The International CBX Owners Association

Have the 1981 CBX.
Rebuilt the carbs last year and now installed on the bike.
Starts right up but bogs down at the low end. Turn the throttle and it goes....boggggg. If your are gentle you can slowly get it to full killer rpms. It is just that hesitation at the beginning. Have done the bench sync and was hoping to be closer to a ride today but not so.
Any ideas on the low end bog? Thanks, Bud

Sounds like a pilot jet(s) issue.

Who rebuilt the carburetors? If it was you, did you pull the pressed-in idle jets and clean them, and the idle circuit passages?

With all due respect, if it was you that did the carburetors, it’s open-and-shut, that’s your problem.

Not to pile on, but the old adage about rebuilding CBX carbs very likely applies - if you've never done them before, you'll likely have them off and on three times to get them close to right. Even the best mechanics and general carb guys miss or misunderstand a lot of things about these carbs.

Dave

Reviewing your posts from three years ago (it's not realistic that we remember all the details from that long ago without some frame of reference), I see we plowed this ground very well then. There are some pertinent questions that we asked that were never answered. Please review all that and address our concerns from then.

One thing that occurs to me is the ignition advancer. Did you remove and clean it or at least check it for proper operation? Many of these are frozen and would result in what you are seeing if the ignition is not advancing past idle.

Dave

I wanted to ask one more thing.....could the bog down be related to timing? Once it is warm, all you have to do is quickly push the start button and it will idle. Just wanted to know prior to having to do all that work to take the carbs off again. Thanks, Bud in Litchfield Park, AZ.

Yes it could be timing. As Dave said you need to remove the advancer and confirm it is not stuck. If it is, disassemble, clean and lube.

Joe, thanks for that. I will have a look at it later today........I must have the CBX flu. It is 3:00 am yes am and I looking at CBX stuff.
Bud in Litchfield Park

I vote for a faulty accelerator pump circuit
Best,
Phil

First place I would look, Phil.