1980 GS850GL kinda rebuilding one bolt at a time.

[RichDesmond]

Has anyone every had a sparkplug break/quit working in mid ride? Swapped out the #1 plug with a cleaned used one I had around and everything is great. Finally getting about 42mpg on my ride today.. First time it's been that good in 8 years. Thanks for everyone's help on this.

If it happens again on that cylinder, replace the spark plug cap (assuming you haven't done that recently). I've never had a plug fail, but caps have crapped out on me a couple of times.

[Uncamitzi]

New caps last year.. saved the old ones and tested their continuity and resistance and they are all fine.. It's probably more of a valve problem. Compression is near the lowest passable on 1 and 4 cyls and valve seats probably need to be addressed on a 40 year old engine... so there's that too.

If it happens again on that cylinder, replace the spark plug cap (assuming you haven't done that recently). I've never had a plug fail, but caps have crapped out on me a couple of times.