I recently picked up a 04 Bet & Win 250. It had 258 km on the odo - seriously, it is like new for being almost 15 years old. Ran poorly, wouldn't come off idle under load. Figured it needed a good cleaning.
The guy I bought it from knew nothing about the scoots (there was a pair). He purchased them from someone who had them at their lake home. I have bought other scoots from similar circumstances - husband/wife bought a pair thinking it would be fun, but one or the other gets scared and the scoots are put away. Usually a very good buy for the person who falls into these type of sales.
So I get home and proceed to commence maintenance - clean carb bowl and jets, and change out all fluids. Plug is sooty black.
Still runs as bad, stinks, and seems to run very rich. Remove throttle cables for complete cleaning. Take thing apart and find spring and washer in mix screw missing, and accelerator pump diaphram is damaged. Give it all a good soaking in pine sol bath to further clean.
Ok, so now to source parts. Keihin CVK should be no problem, right? Not so. Cannot find these parts aftermarket, and the usual online parts vendors say parts are not available. Really? I see the Kymco parts fiche shows the B&W part numbers (all unavailable) are different from the People 250 and Grand Vista, which I ASSUME uses the same carb, and their tiny parts are available. Would they work on the B&W carb though?
I take the assembled carb to a local, independent bike repair shop. The owner's son walks by, takes a look at what we were trying to find and gets a carb from a Genuine Buddy 125 from their used parts. Other than a 24mm throat, it looks like it is the same Keihin body. The mix screw pieces and the diaphram looks the same; I end up installing them on my carb.
Reinstall on the B&W, go for test drive. Scoot comes off idle and accelerates fine, but I have a bad midrange stumble under load or not. I am stumped.
On another forum I catch a thread about Keihin CVK carb problems on a guy's ATV. Someone posted a video about the Harley CVK carb, and it points out that quite often the "needle jet" is lost while cleaning. The "needle jet" is a "sleeve" that fits between the float chamber and the throat, and is held in place by the emulsion tube/mj assy. When the emulsion tube is removed, this tiny part can fall away undetected. If it is missing, excess fuel will be introduced into the throat - causing a very rich mixture.
I pull my carb again. Yep, my needle jet is MIA. It is easy to tell because it slightly protrudes from the throat where the needle enters the float chamber, and I just had a hole. Off to the shop, and we pull the needle jet from the Buddy carb and put it in mine.
I install my carb again. Luckily, it was a decent day for test drive - a sunny day, kinda warm for the day after Thanksgiving. Scoot seems to run perfect now - put about 20 miles on it. Pretty sure that is it for riding this season - a half foot of snow is on its way tonight.
Hopefully this is not TLDR. Carb notes for the Keihin CVK 30 from Bet & Win:
-The body of the CVK 24 from the Genuine Buddy 125 is mostly the same (no airvalve or TPS). Looks like the small bits are the same as with the CVK 30. Parts are less expensive than thru Kymco.
-I looks like the same carb is used on the Kymco People 250 and Grand Vista. Need to have this verified, and jetting may be different.
- Same, or very similar carbs are on the Burgman 250, some Arctic Cat sleds, Kawasaki ATV's, and I'm sure there are others. Might be a parts source from them.
Plenty of parts avail on the web for Keihin carbs, but hardly anything for the CVK models with the exception of the ones used on HD's. Would love to see if you have any sources.
