First off glad to be back. Been unable to log on???
Been riding my X between rainy days and fixing oil leaks and misc. things.
Bike will rev to about 7000 maybe a little more and lays down? ?pulled carbs recleaned jets and passages, . Opened idle mixture scews to 2 1/4 turn. Idles better now. :) but still wont rev up . checked timing right on money. These are 82 carbs. what is the stock main jet size . And how much bigger should I go . Bike has K&N filter, bub 6into 2 with super trap mufflers . six disks each. Tried my winning 6/1. it was even worse. plugs are a light tan???go figure.
I was wondering where you got off to. Using the search function I found this. I thought there were primary and secondary jets and (both) have to be working together to make it run throughout the rev range. This list is pretty complete. Good luck!
"When I asked Mike Nixon for advice, he gave me a list of possibilities. I don't think he would mind if I passed it on to you."
* Idle circuits not totally clear (very difficult to do, even for a pro)
* Idle mixture screws put in wrong (order of o-ring and washer primarily)
* Carb synch
* Tight valves
* Mixed up primary and secondary main jets
* Individual air filters
* Vacuum leaks at manifolds
* Vacuum leaks at throttle shafts
* Ignition timing anomalies
Does it pull hard to 7000 ? When you say "lay down" do you mean goes flat or cuts out ? Sorry us Brits don't know of that term. Well this Brit doesn't...
not hard as I remember but strong., Not cutting out. Can leave throttle open just wont rev any higher. Tried to use choke to richen . but didnt work either. Going to buy a exhaust bung today. and try to check with a AFR meter.
Check the airbox to make sure critters haven't established residency in there. A mouse nest / leftover food will severly restrict airflow at higher RPM's.
When I bought a CB700SC it experienced the same symptoms. Ran perfect at lower RPM's, wouldn't rev out though. Just stopped revving up at whatever RPM (high) it was. Really stumped me until I found the air snorkel on top of the air box was reversed (PO had it facing forward instead of back) which cut the opening size for the airbox by about 1/3. Turned the snorkel back around and bingo, she revved perfectly.
Hi all , just tried a free rev . motor goes to about 7300rpm ?? Motor starts cutting out.Acts like it has a limiter on it?? playing with choke has no effect. Will pick up some starting fluid in morn. try squriting it in air box.
Thanks for all the replies
alimey4u2 wrote:If the motor doesn't rev in neutral I wonder about the spark advancer..???
Sticking vacuum slides ??
Failing that, something stuck in the exhaust ??
If you have had the carbs apart, not getting the carb tops indexed correctly can cause the slides to stick and not move all the way up during acceleration and keep it from reving up. You need to make sure the slides move freely before installing them on the bike.
If i use a air gun in the carb slides move with very little presure.
If it had points ,runs like the dwells off??
Will try to check the advancer this evening. thanks guys
Tried spraying starting fluid in the air box while reving motor . Thinking extra fuel would help.nope it didnt. made it worse.
Coils are new Dyna units.
Starting think its Ign.??
Been unable to log on??? 
?pulled carbs recleaned jets and passages, . Opened idle mixture scews to 2 1/4 turn. Idles better now. :) but still wont rev up . checked timing right on money. These are 82 carbs. what is the stock main jet size . And how much bigger should I go . Bike has K&N filter, bub 6into 2 with super trap mufflers . six disks each. Tried my winning 6/1. it was even worse. plugs are a light tan???go figure.
