I bought my 1990 CBR1000F on October 4th, 1990 from Hartley Motors in Wasilla, AK. There is a bit of a story about how that came to be, but probably only of interest to me. I brought it, along with an '87 GSX-R1100 (gone and still missed) and the faithful 750F to Idaho in 1993. It had been my touring bike until a few years ago, along with the R100GS-PD. It has over 73,000 miles on it, mostly touring. It has been all over the western U.S. and as far east as Louisiana, and is featured quite a bit in the interesting roads thread. But it hasn't been on any long rides since 2017 when a series of mishaps befell it. No crashes, but problems that became show-stoppers that I had to work through. It has been sitting for two years because it developed a hanging idle between 2500-3000 RPM. Speed in sixth gear at that RPM is 45-50 mph. Made it interesting going into corners on tight roads, for sure. CV carbs made it likely a vacuum leak was the culprit because nothing was sticking. So last week I got into the carbs to see what I could discover.
To my eye, the second generation CBR1000F in this paint scheme is one of Honda's prettiest bikes, I think second only to the RC30. But it is homely with its clothes off -
This bike isn't the worst I've seen to get to the carbs on a perimeter framed bike. I've had them off a few times before, so I had practice -
They were surprising clean on the outside, a benefit of living inside a plastic cocoon, I reckon.
It got a little fiddly getting to this point, as well as putting them back together -
First thing I found was all the 33 year old o-rings were hard and crumbly. To be expected and what I hoped would be the problem -
The problem with this old bike is that so many parts are no longer available from Honda. And the bad thing is that many of those parts are rubber and plastic. They sold the t-joints as a set with the o-rings, and are not included in their ridiculously expensive "rebuild kit". I was able to find o-rings that were close enough in an o-ring kt I had on hand, but here is what may be the ultimate showstopper for the bike - the vacuum chamber diaphragms. They have been NLA for years. These don't have any holes or cracks, but it is just a matter of time. They have shrunk a little bit, are wrinkly, and seem a little stiff. I had no choice but to glue the edges to the top of the carb bodies with a thin layer of Permetex Gray to hold them in place until the top plates were reinstalled. And hope for the best.
Got them back together and back in the bike. The next thing to do was get my extremely hazardous mercury carb synch tool out that has killed me many times. The bike started and idled horribly but was soon running smoothly, just like I remembered from the good old days.
I could tell right away, even before the carbs were synched, that it was going to be OK. Sure enough, no more hanging idle. I took it for some rides the last few days and it is back to its brilliant old self. It is good to have it back. There have been a lot of memories and adventures associated with this bike -
