Hi, winter suddenly came strolling along and the bike now sits in the basement.
It's undergoing a long needed maintenance, like fluid and filter changes.
A new chain and sprockets will also be installed before spring.

It's a -97 with 60-something thousand km on the clock (~40 000 miles).

At the end of the season it seemed like not all cylinders were firing when cold and at low rpm's.
In addition it seemed a little sluggish, and it felt like it took longer to get to 125Mph than last year.

I've had the firing problem before on another bike, and found a clogged idle jet that prevented one of the cylinders from getting fuel at rpm's less than say 3000.
When I started picking the CBR apart, however, I found the dirtiest airfilter I've ever seen. It had flies and wasps and pebbles and whatnot (cause of the poor high-speed performance?).
I'm expecting performance gain just from changing the filter, but I'd like to check up on the carbs as well.
In the PDF manual I can't seem to find the "idle jet", is the correct name "slow jet"?
(it may seem natural for you, but English is really not my first language, so I struggle sometimes)
I had the carbs off a couple years ago, but only to have a look and get to know the bike (I bought it as a project).

Also, would it be wise to check valve clearances?
Do I need any special tools (torque wrench? if so, which type?)?

Please tell me that valves don't need checking, it would make my life easier
I did read the pictorial from the guy who did his own valves, but I'm still a little scared.
Pictorial was great, though!

Long post, I apologize [sm=love.gif]

Thanks in advance,
Gunnar

 

It's my understanding that the Slow Jet and the Idle Jet are one in the same (someone correct me here). Most of your performance issues are most likely related to carbs that need a good cleaning and synchronizing. As for checking the valve clearance, that's pretty straight forward. You just need the gasket for the valve cover, some feeler guages and instructions for the procedure. The tougher part is what do you do if after checking you find out that they're out of spec.That's whenyou have a decision to make.

Hope this helps.

 

If you think that one of your cylinders is not firing, you can always check the header pipes with an infrared thermometer.

 

Thanks to both of you[sm=icon_cheers.gif]
Never thought of using an infrared thermometer before, that would be a great help in finding the right one.

As for valves, I think I'll check them due to the high mileage on the bike.
If they're off, I'll just have to do the job, I guess.
We have long winters, so time is on my side. And I sure as heck won't take it to a dealer.
Took one of my previous bikes to a dealer once, and I've regretted it ever since. The bike was not the same when I got it back (and not in a good way).
And on top of it all I got a lecture in how bad my bike was (of course it wasn't).

Thanks again,
Gunnar