Px200 carb set-up

Had a problem with my px200disc, (2001 model std 24 mil carb, simonini exhaust)

was running rich, on both 116 & 118 main jet changed cleaned filter, plugs(NGK 6 to [H] and adjusted the mixture screw. Got running fine by plug colour, however when in top gear at 3/4 moving up to full throttle, feels as if sticking / not firing right, more so when uphill or into wind. When I adjust the mixture to more rich this goes away but then is running too rich and fouling plugs on the 116 jet???

Any ideas on what to try next, or what this could be

Thanks in advance, Malcolm


check out the hole in the seat above the filler cap. you will find that when you sit on the seat the foam is pushed through the hole slightly and seals the vent in the cap causing all sorts of jetting problems. i found that fitting a small spacer between the seat base and the foam cures it. i used an old oil seal cut through one side and fed into the hole worked fine. give it a go and let me know if it works for you.
paul D[:D]

Hi md999,

Have you made sure that the hole in the frame
under the seat isn’t blocked, worth a try.


clutch side seal on its way out

Guys thanks for the response have tried the air route to no avail and as I say this only happens in top gear.

However the clutch has recently been changed and they may have bodged the seal, is there any easy tell tale signs. There is no oil show at the clutch side.

The only thing it reminds me off is in a previous life going to exmouth in the pissing rain and driving down that river called the M5, when it started pulling and eventually backfiring. That was down to the CDI getting soaked. Could it be a dodgy CDI or would this also show in each gear. If so is the CDI on a PX200 the same as T5 to try a swap over?

Thanks, Malcolm

Had a similar thing a while back. Kept a pair of waterproofs under the seat. Felt like running out of fuel, I would check fuel level which released vacuum, and run ok for 5 miles then start again. Didnt twig for ages, and tried, I thought, everything to cure it. Boy did we laugh once we’d figured it. NOT. May be worth checking flow from pipe and check filter in carb too.