Dave F Mod: tuning issues

[MRDRcycle]

"Before installing the 169 series needle jet, the spray bar (shield) must be cut down or the mid range circuit will operate too late and screw up everything. With a pair of venier calipers set to 2mm, use the id measuring portion and mark off a line that is 2mm from the base of the needle that would be flush with the carb bore. Hold the needle jet in a vise (gently) and position the scribe mark in such a way as to use the sides of the jaws as a guide for the blade. Using just a fine (32 teeth per inch) hacksaw blade, cut just barely away from the line, leaving enough to trim the length with a fine file."

Years ago when I installed the Dave F mod I did not trim down the needle jet. I just found this information which wasn't part of the original instructions that I used. I haven't been running anything other than Dave F modded carbs, and have had tuning problems since I've owned the bike. I've gone through everything: timing, compression, new coils, leak down test, new batteries, etc..

I was thinking about buying brand new carbs, but figured I'd ask about this first.

[SUPERTUNE]

All depends how modified the bike is, and have seen even the JL's run richer in the mid than Spec 2 pipes.
On my street ported setups.
I cut them 1.7mm or 2 mm off the top, not from the bottom.
Need more info on your setup...Engine modified?
RD350? RD400? Did you go with a Y boot? K&N or Uni? Are they over oiled?

Chuck

[MRDRcycle]

Thanks Chuck! I've been out of town and sorry for the late reply. I have a 73' RD350, over bored .025?? ( I haven't looked in a long time), 28mm carbs, stock manifolds, Y-boot and Uni, dyna S ignition (set at 2.0mm BTDC), pipeline expansion chambers.

I just cleaned and oiled my uni filter. I was pretty liberal with the uni filter oil spray can. Hopefully I didn't go overboard.