Hi guys, So a quick run down of my engine spec before we go into the technical questions. -2.0 9a block -2.0 16v ABF head (very very mild port) -276 inlet, 288 exhaust cams (TSR) -Kent vernier pulley set to around 3 degrees advance. -Megajolt ignition system (ford EDIS 4) all timed up correctly running a map hopefully suited to the engine (off a similar setup with less cam) - YZF1000 carburettors, same as r1 but have a 38mm vent. -180 main jets, standard pilots, standard needle position, float bowl level pretty close. (now 4 and turns out) - 4/1 manifold and 2.5inch system all the way back, no cats. Over the weekend I had the beast fired up and running to set the timing, with this set I moved on to check the CO, with a gas analyser. I know my gas analyser pretty well and hope to see 1.2-1.5 CO reading minimum, upto 2.0 ill be happy with until I put my wideband lambda on the car. With the car idling around 700-800rpm, I was seeing 0.30/0.40 CO, now this to me is stupidly lean, so I proceeded to wind OUT the fuel adjustment screws by 3/4 of a turn each. This now leaves my mix at 4 and 1/4 turns out (seems excessive). After this adjustment I was still seeing the same CO reading, if anything even slightly leaner? Also if any help, when you rev it, it revs happily once warm but hangs a few seconds before the revs drop, indicating its lean? Now my questions are Do I need to change the pilot jets? Do I need to have a reground needle? Should I adjust the needles on the cir-clips up a level? Bigger mains (180 should be enough so I dont just want to keep chucking bigger and bigger jets in) As soon as its fueling better, ill finish bleeding the new brakes, install the wideband and finish tidying to get it moted. Thanks in advance.
I know how sensitive my 2L16v is to pilot jets on webers, so I would say yes, much bigger pilots. However, I have no experience of bike carbs. Bogg brothers? Jon
Thanks guys. Looking at the way in which the carbs work i guessed it would be pilots or a needle lift, as on tickover the needle blocks the main jet up untill you create some vacuum by revving to lift the needle out the main jet.
