82 cb 750 carb info

[clarksco]

have a 1982 cb 750 breaks up around 7k rmp have done all the obvious and then some , has 4 in to 1 vance and hines exh.  the cutting out at the high rpm's occured with stock airbox. We have since removed air box put in dyno jet stage 3 done multiple jet combos talked to tech from dyno jet. Told us cb 750 prone to electrical problems. Replaced ignitor switches, replaced coils, took resistance reading from that other coil, forgot the name. A bike mechanic is helping me with this however he is frustrated. Please anyone who can help reply, I do love the bike, don't want to give up.

[Hellbilly429]

What is the charging output of the bike? If it is not getting enough voltage it will not run at higher rpms.
Also these carbs are vacuum driven and are very particular to the stock airbox and need the vacuum to run properly.
Also check the timing if you haven't already, and make sure there is no moisture in there. Check to make sure the advance unit is functioning properly too.

[clarksco]

thank you I will check the timing is correct i will check output voltage. one other thing is the ignition (key switch) when u turn on sometimes you have to jiggle the key to see indicator lights neutral etc.... Thanx again

[Hellbilly429]

Yeah, that Neutral light is just a pain in the ass on these bikes apparently, mine does the same thing and will also go out when I rev the bike up in neutral. Have no Idea why and not a big enough deal to me to care too much about it, but my charging system is currently not working so I am wondering if it isn't that that is causing that problem. Good Luck!