Orite lads, lets try and sort your problems out on - 125/175 four stroke set up - first start by fitting 17.5 pilot jet, 102.5 main jet. set float height to 18mm (turn carb upside down, bottom off, gasket off, measure from base of carb to top of float). Also blow out the 2 small jets in back of carb to make sure that 145 is at the top and the 80 at the bottom as you can get them mixted up and causes it to run sick, the mixture screw should be set at 1 and 1/2 turns out, but this can vary.
Make sure there is ample play on the choke cable when turning handle bars lock to lock to ensure the choke is not coming on.
Removing exhaust baffles, only remove the 2 middle restrictor bars, DO NOT TAKE THEM ALL OUT!
Flywheel modification, standard is 2.1 kg, skim to 1.6/1.7 kg, this will improve performance at the bottom end.
If your bike is a long ride version, you need to contact me for the airfilter modification, but all the above aplies to the long ride also.
Clutch, there is a different hydraulic clucth kit available, (not Hebo) this is the best that you can buy, it gives the clutch a more progressive feel, this only aplies to the earlier 4-strokes as the new 05's come with an improved Magura system which equaly as good, but these clutch kits will fit on any year 125/175 long ride/racing models.
If you have any other problems, please do not hesitate to ring me at Birkettmotosport Uk Ltd.
Tel.01229-716806
Hope this has helped, Kev Seward.