Fuel Pump Observations
The 2012 Wee was my first ever fuel injected bike. I have been riding a KTM 450 EXC for the past 5 years, so when I pulled out of the dealer it was like riding a quiet electric scooter. No chain rattle, no single piston pop pap, just smooth as silk gliding down the road.
Rode it about 20 miles before I heard the higher pitched weeeeeeeee. Almost sounded like something plastic was rubbing up against the front sprocket. I quickly realized that when I let off the gas the sound went away.
Coasting was quiet but if I gave the slightest bit of gas the sound returned. I had two bars left on the fuel gauge as I started to think to myself "fuel pump". I went to a gas station and filled up. The sound did not go away when I took off. It was an 80+ degree day with the sun hitting hard so I just kept riding and tried to ignore the unpleasant sound. I made it home, did a couple more rides and the sound never went away.
Took her out the next morning and the sound was gone. Quiet like the first ever ride. I went on-line to see if anyone else had the problem and the older Wee had the same problem. People said that the gas cools the pump so don't ride around all the time close to empty. I then was filling up all the time, but some days sound was there others quiet.
I finally realized that the gas temp was the reason for the noise. When I took her out in the morning I never heard the sound. If I let the bike sit for 10+ minutes and then took off and/or rode on a super hot day in the sun the sound came back.
If the gas in the tank temp heats up then it is not cooling the pump enough so I got the "plastic on chain" sound. It is not that bad, but annoying enough to be bothersome on longer rides.
I'm sure I'll forget the post when it starts to get cooler but let me know if anyone else experienced this slightly annoying problem.