I've got a rack of FCRs that started sticking on me randomly. I've got some tuning issues to sort, I know the carbs are old and worn, so they're getting boxed up for a trip to Sudco for a full rebuild before I try to chase anything else. In the mean time I'm I'd like to figure out why they're getting tacky from the start of the stacks to the end of the intake side spigot. I can feel a bit of the same issue in the intake tracts of the bike but not as severe. Bike has had Shell 93, Sunoco 93 or 260 GTX only, tank is drained at the end of the day, no additives/etc. (I'm now restricted to just Sunoco or VP fuels in LRRS, motor is built and tuned for pump gas.) None of my other machines have done this to me. The only thing I can think of is something is leaching out of my CF tank? Any thoughts?
Stand off. The 260GTX tends to be a bit gummy when the carbs spit it back out. Does the same thing to throttle bodies.
racepro, I think you're on to it. The problems started after I used 260GTX for one weekend thinking avoiding ethanol would be better for my ancient tank. Bike ran fine, tank was ok. Next day while going over the bike in the garage, I noticed the slides were sticking after being left closed over night. Once broken free they were fine until the bike sat again. I blamed it on the 260GTX, asked a couple friends running it on their FCR equipped bikes and they didn't experience the same issue. Looking over the bike further I found some of the green dye from the gas on the side of the tank but assumed it was due to me spilling some that weekend. I tested the tank with pump gas afterwards and didn't see any signs of a leak but I also didn't leave the gas in for a full day. The next outing for the bike was this weekend, I switched back to regular 93 hoping to avoid the initial closed sticking I found. Instead, the slides progressively got worse, randomly sticking open unless forced closed via my push / pull throttle (you'll never convince me to go pull only now) and the tank started slowly leaking anywhere there was a surface imperfection after holding gas for a few hours. I had assumed the two were separate issues, the tank has been beat and repaired multiple times before I got it so it's always been questionable. I was under the impression that if the epoxy failed it'd leak or flake off, both of which are occurring. It wasn't until I poked at the carbs and noted they were tacky all over that I started contemplating the two problems being linked but it sure makes sense now. My only question is did the 260GTX really trigger the tank failure, or was it just a matter of timing, the 260GTX happening to be in the tank when the epoxy finally gave way?
just pull the carbs apart and clean them. As noted above, clean and lubricate the wheels on the slides. I'm not a mechanic, but found the FCR really easy to work on.
