New member with cbx chopper.

[derherr65]

I'm a new member and also new owner of a shiny old 1982 cbx. It's been previously modified to a rifle Supersport fairing, paint reminiscent of a 1966 hertz mustang, 80 series rear tire, a bolt on/off rear seat, and a nearly harley seat height by upper frame modification. I'm a fan, given my inseam.
The next few challenges are a frozen clutch, leaking carb float needles, and a rider backrest/storage solution. No passenger needs on this one.

[steve murdoch icoa #5322]

Welcome to the site, der.
Approximately one million posts on leaking carbs in the Carbs forum.
Frozen clutch can be an easy fix.
viewtopic.php?f=25&t=7568&p=58307&hilit ... tch#p58307
Spotting a Harley in the background so assuming you have some bike knowledge. Feel free to ask if you can't solve your CBX issues.

[daves79x]

Welcome to here! We've chatted on the Facebook page. Someone took a lot of time doing the frame mod. It looks like just about all the electrics/battery have been repositioned. Also looks to be well-done. Your carbs are going to have to come off. They really should have a total rebuild, otherwise you'll be constantly having issues. FYI, the carbs should either have a Stage 3 kit in them for the pods, or greatly up-sized Keihin jets. So what you will find in them is very likely not stock. Proceed with care. If you need to replace the float needles, use only genuine Keihin, and any rubber o-rings with Viton.

Dave

[derherr65]

Frozen clutch can be an easy fix.
viewtopic.php?f=25&t=7568&p=58307&hilit ... tch#p58307
Spotting a Harley in the background...

I have not tried that version of clutch freeing, will give it a shot.
The Harley is Dad's, my other poison is a Triumph Trophy SE.

[derherr65]

It looks like just about all the electrics/battery have been repositioned... Your carbs really should have a total rebuild... either have a Stage 3 kit in them for the pods, or greatly up-sized Keihin jets.

Yes, the wiring looks good, no cheap connectors found yet. The metal work is a touch rough, but I hang out with professional steel workers, so I'm probably overly particular.
Is there a good source for carb theory and operation on these? I'm familiar with edelbrocks and holleys, less so the SU style.

[daves79x]

You really don't need to know much about the 'theory' of these carbs. You just need to know how to rebuild them properly. It's no small task for anyone that has not done them before. Mike Nixon's excellent book is a good starting point. There are dozens of threads here on the subject too. Do yourself a favor and research extensively before buying repair parts and before tearing into them. Most newbies have them off two or three times to get them close to right. You can also send them out if you don't want to mess with them. Good news is that you don't have to tilt the engine to remove the carbs with the pod filters.

Dave

[derherr65]

More of a habit of mine. I like to know the mechanical why and how. Diagnosis is so much easier when you can picture operation in your head.
Edit: Think I found a diagram.

[steve murdoch icoa #5322]

As Dave mentioned the Mike Nixon carb cleaning manual is an excellent resource if you are tackling the job yourself.
https://www.motorcycleproject.com/text/booknook.html

[Larry Zimmer]

Do some photos and careful memory work when you disassemble. The choke mechanism is the 'trickiest' for reassembly. (My experience and opinion.) When synching, remember to start from the inside/middle and work out.

[derherr65]

Battery looks to be good, takes a charge, holds it, and has 310 CCA, not bad for its size. Starter sounds a little slow to me, and slows further after a few cycles. Any starter checks you'd recommend?

[Rick Pope]

Sounds more like a battery issue than the starter. Check resting voltage after a couple attempts.

Another possibility...Check your cams. If someone has worked on the bike and installed the cams per an old service manual, you in effect have two three cylinder engines timed together. This makes it crank hard, and destroys the motor in short order.

[derherr65]

Rick,
I found herdygerdy's post on this item, will check.

Hi Martin,

I am seriously thinking it could be the LH cams are installed 180 degrees out, so you have 2 cylinders actually firing together which turns it from a six cylinder with one cylinder firing at once into a (kind of) three cylinder, but with two cylinders firing at the same time.

Pull the cam cover (but mebbe you are already further in than that?) and check no lobes for any of the three cylinder pairs (ie; 1 & 6, 2 & 5, 3 & 4) are pointing in the same direction.

If your cam positions do NOT look EXACTLY like the photo below, then that will be your problem! In particular, note the positions of the exhaust cam lobes on cyls 1 & 6, and the inlet cam lobes as well.



There is an expensive trap lurking in the camshaft installation instructions of the FSM for the uninformed. The issue becomes you end up with two sets of valves operating at the same time and this doubles the load on the cam chain and valve train, usually resulting in a broken A cam chain, with a tasty side of bent valves tossed in for free, not to mention vibration like it is a Honda C90 running WFO with all the engine mount bolts not even finger tight.

If you had it running and have not yet broken a cam chain, you are one very lucky fellow.

Don't ask me how I know this, been there done that a long time ago in a Galaxy far, far away....(two decades ago, I had my engine in, running and out 9x times before I finally gave up in disgust at my ignorance & incompetence!)

Keep us posted Martin, and we are all here to help solve this mystery.

Cheers...Tony

[NobleHops]

Battery looks to be good, takes a charge, holds it, and has 310 CCA, not bad for its size. Starter sounds a little slow to me, and slows further after a few cycles. Any starter checks you'd recommend?

There are several threads about starter refurb, a very simple job. Do a few searches, all will be revealed .

[derherr65]

Nils did a great write up. Though there are exactly 0 "refurb" ones.
viewtopic.php?f=21&t=8972&p=69691&hilit ... ild#p69691