Topic: Jetting Question/Sticky throttle

[6685]

I have a 77 cb750k with K&N Pods and Carpy's 4 into 1 exhaust.  I changed the main jets from stock 115s to 130s.  The carbs are in sync, clean, and the intakes have no cracks.  She idles fine and pulls away good, but when I acclerate hard on the throttle she starts to sputter. Do you think I need bigger main jets?
Also, when I gas the throttle it takes awhile for it to return to idle.  The throttle seems to stick and hang at the higher idle.  New throttle cables are on the bike.  I am totally lost with this.  Please help.  Thanks.

[Mayor08]

6685-

I had a similar problem with my bike after the carbs were rebuilt in my case the sticking was as I applied throttle.  It would "stick" but when enough throttle input was applied the carbs would suddenly let go.

I thought it was a cable issue but mine were new.  I pulled the carbs to change the needle clip height and discovered that one of the needles was machined incorrectly and was too wide and catching.  It was luck that I noticed it at all but I took a file to it and took off the small ridge that had formed and no more sticking throttle.  It may not be your problem but something to look at.

[domer]

Maybe a float height issue?

[Steve_K]

If you have both throttle cables on and adjusted correctly, you should be able to close the throttle by turning it back to idle.  That should tell you if the cable is sticky.  Lube the cables and clean and lube the throttle tube if it does not snap back.  Check cable routing with tank on and off.  If it still seems to hang,  carbs may need adjusting.  Possible carb balancing, intake leaks or idle mixture adjustments.  It's can be slow going when you want to ride
Steve

[Scott S]

 I'm having the same issue on my CB500. The carbs have been apart at least three times now. They've been vacuumed synched and I can't find any vacuum leaks anywhere. Brand new Honda cable.
 I was hoping that I would find something with the timing, advance weights/springs, etc., but I just had an electronic ignition installed and it's still hanging up. Goes back down when you blip the throttle.
 
 I'm thinking about taking a clue from Mayor08 and checking the slides and needles again for anything that could be sticking.

[Scott S]

 Thinking out loud here.....When mine sticks/hangs, the throttle is against the idle stop screw. If something mechanical in the carbs was sticking, there would be a gap, right?
  I'm still not ruling out an advance problem.