Fantic 200 Pro Carb Problems

[bambam_n_chunx]

I`ve rebuilt a 200 pro with forward kickstart, the engines had a complete rebuild with new mains seals and ring.

The carb that came with it was wrong so i`ve sourced a 25 mil dellorto and set it up as the info on tc would suggest is right.

its a pig to start and wont tickover which suggests its running weak.

The spark is perfect and timing is spot on, and once started it runs well on high revs just when the throttle is closed it bogs down.

Obviously the carb is spotlessly clean so not a blocked airway or jet.

Any ideas?

It has a 90 main,48 pilot and 60 starter jet. D33 needle on 2nd groove and 40 slide.

I need this sorted as I need to sell it to make room for another project.

Edited January 29, 2014 by bambam_n_chunx

[eddie1]

Hopefully someone will have the answer to this. I suspect the problem is somewhere on the pilot jet mixture screw.

Have you got the right slide for your bike in the carb and are you sure there is no air leak in the manifolds.

One other thing is if the silencer is blocked/choked up it really strangles the bike at low revs. I would have thoughit would have been more noticable at high revs but it was not the case with mine.

An easy check for this is just to disconnect the rear box or at least unseal te joint between the expansion pipe and silencer.

I rebuilt a 200 rearkicker which ran great but I could not get it to stop bogging down when rolling the throttle back on from tickover.

I tried a few different jets etc. but in the end just bought a new dellorto carb set up to Fantic standard jets and slide. End of problem bike runs great.

A new 25mm carb can be bought cheap off ebay but as far as I could see they have all the wrong jest and slide. I bought mine from dellorto uk but noticed that Inmotion will set the carb up to your spec as well and were a few quid cheaper.

Good luck