Topic: Running rough after new (to me) gas tank

[zachiepie]

I'm having an issue with my previously well-running 82 CB650SC. My old tank was rusted beyond repair, and I found a new one on eBay. The tank looked like it was in great condition, and as far as I could see, there wasn't any rust on the inside of the tank. I installed it, put gas in it, and ran it. During my next ride, the bike acted up. It sounded like it was misfiring, and it would die when I idled it at a stop sign or wherever. I got it home, and the left cylinders did not seem to be firing. The exhaust pipes were cold, and the carbs were full of gas when I drained them (to make sure they were getting gas). When I inspected the gas that came from the left carbs, I noticed a bunch of reddish appearing flecks. I didn't see any on the right hand carbs.

I installed a new inline fuel filter (to replace the old one) and revved it in the garage to higher RPMs. I still can't get those cylinders to fire right. There is spark and I'm still getting gas in the carbs.

Is my only option now to remove the carbs and clean everything out?

[ekpent]

 Sounds like a good place to start if a significant amount of rust came out when you drained them. Slow jet holes are very small. Make sure your offending plugs are not fouled and getting good spark. That is an easy test to do first.

[RandomOrbit]

Seems likely you have clogged jets on that side. Why not pop out all 4 right side jets and check them for clogging. You don't need to remove the carbs from the bike to pull the jets. Idle jets in particular would be easy to clog with a piece of rust.