[RockAZ]

Having gotten significant response from members on my comments in another thread on my observation that my bike has many thousands of miles with the annoying idle hang the first hour of driving I dug into it one more time.

Checked the carb sync - perfect.

Airbox to carbs, carbs to intake runners sealed perfectly (with my blood). Rubber in like new condition.

Plugs, again, perfect combustion indicated.

Fact- after the first 1/2hr to 45 minutes it will not hang the rest of the days ride so why would I muck about with the jets? No complaints from the butt dyno at any rpm

I got the best Motion Pro II cables, lubed with some exotic aerospace oil from a helicopter mechanic when installed.

So - one forum comment stuck out - cables binding. Yep, that was it, two spots on the the return cable were pinched by heavy zip ties that were twisted later for aesthetics. Neither alone would have been enough to pinch the cable inside, but until it got hot enough in those areas to flow that fancy oil the cable would hang.

600 miles and almost three tanks of gas later the hang has not reoccurred. It took a bit of experiment to find the base idle level on that adjuster but I have not touched it since.

Thanks to forum members who insisted the idle hang was not a natural condition for FCR's I went looking to solving an issue I've had for over 20,00 miles.

 

[duc96cr]

If hanging rpm’s is not a mechanical issue or a vacuum leak then it is lean mixture. Richen your idle mixture until it goes away. You may have to play around with the adjustment just to the point where it quits hanging so it doesn’t become to rich when warmed up.

 

[rennsportmotorrad]

I suggest NEVER, NEVER putting wire ties on any cable on your bike --where you can make as big a loop or bend as you can, you do not want any cable on your bike binding in any way--I work mostly on BMW's and from the factory many cables are wire tied and cutting the wire ties normally solves all issues. So on any bike I work on regardless of brand I always make as nice a large radius bend as I can so nothing binds in any way--just a good thing to keep in mind when routing any mechanical cable.

 

[RockAZ]

When I originally put the FCR's on with their new throttle cables I was racing the next day so I had the race bodywork on. Left the cables nice and unbound. So, when I got back from the track I made it "tidy", which created just two tight spots that was just enough to bind until the oil inside the cables warmed up. Would it have gotten this problem without the oil? Probably, but it also could have made it worse without it, so I would have gone looking for a solution years sooner.

*The carbs have been just awesome since I got this sorted out - always been a mild annoyance during the first hour of operation when coming to a stoplight. So glad its fixed!

 

[rennsportmotorrad]

issues like this really suck, but normally it is an easy fix if it is mechanical---lean inside the carbs is another box of gremlins all together lol. But I am happy you found the issue and now have it resolved