Daegan
Member
I have seached a lot lately to find out more information on original carbs. I am not sure what a "533a" carb is specifically, what else there was out there originally by year/model, what exactly I have, or what is a good replacement carb/Jetting for my year and model. According to DrAtv:
THE STOCK SIZE JET FOR THE Z50 HARDTAILS IS 50 JET, MAIN (#50)
THE STOCK MAIN JET FOR THE 1970 CT70K0 AUTO IS (#62)
THE STOCK MAIN JET FOR THE CT70HKO IS #60
THE STOCK MAIN JET FOR THE CT70HK1 IS #58
THE STOCK MAIN JET FOR THE CT70K1 TO 1977 IS # 58
THE STOCK MAIN JET FOR THE CT90K0 AND CM91'S WERE #72
THE STOCK MAIN JET FOR A 1978/79 CT70 JET, MAIN (#55) 99101-116-0550
The way I see it, if I put an after market carb that is for "KO-78" on my bike then I have some jet size considerations to make in addition to the air boot into the body remaining as well. Can anyone out there elaborate on what should have come (Carb part Number) on an HK1 standard? What is the history of these carbs? Also, all other things considered equal; when replacing with an after market carb, should not those factors of jet size still be relevant?
This is what I have:
Red HK1 original carb with a #58 jet dialed in and runs great
Yellow HK1 with an (Identical looking) after market carb (very clean), #58 Main jet, idles fine, carb was cleaned by following a tutorial on this forum, smooth/consistant throddle, but very little top end like it just doesn' want to "open up". This bike has plenty of torque but I do not know the compression (I know:buy a tester). Very low miles on it and the head was rebuilt a few years ago as it was frozen in hibernation back then. Valves are set correctly, new points/timed. Have adjusted the throddle needle back to the middle notch. Cam timing was checked and perfect. Spark plug is great/new/gapped. The advance on the flywheel appears to be functional and no different than the other bike. Runs well, just no balls. Am I missing something like a cable adjustment or some other item? I have read about air flow being different and particular for some carbs.
I am in the high desert of Arizona, in the pines at about 5,500 ft. Temps are moderate with 70 degrees being the time of day I attempting adjustment/diagnosis.
I suppose I could swap carbs and see if that is the difference but that still leaves me with what I do with this after market carb to make it perform if that is the case. Thanks for any info or suggestions.
THE STOCK SIZE JET FOR THE Z50 HARDTAILS IS 50 JET, MAIN (#50)
THE STOCK MAIN JET FOR THE 1970 CT70K0 AUTO IS (#62)
THE STOCK MAIN JET FOR THE CT70HKO IS #60
THE STOCK MAIN JET FOR THE CT70HK1 IS #58
THE STOCK MAIN JET FOR THE CT70K1 TO 1977 IS # 58
THE STOCK MAIN JET FOR THE CT90K0 AND CM91'S WERE #72
THE STOCK MAIN JET FOR A 1978/79 CT70 JET, MAIN (#55) 99101-116-0550
The way I see it, if I put an after market carb that is for "KO-78" on my bike then I have some jet size considerations to make in addition to the air boot into the body remaining as well. Can anyone out there elaborate on what should have come (Carb part Number) on an HK1 standard? What is the history of these carbs? Also, all other things considered equal; when replacing with an after market carb, should not those factors of jet size still be relevant?
This is what I have:
Red HK1 original carb with a #58 jet dialed in and runs great
Yellow HK1 with an (Identical looking) after market carb (very clean), #58 Main jet, idles fine, carb was cleaned by following a tutorial on this forum, smooth/consistant throddle, but very little top end like it just doesn' want to "open up". This bike has plenty of torque but I do not know the compression (I know:buy a tester). Very low miles on it and the head was rebuilt a few years ago as it was frozen in hibernation back then. Valves are set correctly, new points/timed. Have adjusted the throddle needle back to the middle notch. Cam timing was checked and perfect. Spark plug is great/new/gapped. The advance on the flywheel appears to be functional and no different than the other bike. Runs well, just no balls. Am I missing something like a cable adjustment or some other item? I have read about air flow being different and particular for some carbs.
I am in the high desert of Arizona, in the pines at about 5,500 ft. Temps are moderate with 70 degrees being the time of day I attempting adjustment/diagnosis.
I suppose I could swap carbs and see if that is the difference but that still leaves me with what I do with this after market carb to make it perform if that is the case. Thanks for any info or suggestions.