I have a '80 CB650 Custom that I put '74 750 Carbs on (bottle top ones). I got them from Soos a fellow forum member, cb650 guru and modder. He had them running on his '79 650 (His is bored out and has a port joby and he was using the stock air system, I'm using 2 into 1 K&N pods for fitment reasons on an otherwise stock engine). I put them on and synced them (after tuning everything else) and they were all pulling the same. So here's the question(s)
It runs fine while cold but once she warms up the throttle begins to act weird. Sometimes it won't pull past 5500 rpms no matter how much throttle I give. I'm pretty sure my fuel delivery is working (there is an inline filter, and before I get flamed for that, there is no tank filter due to fitment reasons). It starts to bog down and blubber. I'm pretty sure it's way too rich, seeing as how the carbs were meant for a 750. Sometimes it won't want to idle properly either. Neither of these problems are so consistent that I can always replicate them, but I can guarantee they'll happen once it warms up (hopefully that makes sense). Soos suggested that I adjust the needles one notch leaner as well as fiddle with the pickups (advancer?). I removed, cleaned and lubed my advancer and turned it clockwise a wee bit and that seems to have helped some with the idle (before doing this it wouldn't idle while warm unless the idle screw was turned in until it idled at 2500 rpms or more.)
I'm trying to formulate a plan of attack since I'm doubting that adjusting just the needle will fix the problem, though that would be nice. Any suggestions?
Thank
Brandon
