Engine coughs and dies at trolling speed

[davekarkoska]

I have a 1971 Johnson 25 H.P. that runs fine at high speed. At low trolling speed it coughs (misses) every 20 - 30 seconds and dies. If I keep the revs up it will stay running but still coughs.<br /><br />I have tried moving the low speed adjustment and it doesn't seem to help. Could this be electrical? Any ideas?<br /><br />1. What should the low speed adjustment be set at?<br />2. What is the point gap on that model?