HondaCB650

Carb synch didn't help either, even though it evened it out a lot and it does a bit better all the way up to the miss. But it revs all the way up when it's in neutral, so this IS fuel, isn't it? Now I'm going to try to plumb up the stock tank and see if there's any remote possibility that the CX500 ...

The needle jets appear to be stock; no washers, grooves or clips.

The bike will rev all the way to red-line at idle. The missing is under load.


Off to do a carb synch....

Removing the air box cover did not change the missing/bogging at 5k rpms.

Thank you, excellent information. I do not recall the needles being shim-able, and I had every single thing apart. I don't remember any clips, or any damage or wear on the needles. Still, if I end up yanking the carbs again, that will be the first thing I look at.

Worth a try....

Stock paper filter I think. I don't see a brand name on it.

So with the 900, you could quickly accelerate through the gears and rev the engine normally, but under load at higher RPMs it would bog down? Before I try the complex stuff, I'm gonna try more simple/easy stuff: route in a longer fuel line and try a larger filter. I don't think that's the problem, b...

Just rebuilt the carbs on the 1982 Nighthawk 650 and now the idle is good, but it bogs down at about 4500 to 6k rpm. I can't get the bike to go more than 55 mph. When this happened to my 1979 CX500, it was related to the high-speed coils inside the engine. There's an aftermarket CDI that fixes the p...

Woot! We have a clean idle!

Crisp, responsive, adjustable, rideable.

Except now it's bogging down at 4.6 to 6 RPMs. Can't get it to go faster than 55.

Is there a high-speed coil on this bike?

What is the word for the part of the air box that holds the boots, but not the air filter? Plenum? I removed the (Plenum?) and the four airbox boots, and also the boot that goes to the air filter part of the air box. All the air box boots are plenty supple enough that they should be able to run. The...

OK this is also what I need to hear, thanks. I did not remove the pressed-in jets, but each carb went through the ulstrasonic a bajillion times until no funk was coming out of anywhere. I swear by that thing. I don't even try to remove pressed-in jets anymore. I'm not sure if I can remove the air bo...

OK thanks, this is all stuff I will have to check. These carbs DID have a sticking throttle plate from where someone else got heavy-handed with them, and I had to do a LOT of work to get them to move smoothly again. Could they have become out of alignment on install? Can I pull the air box boots and...

If you think that will help, I will synch them. I carefully bench-synched them before installation. That seems to be something I generally get right the first time, but hey, I might have messed up.

HOWEVER...if I can't adjust the idle at all, how can I possibly synch them?

I'm not really sure what to do now. I know that a hanging idle is usually an intake leak, but I'm not getting an idle change when I spray WD40 around the boots. the bike starts well enough but with choke off, won't idle less than 2.5k. The adjuster knob is turned out all the way. I moved the idle mi...

By sewing, I mean making custom seat covers for motorcycle and ATV seats. I also do seat shaping, building up or cutting down the foam to make the seats more comfortable for individual riders, and repairing damage to foam. The ebay seller, who is the same guy on the 1100 forums, confirms that the re...