Stotteren van motor met Keihin FCR carb met acceleratiepomp
Geplaatst: vr okt 04, 2002 22:05
Hallo,
hier DE oplossing voor Yamaha's en KTM'ekkes die last hebben van stotteren bij het abrupt opendraaien van de gashandle. (Bij KTM is het simpel, die hebben daar allemaal last van....)
Het komt immers opdat de duurtijd van de inspuiting door de acceleratiepomp TE groot is.
Lees onderstaande en pas het toe. Ik heb het al zo'n jaar geleden toegepast, tot GROTE voldoening.
Zie ook http://www.x1networks.com/rfs.htm
Next, the tricky part of the carb modification, the accelerator pump. Pull the carburetor out (it helps to unbolt the two lower subframe bolts and swing the subframe up), re-prime the bowl by attaching the fuel line and opening/closing the petcock, detach, then point the carburetor intake manifold end AWAY from you, the kids, the fireplace, etc and twist the bellcrank (what the cables turn). Turn and hold, and either you'll see the accelerator pump squirt fuel halfway across the garage, or up your nose and down your shirt, depending on the orientation of the carb (speaking from experience). It should flow for a good 3+ seconds, which is TOO MUCH FUEL. Now, put the carb down on it's choke knob side so the bellcrank is facing up. Note the metal linkage running from the bellcrank to the black plastic dogleg, actuating a plunger going into the bottom of the carb, that's the accelerator pump. Next, note where the black dogleg stops against a metal fork (arrow).
That fork can be carefully pinched closed. This limits the amount of travel the accelerator pump will have, and will shorten the squirt time. We want our squirt time right around 1 second, but I think +/- 20% is close enough. I started by pinching this fork stop all the way closed and resulted in no squirt (be sure to re-prime your bowl after each squirt). I then took a small flat-blade screwdriver to the pinched gap and started opening it back up little by little, then timing the squirt until I got 1 second. This will yield noticeably better behavior when you snap the throttle open. The bike won't be so prone to bogging or be so soft when you want to pop the front end over something. No, this is not precision engineering, but it really works !
hier DE oplossing voor Yamaha's en KTM'ekkes die last hebben van stotteren bij het abrupt opendraaien van de gashandle. (Bij KTM is het simpel, die hebben daar allemaal last van....)
Het komt immers opdat de duurtijd van de inspuiting door de acceleratiepomp TE groot is.
Lees onderstaande en pas het toe. Ik heb het al zo'n jaar geleden toegepast, tot GROTE voldoening.
Zie ook http://www.x1networks.com/rfs.htm
Next, the tricky part of the carb modification, the accelerator pump. Pull the carburetor out (it helps to unbolt the two lower subframe bolts and swing the subframe up), re-prime the bowl by attaching the fuel line and opening/closing the petcock, detach, then point the carburetor intake manifold end AWAY from you, the kids, the fireplace, etc and twist the bellcrank (what the cables turn). Turn and hold, and either you'll see the accelerator pump squirt fuel halfway across the garage, or up your nose and down your shirt, depending on the orientation of the carb (speaking from experience). It should flow for a good 3+ seconds, which is TOO MUCH FUEL. Now, put the carb down on it's choke knob side so the bellcrank is facing up. Note the metal linkage running from the bellcrank to the black plastic dogleg, actuating a plunger going into the bottom of the carb, that's the accelerator pump. Next, note where the black dogleg stops against a metal fork (arrow).
That fork can be carefully pinched closed. This limits the amount of travel the accelerator pump will have, and will shorten the squirt time. We want our squirt time right around 1 second, but I think +/- 20% is close enough. I started by pinching this fork stop all the way closed and resulted in no squirt (be sure to re-prime your bowl after each squirt). I then took a small flat-blade screwdriver to the pinched gap and started opening it back up little by little, then timing the squirt until I got 1 second. This will yield noticeably better behavior when you snap the throttle open. The bike won't be so prone to bogging or be so soft when you want to pop the front end over something. No, this is not precision engineering, but it really works !