Kymco carbs and Kymco jets

[JJJoseph]

Has anyone here managed to source jets for Kymco carburetors?  My Kymco came with a 20mm Kymco carb that's an exact duplicate of a Keihin CVK carb, with one major difference: the jets are not Keihin jets.  So it can't be tuned with standard Keihin jets.  It starts and runs OK with the Kymco clone carb, but idles like a lawn-mower at 3000rpm.  At slower speeds it misfires and stalls.  It would be any easy fix if I could find after-markets jets in different sizes.  Kymco doesn't offer jets.  The only remedy is to swap the Kymco carb for a genuine Keihin - which is expensive!

Any ideas?

[Iahawk]

JJ, that was not my experience with my S200 carb. The jets I removed were identical to the Keihin jets I replaced them with. It worked fine.

Here's a link to the site I used, Jets R Us. I haven't looked at the prices in a few years..WOW!!! Almost $20 USD for 1 pilot jet?? I recall buying them for around $6 USD?

https://jetsrus.com/a_jet_kit_scooter/honda_250_CN250_helix.htm

[Ruffus]

AFAIK these are all M5 jets. I buy them at AMAXON as a bunch for
€ 14 ,- the set of 15 pieces. Didn't have any trouble neither at KYMCO (Kei*hin) nor at Moto Guzzi (Delorto) carburators.
Inexpensive, so at a carb service I usually drop old ones for new jets.
Different sets (lower from 30 to 70)  (higher see pic) available. Overnight delivery.

[JJJoseph]

Thanks for the replies.  What you say has largely been my experience - until I opened my Sento 20mm Kymco carb.  And this is what I found: I've never seen these jets in any known parts bin!  PS: No idea why the image goes upside-down!

[JJJoseph]

And here's a view of the Kymco 20mm carb with its trousers off.  The reason I'm fussing with it is because it's really fast - about 20kph faster than the Keihin, winding up to 9500rpm. I only get about 7500rpm out of the more lady-like Keihin.

[Ruffus]

IMHO, main on the pic is jet stock with jet in it
-jet (red arrow) should be M5 thread and come out to be changed
-hold against with a 9mm ring spanner and take the main jet out with a sturdy flat screwdriver

[Iahawk]

that was my first thought, too...that you pulled the entire main jet with emulsion tube out. The main jet will separate from that tube, per Ruffus's drawing.
Other than that they sure look like regular Keihin jets?

[JJJoseph]

IMHO, main on the pic is jet stock with jet in it
-jet (red arrow) should be M5 thread and come out to be changed
-hold against with a 9mm ring spanner and take the main jet out with a sturdy flat screwdriver

You're right! I got out my magnifiers  and vice-grips and did as suggested. Up to this, my Kymcos have always been M4 jets.  This thing requires a 7mm open-end spanner and M5 jets. A box-end spanner doesn't fit. Never, until now, have I ever needed a 7mm spanner for anything.  So I'm off to buy a spanner and some jets!  Thanks to all for good info:-)

[randyo]

quite frankly, I wouldn't waste my time on jets for a 20mm carb, small carbs are cheap enough, I'd just go up to a 22mm carb going up more I'd start looking at the exhaust too