Trying to do the BK mod, need help


4 replies to this topic
  • e30M3

Posted May 05, 2009 - 08:49 PM

#1

Not sure if I am missing anything here. I have adjusted the timing from over 4 seconds down to about 1.2 (can't go any lower because the bolt I am using is too short).

The stream of gas doesn't hit the slide, it doesn't even look like it comes close so I haven't played with that setting.

The main questions I have are: do I need to get the timing closer so the spray comes closer to the slide? If so, does it make a difference if I set the timing before or after the duration?

Also, i am stabbing the throttle and holding it wide open-I assume this is the preferred method in setting the timing?

the bike is an '02 426...

  • GCannon

Posted May 06, 2009 - 10:41 AM

#2

Yes You want the the squirt to just miss the slide, this will initiate the squirt sooner.

I am running about a .5 second squirt duration and then you need to rejet accordingly

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  • grayracer513

Posted May 06, 2009 - 10:58 AM

#3

Also, i am stabbing the throttle and holding it wide open-I assume this is the preferred method in setting the timing?

Since you don't (or shouldn't) ever really ride like that, it isn't really representative of what goes on in "real world" situations. Open the throttle in a realistically quick fashion. It should not matter how rapidly it's opened, the squirt should clear the slide in either case.

Note that the squirt timing and squirt duration are two different things, adjusted somewhat independently of each other.

  • e30M3

Posted May 06, 2009 - 06:59 PM

#4

Since you don't (or shouldn't) ever really ride like that, it isn't really representative of what goes on in "real world" situations. Open the throttle in a realistically quick fashion. It should not matter how rapidly it's opened, the squirt should clear the slide in either case.

Note that the squirt timing and squirt duration are two different things, adjusted somewhat independently of each other.


I am pretty slow so I don't stab the throttle too much:thumbsup:

Speaking of jetting, any suggestions on what changes (ie. 2 richer on the pilot, etc..). I imagine I only need to be concerned with the low speed circuits and not the main? I have never been great with carburaters (I can't even spell the word)...

  • grayracer513

Posted May 06, 2009 - 07:35 PM

#5

I have never been great with carburaters (I can't even spell the word)...

Carburetors.

Jetting used by others:
http://www.thumperta...ad.php?t=694921
(scroll down to the link for the 426)

More good reading:

Adjusting the pilot
http://www.thumperfa.../jetting.htm#PJ

How to tell if the pilot is the right size
http://www.thumperta...ad.php?t=327405

Jetting without a dyno, etc.
http://www.thumperta...699#post2881699





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