Hey. I got a Beta Rev3 from around 2002-2003- with a 250 ore 270 cc engine. It runs very well at idle , but when I speed,  it begins to shoot in the exhaust and go bad . What could this be? I have new spark plug , fresh gasoline . cleaned the carb . Im not sure if the pilot jet is correct adjusted. I did try first with 1 round, then 1,5, then 2 and then 2,5 and then 3 turns, but nothing helped.  Any tips?

 

Second thing, Im not sure how old this bike is, i got a frame number x ZD3B9000Y0002660 x  Anyone who can help me translate that frame number? On the engine side its written 352C/1 0 1/1. It go ta Mikuni carb

 

Just to be sure, The pilot yet is the little screw i mark with a red dot on the picture right ?  

 

Thanks from Norway!

On the lower photo', is that a water droplet in the clear tube? Might be worth draining the tank and carb' and making sure it's nice and moisture free.

Its a 2001 

Sounds like its running rich as the revs rise, is your air filter clean?

The one that's painted is your Air screw not pilot jet,normally set at between 1 1/2 to 2 1/4 turns out.The pilot jet is inside the carb,

You need to pull the flywheel to make sure you did not shear the flywheel key.

Hi, I had a similar issue with my rev3 a few years back, turned out to be a grounding issue where a wire had rubbed off the frame until the insulation was removed on a small position. The core of the wire would contact the frame under vibration and cause a misfire. Worth a look, pull the radiator out to get good access to wires behind head stock and check them all for damage. You can use electrical tape as a temporary fix on the damaged section to help determine if it's the cause of your issue.

Hi, I had a similar issue with my rev3 a few years back, turned out to be a grounding issue where a wire had rubbed off the frame until the insulation was removed on a small position. The core of the wire would contact the frame under vibration and cause a misfire. Worth a look, pull the radiator out to get good access to wires behind head stock and check them all for damage. You can use electrical tape as a temporary fix on the damaged section to help determine if it's the cause of your issue.

Its a 01

I also have the exact same bike, with a carb issue it's running really rich, can someone tell me the settings on the carb screws please. And also the fuel on/off switch I suspect is broken does anybody know the positions the switch should be for fuel on/ off / rez??