running rough

[max]

Ok so here's the problem...after rebuilding the carbs on my
1981 GS850, things were running great. Only problem was kind of a dead spot between 1800 and 3500rpms where it would just accell slowly, after that it was all good. So I just let things slide.

Now its been getting progressively worse since then. Hard cold starts in the morning, backfiring while coasting in gear, and inconsistent idle. Sometimes it will idle around 3000, and I’ll reach down at a red light or something and turn it down¸ and sometimes it will die out if I don’t turn the idle screw up.

Now the starts are getting harder and I’ve got less power than I should. In short, it’s just running pretty rough. Here’s what I’m thinking…

It’s not the plugs, just replaced them. However, the spark is pretty weak. I had my induction coils tested and they are good, what else should I look for?
I also never coated the inside of my tank, is it possible that in 2 months its time for another carb cleaning? (I f-in hope not)
What else could it be? What should I be looking for? Right now its pretty much my only source of transportation, so any help you guys could offer would be really great. Thanks

[Poot]

well, it sounds like theres possibly something in the jets. i had a similar problem. my carbs were sparkling, but there was a single piece of debris in one of my main jets that was making things worse.

other than that....clean your air filter, and change/remove your inline fuel filter if youve got one.

[anvilman]

trash

it could be some trash in the jets not letting the air and fuel mixture blend right or could be a tiny hole in the diaphragm

[max]

so, definately a carb problem? anything in the electrical system i should look through?

[mark]

Hows your battery? If you battery is getting progressively weaker that might be leading to the harder starting and weaker spark. A good battery is essential for your ignition to be working rightl.

A lot of your symptoms (bikefiring, hard to adjust idle) point to lean carburetion. If your bike really has straight pipes on it and you haven't done much carb adjustment work, that's a part of your problem and the "flat spot" you described.

If you have a rusty tank, your petcock screen could be plugged. You're petcock also could be drawing gas through the vacuum line, that would cause rough running as well.