If / when I'm cruising down the road... I will definitely have a larger than normal grin... (and a small fire extinguisher in the under passenger seat storage.

 

The plate sticker is pretty tell tale.




First time in 16 years it's seen the sun. It runs *amazingly*... just like I remember 16 years ago. So difficult to not just continue to roll the throttle on... rush of power.. gear whine... Glorious! I'll have to do some sole searching as to why I decided to stop riding it.

(iPhone camera doesn't do it justice. It's deep purple / light lime green / black. I tried color correcting in photoshop.)
I was very careful to put all removed hardware in zip lock bags, however, I still managed to misplace one fairing large flange bolt. Only issue I noticed so far was the rear brake seems a bit ineffective (I replace the brake line with steel braided.) Perhaps it needs bleeding again.

Here's one other addition I thought prudent considering the nature of the work I did to get it running:

One of the few sport bikes I know of that has enough room for a mini extinguisher. I had visions of a blown fuel line causing a fire and no ability to do anything about it except watch it burn. It actually fits really well, and it and the tool kit are still under the placarded weight for the cargo area.

 

Glad we got to see the finished product, all you need to do now is enjoy

 

Very sharp bike indeed. It looks different and much better than the previous posts.

 

Did a 100 mile ride with 25 other bikes on Saturday (mostly cruisers / Harleys). The CBR definitely stood out in that crowd (and got its fair share of attention.)

There seems to be one other little engine gremlin lurking beneath the fairing:
Initially, after all the pain of getting it running properly, it ran silky smooth... idle to high rpms. When I came to a stop 25 or so miles into a ride, it felt like it was missing and I had to really feather the clutch to get it going. Above 4k or so, it felt fine (no noticeable loss of power... it pulled hard.) Aborted the trip and returned home. I bought an optical thermometer and measured the header pipe temps to see if I could ID the cylinder(s) that was dropping. At idle, they were all about 450F except for #2 which was about 358F.

I pulled the #2 plug (and #1 to compare) and #2 was slightly wet around the threads (it also seemed *very* easy to remove, like I hadn't tightened it enough.) I removed some of the anti-seize compound from the threads (thinking I used too much and it was leaking around the threads), and also swapped it with plug #1, then reinstalled both. Did a 25 mile test ride, and it behaved perfectly. Problem solved... or so I thought.

Two weeks later, I was on my way to the starting point for the 100 mile Poker Run ride and I noticed it was dropping again when I came to a stop. Reaching my destination, I pulled the side fairings and checked #1 and #2 plugs, which both looked pretty good (and both seemed tight).

So my symptoms are:
- Sometimes runs perfectly until 25 or so miles, then starts dropping/running rough at low RPMs. Sometimes, it starts dropping immediately after a cold start.
- #2 consistently reads ~100F below 1,3 & 4 at idle (when it is dropping a cylinder/running rough)
- Problem did not follow the spark plug with regard to header pipe temperature (swapped plugs 1 & 2), #2 remained low reading
- Doesn't seem to impact speeds above 4k RPM... still pulls hard, runs smooth above ~4k.

Does this sound like an electrical issue? Would replacing the coil feeding #2 be a place to start? (I know the carbs are absolutely spotless inside, as detailed in the previous dozen post pages.) Can't think of a fuel reason that a cylinder would be missing, and be intermittent.

Thanks!

 

I would tend to think that you are on the right track with the coll.

 

I am currently having the same issue with my 97! Number 2 is running consistently 100-150 deg below the others for more than a month. I have just completed a ultrasonic cleaning of all carbs individually and just synced them. When trying to complete an Idol drop test I get no response from the #2 pilot adjustment. lightly seated to almost falling there is no change in RPM.

I tested both the coils and got the same readings on the primary and secondary sides. Getting the same voltage to each coil as well. Currently I cannot check peak voltage as do not have a PVA as referenced in the manual. I am close to my wits end about this issue.

 

Hmm, that is interesting! I've tried to go down the line of symptoms and rule out possible causes (for me):
- It's intermittent - sometimes happens immediately on a cold start, other times runs great for 20-30 miles, then occurs
I cannot think of a carburation or fuel reason for this. One thought was mixture screw moving. But the fact that I've shut it down while it's having the issue, and the next day, the issue is gone (for a while) rules that out.
- Another thought was vacuum leak, but same as above, it's unlikely it could intermittently fix itself.
- Electrical - My symptoms are very characteristic of an electrical issue (which can be notoriously intermittent).

For you:
Does #2 plug look noticeably different? Try swapping or replacing the plug? Plug wires in good condition?
What are the operating characteristics? Does it stumble at idle, but still pull hard above a certain RPM? Or noticeable at all RPMS?
After carb cleaning, did you blow air or carb cleaner through each orifice to ensure air or cleaner came out 'somewhere else'? It sort of sounds like you still have a clogged passage (which does seem unlikely after ultrasonic cleaning). But after you've ruled out the possible... time to look at the improbable.
I assume you inspected the vacuum diaphragms carefully for holes or tears when you had the carbs apart. A vacuum leak would obviously make getting things in spec impossible.

If you still suspect fuel issue, the thing that finally illuminated my issue was a float bowl level test. (Clear tubes connected to the drain nipples of each carb.... I think I posted a video on here somewhere.) That instantly showed my fuel problem and lead to my solution (which was, don't cover the air vents needed to equalize the air pressure in the float chambers!)

For both of us:
It's obvious we're getting fuel and spark to #2. We're just getting the wrong mixture, or fewer or weak spark. If problem is consistent, it doesn't rule out either mixture or electrical (need to devise additional tests to rule out one cause or the other). If intermittent, electrical is highly suspect. Electrical can be:
- Plug
- Plug wire
- Coil
- ECU
- ECU wire harness (to coils)
(Left out voltage reg / charging system. Lots of other things would not be working if those had issues).

I have not tried swapping coils yet to see if my problem remains with #2 or moves.

As others have encouraged me at my many stops at wit's end: stick with it. I know the following falls under the 'no $hiT' category, but I had to occasionally remind myself that it's a mechanical device. Physics, not magic applies. If you can't ID what it is, then determine what it isn't. Keep finding or figuring out tests to provide little bits of evidence one way or another. As frustrating as it is, the light bulb will eventually go on. You'll get it.

 

Yep, will always stick with it. I’m too cheap not to, though my wife gets frustrated with the time I spend trying to figure things out. Think she would just rather me pay for someone to do it so I can do the other things she doesn’t want to do.

My issue may have been going on longer than a month but I didn’t notice it until a weird weather Wednesday here in the Hills. Was running fine when I left work but half way home, wanted to die at idle and really rough like I lost a cylinder. But under throttle would run fine.

After this his last carb cleaning she was running smooth for the carb sync. Had a nice little roar when blippin’ the throttle.

Just weird to me me how everything seems so smooth with all the power that I need when needed but number 2 running much cooler than the others.

Plugs are brand new as of a month ago and spark evenly on spark test (even when I swap #2 with #1). The old plugs looked normal when switched and even ohm tested within specs.

Trying to research more info to help isolate the issue. Think next step will be to switch coils to see if it moves with the coil.