L1 600 performance questions again
Last fall I posted about getting less power off the line, revving up didn't sound the same, slight backfires when shifting around 7K+, and that my mileage dropped from 45 to 35 mpg.
Over the winter I replaced the dirty air filter, gapped and properly torqued new plugs and put in fresh oil and filter. The bike was stored in my basement and the gas tank had a strong dose of fuel injector cleaner and Stabile in the 90 octane ethanol free gas. This April I got the bike out. First fill up was with the 90 octane ethanol free again. I don't know what the mpg was because my app crapped out. Next fill up i filled with 93 octane with ethanol. At that the next fill up I found the 93 got me 48 mpg! I thought the problem was fixed!! Next fill up I used 90 octane ethanol free again and mileage dropped to 38 mpg, again, about the same as when I complained last fall.
I still feel like the bike is a little loagy below 5,000 especially in third or fourth gear. When I got the bike I could cruise town at 35 in 4th at around 4,000 rpm and the bike was nice and mellow.
I am stumped as what to check.
Bike has a little over 15,000 miles and the only performance mod is that Jardine GP1 slip-on. Any help will be appreciated!