Choking at high RPMs

[SmashEmUp]

As described in my first couple posts, I've had a project sitting around my house for about a year now and just recently got it running. I have only taken it for a couple test rides so far because I'm waiting to sort out my wheel/tire situation. First time I cruised around the neighborhood, seemed to be running okay. Second time I shot to the freeway and took it up one exit just to see how it felt at highway speeds. When accelerating it seems to be choking, gasping at high RPMs but seems to run fine otherwise. The bike came with a Kerker aftermarket exhaust and I added some cone filters I picked up off of eBay. Could it be I just need to change out carb jets to account for the intake/exhaust combo? Or is it something else?

Misinform away shinyribs!!

[Lucky 1]

To get the help you need you need to tell the members
what motorcycle you have and all the facts about the engine and carbs.


YEAR???
CB750? 550?
Exhaust Kerker 4 into 1.
Intake type, PODS.
Main jets size.
Idle jets size.
Slide needle clip position.(counting from the top)
Mixture screw turns out.

[SmashEmUp]

Dang, I sure did leave all that out. My bad... 1981 CB750F. Motor was pulled from another bike. Don't much else about the motor itself. I did rebuild the carbs. Found a long, thorough walk through with pictures. I think the car rebuild web pretty well. As I mention in the first post, the bike has a Kerker aftermarket exhaust and a set of eBay cone filters. I'm a noob, so that about all I can think of. Any other info you might need, ask away and I'll tell you what I know! Thanks guys.

[sgtslag]

If the carbs are Keihin Constant Velocity (CV), then get the OEM airbox back on there, with a good filter...  CV carbs are virtually impossible to set up with pod filters, as it screws up the vacuum on the four carbs.  It will drain your patience, and your wallet, trying to make them work on the CV's (the guys on the www.cb750c.com forum have a sticky posting warning members not to even post on the topic -- they consider it a waste of bandwidth, time, etc., and they don't want to spend effort on the topic, period!).  If they are non-CV carbs, it is a different story.

If the engine is cutting out at higher RPM's, only, check the Main Jets for clogging.  There are other possible sources of issues, but these are a good start.  Cheers!

[SmashEmUp]

Thanks for the info sgtslag!