Why don't you rephrase the question using rpm and gear position or percent
of full load. 95 to 120 mph is pretty meaningless as it has nothing to do
with airflow. next do yourself a favor and buy an A/F ratio meter they are
$350 for a wide band with sensor.. Yes if the ignition is ok at WOT it
probably has enough energy but that says nothing about the advace curve. BTW
the engine will stumble if it is too rich as well. Generally too lean it
will feel like it is nosing over. Find out if it is RPM related or load
realted there are probably many ways to get to 120 mph..
> -----Original Message-----
> From: firstname.lastname@example.org
> [mailto:email@example.com]On Behalf Of atrav
> Sent: Sunday, May 01, 2005 9:02 PM
> To: LSR list
> Subject: Tuning CV motorcycle carbs
> With a constant velocity carb, the Keihin motorcycle type, how do
> you know whether to raise the
> needle or increase main jet size?
> What's happening is that between like 95 mph and 120 mph I have
> quite a stumble at part throttle.
> When I go WOT, it's fine. If I close the throttle, it'll speed up
> for a second. So, I think at
> partial throttle at that speed it's running too lean.
> Also, if this were ignition weakness, wouldn't it get worse at WOT?