High tick-over when warm

[russellak007]

I just got my CBX1000Z on the road in Hong Kong after importing it from South Africa. It's going fine, but when warm, the tickover goes up from the usual ~1,000 to more like 2,500-3,000. There doesn't appear to be any issues with the carb rubbers (and surely that would cause an issue either hot or cold) and interestingly, my good friend who has one of the other two CBX1000's in HK has exactly the same problem. Any ideas where to start looking?

Also, bizarrely, the tacho appears to read low - like less than 3,000rpm at 100kph. It seems to work fine but it feels like the bike is revving higher than it shows (also the impression of my mate). Chain and sprockets are standard. Anyone encountered this before?

Keith

[daves79x]

Keith - Your problem is likely carbs way out of sync, but could be plugged idle jets that a PO compensated for. Less likely, but easiest to check, is the advancer. It can get sticky and hang up, causing a high idle. But it's most likely the carbs, and be prepared for some serious work on them if a gauge sync does not settle them down nicely. Also, check that your choke cable is installed correctly (rubber boot at the bars - not at the carbs), and that it goes completely slack when off, or else it will hold up your idle.

Dave

[russellak007]

Thanks Dave - I'll have a look at these points for sure. Can I ask what the advancer is? Is that the auto-advance on the ignition system?

[daves79x]

Yes, the mechanical ignition advancer hiding behind the pulse unit on the clutch cover. You will have to statically re-time the pulse units when you’re done. That should be at least checked for sure, but you must get a set of vacuum gauges on the carbs to see where you are.

Dave