I spent a couple hours this morning replacing the belt on a Bet and Win 250 and thought you all might want to have a look-see. To give you an idea of who I am, I'm a newcomer to scooters and have limited experience working on engines. I purchased my B&W last September used with 11,000 kms. It's been my daily commute vehicle since about the first of the year and drives pretty much flawlessly. Having no idea if the belt had been replaced, I decided to give it a try. After all was said and done, I'd rate this job a 4 out of 10 in difficulty - adding an extra 1 point because of the spanner wrench as discussed later on.
First, the tools: Phillips screw driver, a couple extensions, socket drive adapters, 8mm, 10mm, 19mm sockets, assortment of socket wrenches, breaker bar, torque wrench, and a homemade adjustable spanner wrench.
The spanner wrench is a story by itself. After looking on line and at the local dealer, the prices were too high or I had to buy other things which I did not need in order to fulfill a minimum purchase requirement. Instead, I found a lock nut wrench at Home Depot in the plumbing section for $10.75, drilled and tapped a couple 5/16-18 holes and screwed in the respective bolts (1" long). To match the diameters of the holes I took a file after the threads until they fit nicely in the drive pulley. Total cost, ~$12 plus an hour of work. Looking back, 1/4-20 bolts would probably work fine and you wouldn't have to file the threads - just let 'em get mashed.
Obligatory disclaimer: I followed the Kymco repair manual for all steps and you should as well. Everything here is supplied as a report of what I did and since I am not a trained Kymco repair person, it is up the reader to verify the proper steps are indeed used.
OK back to the belt replacement: The outer cover removal is straight forward. Remove the 4 bolts holding it in place (10mm socket), loosen the rectangular clamp for the air duct, and disconnect the breather tube. The breather tube had ~1" of gas/water/dirt mix which got drained.
Next, remove the crankcase cover by removing the 6 bolts using the 8mm socket. It slides right off and is easy to remove as well. I had removed these covers previously in order to size the spanner wrench bolts. The first time I removed the crankcase cover, I did a minor boo-boo. I grabbed around the crankcase cover while removing it, not realizing the gasket was on the other side. I broke the gasket where it is unsupported - it is quite brittle. After surveying the situation, I realized it doesn't seal anything where I broke it so I elected to re-use it.
Next, remove the drive pulley bolt and remove the outer pulley half. The spanner wrench worked well - as shown the rubber handle rested on the clutch housing during removal.
Next, remove the driven pulley/clutch assembly. I used a cinder block to support the spanner wrench for this step.
After removing the driven pulley/clutch assembly and the other half of the drive pulley assembly I spent about 15 minutes cleaning out the crankcase.
I'm a bit of a neat freak, so I spent a significant amount of time cleaning all components during the process. I replaced the rollers as well as the belt and reassembled the crankcase in the reverse order. Here's tightening the driven pulley/clutch assembly bolt. Note, I realized after I took the picture I needed to get out the torque wrench. I set it to 70 ft-lbs and used that instead of the breaker bar.
Here's the set up for tightening the driven pulley bolt.
One note during re-assembly, getting the outer cover on is easiest if you put the breather tube on first, bolt the cover in place, then put the air duct on.
All in all, it's a simple job. It took about 2 hours including taking photos, moving slowly to avoid mistakes, and taking time to clean everything during the removal process. I'm sure the time can be reduced significantly, particularly now that I have a spanner tool and have been through it all.
Happy scootin',
Eric
