a) wat voor naald zit er in (188 is erg aan de rijke kant !!)
b) kleppen stellen kan je rustig zelf doen, want het is niet moeilijk ...
c) je maakt toch regelmatig het
diafragma van de acceleratorpomp proper ?
d) hoeveel omdraaiingen heeft je gasschroef ?
e)
HET belangrijkste = hoe staat je
acceleratie-pomp ingesteld ? Want vaak staat die op zo'n 3 seconden, en dat is veel te veel. De meesten zetten die op zo'n 1 seconde !
Dit kan je nagaan door de carburator van de motor af te halen (wel even ervoor zorgen dat hij nog vol benzine zit), de uitlaatkant van je weg te houden (anders sproei je in je eigen ogen) , door de carburator heen te kijken en dan met je hand
ineens de gasschuif
volledig opendraaien. Dan zie je onderaan de carburator de benzine wegspuiten, en dan kan je tellen.
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 yields the same result people are paying $80 for the P-38 for. Before you put the carb back on, set the fuel screw (up under the bottom of the carb) at 1.5 to 1.75 turns out. If you have a #45 pilot order a #48. When you get the OCEMN, set the clip on the 4th or 5th notch from top. The fuel screw, needle clip #, and even main jets listed here are only a starting point. If you have an aftermarket pipe or ride in high altitudes you'll need to try different jets for yourself. Just a rule of thumb, your fuel screw has the greatest effect on right-off-idle, your needle clip and taper effect the mid-throttle, and the main's biggest effect is at WFO. Each change can dribble into adjacent ranges.
IMPORTANT: When you pinch closed the fork, focus on bending in the fork side that's butting against the dogleg, this is the only side that matters. To clarify, bend the right fork side TO the left side rather than simply pinching them together, as that may not yield enough movement on the right side fork. What we're trying to change is WHERE this fork stops the dogleg. With the carb off, the bowl primed, and these changes made, you will be able to time a shorter squirt and adjust the fork accordingly.
Staat o.a. op
http://www.x1networks.com/rfsjetting.htm
Jo VdB
Als je denkt aan de afleverbeurt. Je kan je voor stellen dat het afstellen van de acceleratiepomp bij een afleveringsbeurt standaard opgenomen is, toch??