Finally!
Posted: Sat Sep 10, 2011 5:23 am
I think I have finally found jetting happiness!
I've been dickin'round for months, I had tried a squllion different jet and needle combos, doodled with the ignition timing, different exhausts, different packers under the cylinder, different head gaskets and a blown out piston..
All in the quest of obtaining the sweet, sweet chocolate colour on the plug we all strive for..
I couldn't understand, with my standard engine set up I had the jetting dialled in text-book style, then I upgraded to a Mugello V4 and just couldn't work it out.. I was dead certain that there was something wrong with my cylinder kit.
I sat down and had a good think..A thought crossed my mind, surely going from a standard set up to an alloy kit with an expansion type exhaust the jetting wouldn't change super dramatically.
It was always crying lean..
Then it dawned on me..What have I changed...mixture screw, the aftermarket extended mixture screw...so I unscrewed it and compared it against the original, "damn you!" I exclaimed. Quite different down on the business end. It could only ever suck more air then it's meant to..
And that's where my had problem laid.. So I refit the original item, reset the pilot circuit and after of couple of hours of sorting the mid range I finally have achieved the sweet, sweet chocolate colour on my plug, maybe even a little rich, but I don't mind..
I've been dickin'round for months, I had tried a squllion different jet and needle combos, doodled with the ignition timing, different exhausts, different packers under the cylinder, different head gaskets and a blown out piston..
All in the quest of obtaining the sweet, sweet chocolate colour on the plug we all strive for..
I couldn't understand, with my standard engine set up I had the jetting dialled in text-book style, then I upgraded to a Mugello V4 and just couldn't work it out.. I was dead certain that there was something wrong with my cylinder kit.
I sat down and had a good think..A thought crossed my mind, surely going from a standard set up to an alloy kit with an expansion type exhaust the jetting wouldn't change super dramatically.
It was always crying lean..
Then it dawned on me..What have I changed...mixture screw, the aftermarket extended mixture screw...so I unscrewed it and compared it against the original, "damn you!" I exclaimed. Quite different down on the business end. It could only ever suck more air then it's meant to..
And that's where my had problem laid.. So I refit the original item, reset the pilot circuit and after of couple of hours of sorting the mid range I finally have achieved the sweet, sweet chocolate colour on my plug, maybe even a little rich, but I don't mind..
