Throttle pickup from idle

I have a 1996 Honda CBR1000F. I am very happy with it, except for one
little annoyance: When I want to add power after having it completely
closed, it is very difficult to avoid a jerk just as the throttle
opens.

Earlier, it was impossible to avoid the jerk. Since then, I have
replaced the drive chain, adjusted the valves, synched the carbs and
lubed and adjusted the throttle cables and throttle grip. It helped
somewhat, but it is till not right. I have to be extremely careful if
I want to avoid the jerky transition.

Running at a very high gear more or less eliminates the problem, but
that is just masking the symptom, not solving the problem.

The engine runs, as far is I can tell, perfectly otherwise.

This can't be normal? How to I troubleshoot this?

 

My last VFR did that when I bought it. I think I just learned to ride
around it as I didn't do anything to cure it beyond replacing the worn
out chain & sprockets - the bike had sat in a barn for 5 years before I
bought it.

What you might want to try is replacing the cush drive rubbers in the
rear sprocket carrier. I intended to do that with the VFR but there was
always something more useful to spend the money on - usually petrol

 

What you describe is fairly common on modern bikes with CV carbs. The
short story is that the idle mixture is set very lean from the factory
in order to meet smog standards. When you open the throttle, the
mixture momentarily leans out even more, until the slide moves enough
to properly enrichen the mixture. The engine catches suddenly and you
get a sudden burst of power.

The simple fix is to adjust the idle mixture screws for best idle,
rather than best emissions. Turn each of the mixture screws out
(counterclockwise) 1/4 of a turn at a time. The idle speed will pick
up initially, then stop increasing as the mixture reaches proper air-
to-fuel ratio. You might want to then try turning each screw back in
1/4 of a turn at a time until the idle speed drops off, then open each
back up by 1/4 turn.

This should help. Good luck.

 

Yes, I am.

Yes, even cars have plenty of slop. The point is that if the rider (or
driver) is able to take out the slack gently, the jerk will be small,
maybe even not noticeable.

I'll see what I can find. If that does not solve the problem, I'll
take the carbs apart and clean them manually.

It seems I have to remove the carbs to get to them. They seem to be
located on the underside of the carb. Can it be that stupidly made?

I just remembered: The idle speed knob is very sensitive. It is
difficult to get the right idle speed. Even the slightest twist will
be too much one way or the other. Of course, the rubber connection
between the knob and the actual screw does not help.

I will. It may be spring before I get to it, though. Winter is coming,
and we haven't even had a summer yet.

Thanks to you and everyone else for your suggestions.

 

***************************************
I have one of these for 4-stroke carb adjustment for atvs and
motorcycles:
http://www.motionpro.com/motorcycle/tools/pilot_screw_adjusting_tool/
I've found it to be extremely handy, No more burned fingers, and no
more removing the carbs from atvs, just to adjust the idle fuel screw.
It might help you.

Good Riding and Good Wrenching to You!



Wudsracer/Jim Cook
Smackover Racing
'06 Gas Gas DE300
'82 Husqvarna XC250
Team LAGNAF