fresh tune up! ran great... for a while, bogging backfire

[Milktown]

78 gs750. Just cleaned carbs, new points new plugs new air filter, chain sprockets clutch plates all that good stuff. Everything was running great went from about 36 mpgs to 39. The Guy who had the bike before me had these goofy Harley mufflers put on so I took em off was running with just the headers(cut off right behind footpegs). I know people say its bad to run with just headers but from what I got it seems like more of a myth? Anyway I ran the bike like that for a few days mpgs went up to about 40-41 everything was going great until last night. Went out for about a 50mi ride and towards the end it started bogging and backfireing on one of the two left cylinders (sitting on the bike). Is this cuz of the headers I was only running like that till I got the new pipes? Or you guys think this is a Carb, electrical issue.

[terrylee]

I would check your coils and all connections to them (best to just replace), might do relay mod. for coils if haven't already. I had similiar problem and turned out to be one of the coils was bad. Would run ok till good and warmed up and then bogging and backfiring. Got so it finally did it all the time. Replaced both coils and replaced all connections, and it ran great on the way to work this morning. (first ride since repairs). terrylee

[Milktown]

I would check your coils and all connections to them (best to just replace), might do relay mod. for coils if haven't already. I had similiar problem and turned out to be one of the coils was bad. Would run ok till good and warmed up and then bogging and backfiring. Got so it finally did it all the time. Replaced both coils and replaced all connections, and it ran great on the way to work this morning. (first ride since repairs). terrylee

Yeh I was leaning towards electrical too. Unfortunately new coils for the bike are upwards of $150. Maybe il try to get my hands in something used... let me know how your bikes running the next couple days.

[Guest]

Hopefully you didn't lean the bike so much that you melted something.

[tkent02]

I know people say its bad to run with just headers but from what I got it seems like more of a myth?

No, it's not a myth. Too much air and not enough fuel equals burned valves and holes in pistons.

Hopefully you didn't lean the bike so much that you melted something.

And yet another GS dies a sad death due to neglect and ignorance.

[Big T]

Did you replace the condensors as well?

That's what it sounds like to me