Stumbling, weak power and backfires upon acceleration.
Posted: Mon Sep 19, 2016 4:02 pm
I've been busy and have neglected my poor EN500C lately. She has been unused for far too long. A few days ago everything seemed normal when I first started her up then a mile or so down the road she started backfiring like crazy and acting like she was out of fuel or running on 1 cylinder or running very lean or some combination thereof. Basically what the subject describes and somewhat similar to how another carbed bike I had ran when I decided to try E85 not knowing any better. WOT and barely accelerating past 40mph. I'd back the throttle off and then it was like the second cylinder would kick in and would stay that was as long as I didn't go on the throttle too much. I initially suspected a my carb was gummed up from sitting too long. Then I thought I had an ignition system problem. Last night I added a few ounces of acetone to about a 1/3 full tank. Acetone being a strong solvent I'd hoped would help disolve gunk in the carb and get things flowing right again. I then went on a 40 mile ride mostly 45-70mph. At first I stayed in 3rd or 4th gear to keep the revs up(6K+) and varied the throttle to provide varying amounts of suction to hopefully help suck the gunk out that is mucking up the carb. It took about 3-4 miles till it was "running on both cylinders" I put that in quotes because I really don't know what it was doing it just felt like that. After It felt normal at least some of the time I brought the revs down and used the higher gears. By the end of my 40 mile ride it was almost back to normal. Today it's still acting up but is much better. So I'm fairly certain it's just my carbs gummed up and hopefully running enough gas thru the carbs will dissolve the gunk. I'm contemplating putting some 110 octane racing fuel in it to see if that helps because that is the only fuel I can find that is ethanol free around here. Hopefully this or just running more gas thru the carbs will remedy this and I won't have to take apart and clean my carbs.