Slower and slower XB-600
Help! I got my XB-600 on Thursday, put it together (no small spacer for the front fork, but I installed te wheel without it anyway... it looks centered, the wheel rotates without rubbing anywhere and the brake works fine, but I'm ordering a replacement spacer anyway). Rode to work on Friday: 15mph top speed on the way to work (stop & go... no big hills). Rode home: windy, and top speed dropped from 15mph to 12mph. Battery still read half-full so I rode it Saturday: top speed of 10mph (on flat surface... no wind). Charged battery overnight (8 hours). Sunday morning: power meter reads full power.
TOP SPEED: 12mph!
I checked the grey "governor" wires: they were disconnected so I tried connecting them: TOP SPEED 5mph! Disconnected them and the top speed went back up to 12mph.
Headlight, horn, blinkers and brake lights all work.
What could be causing this poor performance?
Any and all advice is welcome.
Try putting the scooter up on the jack stand and spin the rear wheel. Mine spins easily with little resistance, but does not continue to spin very long. Get someone to sit on the scooter toward the rear so the front wheel is off the ground and do the same thing to the front wheel. Check to make sure the chain it not too tight. I have mine adjusted so it has about half an inch of play when you push the chain up and down from the middle. After riding for 5 minutes, stop and put your hand on the chain side of the motor and feel how hot it is. It should be no more than mildly warm. If it is hot to the touch, you probably have some high rolling resistance. Check to make sure the rear chain sprocket is tightened all the way on the wheel.
Glenn
The batteries could be another source of the problem. I was having a low speed problem with my XB-600 right out of the box. My problem turned out to be the governor wires were connected. Before figuring that out with the help of this list, I went through the process of diagnosing this with X-Treme. The first thing they suggested was replacing the batteries. They sent new batteries. In my case the new batteries did not seem to make much difference; however, a guy at X-Treme told me that all 4 batteries that I returned which originally came with the scooter load tested either bad or nearly bad. Since the batteries are in series, it would only take one really bad or shorted battery to leave you with only 36 volts, which could explain your symptoms. Try checking the voltage on your battery pack.
Glenn
I know this isnt solving the problem but with Sealed Lead Acid batteries, it is best to charge them as often as possible... you mentioned you didnt charge since they were half full, but discharging below 50% on SLA batteries is supposed to damage the battery... also you go faster if you're fully charged (but it shouldn't make that much of a difference... theres obviously something wrong)
Check to make sure the chain is not too tight. I have mine adjusted so there is a half inch of play in the middle of the chain. Also, check that the rear chain sprocket is threaded all the way onto the wheel. If the chain it too tight, the friction in the rear sprocket can cause it to untighten until it starts rubbing against the swing arm.
The only other thing you can do is try to see if you can detect if anything that moves on the back wheel is making contact with any stationary part of the scooter. If the rear wheel has any significant resistance to turning, that could be whole problem. Another tip off would be if the motor is getting hot. If you ride it for 5 minutes any put your hand on the motor cover or touch the axle with your finger, it should be no more than very mildly warm. It should not be at all hot, in my experience.
Glenn
Check your rear brake to make sure it is not adjusted too tight. You could try disconnecting the rear brake cable completely and if the wheel spins freely then. If so, the brake cable is adjusted too tight.
Glenn
Great to hear :D




Thanks, Glenn...
I tested the bike on the stand and it showed no improvement. I will check the voltage. I did notice that applying pressure (up or down) to the throttle had a minor impact: it increased the speed by a discernible amount (maybe 1-2mph). But I took the speedometer assembly off, as well as the throttle and the wiring looked good... no crimps, bare wires or other signs of catastrophe, so I'm digging out my old multimeter...
Thanks again for the help.
Flick