Chuck Hahn
CB750 Enthusiast
Bikes a 79 CB 750K. I rebuilt the carbs with all new accelerator pump, new rubber plugs over the one jet ( dont know its proper name) thats long and comes to a rounded end and sticks into the bore of the carbs, dipped the bodies in Berrymans for 24 hours. Ran a few cans of carb spray into all the openings and lots of compressor air as well Took a fine wire and poked out all the holes in all the jets.
So heres my problems. I set the float hts at the 15.5MM that manual calls for but 3 and 4 will still start dripping out then overflows. Yes, they are new rubber tipped float needles as well. Whats the HIGHEST I can set a float at and have it not be lean due to fuel being too low in the bowls???
Second, it wont idle down like a hanging idle if theres air leaks at the boots but some starter fluid sprayed on them doesnt change the RPMs so I think its not air leaks I got a Carbtune pro and then sync is very very good...all 4 almost exactly the same. I put new NGK plugs in and after it ran a few minutes i took them out. 1 and 2 looked OK, but 3 and 4 had white ashy look on the bent electrodes. Manual says a possible cause is clogged jets so I yanked the carbs yet again and nothing was clogged in any of the jets. Seems wierd that all 4 bodies got the same dip time and cleaning procedures and two are showing fine plug color and two are ashy white...what gives??
And third is the timing. Looking at the marks on the advancer there are 2 marks close together with an "S" to the left of them Then the "F" just to the right of the 2 close together marks. If I am understanding the manual correctly, when you put the timing light on the indicator at the top of the cases falls between the 2 close together lines?? Can someone further explain where the indicator falls because the online manual i have is kinda hard to see clearly exactly where I am supposed to get the point of the indicator to point at.
So heres my problems. I set the float hts at the 15.5MM that manual calls for but 3 and 4 will still start dripping out then overflows. Yes, they are new rubber tipped float needles as well. Whats the HIGHEST I can set a float at and have it not be lean due to fuel being too low in the bowls???
Second, it wont idle down like a hanging idle if theres air leaks at the boots but some starter fluid sprayed on them doesnt change the RPMs so I think its not air leaks I got a Carbtune pro and then sync is very very good...all 4 almost exactly the same. I put new NGK plugs in and after it ran a few minutes i took them out. 1 and 2 looked OK, but 3 and 4 had white ashy look on the bent electrodes. Manual says a possible cause is clogged jets so I yanked the carbs yet again and nothing was clogged in any of the jets. Seems wierd that all 4 bodies got the same dip time and cleaning procedures and two are showing fine plug color and two are ashy white...what gives??
And third is the timing. Looking at the marks on the advancer there are 2 marks close together with an "S" to the left of them Then the "F" just to the right of the 2 close together marks. If I am understanding the manual correctly, when you put the timing light on the indicator at the top of the cases falls between the 2 close together lines?? Can someone further explain where the indicator falls because the online manual i have is kinda hard to see clearly exactly where I am supposed to get the point of the indicator to point at.