. I did all the usual stuff, compression checks, cleaned carbs, changed plugs, checked wiring and connections. Nothing improved it. Finally I installed my spare pulse pack and all is right with the world. Is this possible or did I miss something. I thought Pulse packs either worked or didn't.

Any comments

Russ In Texas

 

[F_R]

Re: Rough idle caused by Pulse pack?

1972 100 HP Johnson on a CV-16. I let it set (preserved) for 3 years due to various reasons. Started running it this summer. Ran perfect for a couple of outings then got a little hard to start and idled rough under 1500, ( in water or on muffs no difference). Above 1500 it was flawless. I did all the usual stuff, compression checks, cleaned carbs, changed plugs, checked wiring and connections. Nothing improved it. Finally I installed my spare pulse pack and all is right with the world. Is this possible or did I miss something. I thought Pulse packs either worked or didn't.

Any comments

Russ In Texas

Well it generally is accepted that they either work or don't work, but those particular ones did a lot of stuff they aren't supposed to do. Like work today but not tomorrow, but ok the next day. Are you running L77JC4 plugs?

 

[skyguy59]

Re: Rough idle caused by Pulse pack?

QL77JC4 Plugs. I heard that the non resistor plugs can cause misfiring issues.I checked everything I could think of before changing pulse packs. Even looked for arcing after dark to see if that was it. Everything I looked at looked or checked good. I guess I'll just "fly it and watch it" as the saying goes!