Bob@(some hp site) was asking about slow jets, and I lost his addr. Anyhow, I stole this out of the Oct (94?) Thunder Press' Motohead Memo, by Kip Woodring (reformating and typos mine): Recently updated to include info dug up by Don Crafts from WorldWide Glide, and some info I got out of H&M Harley Davidson's catalog. This list only applies to 88 and later Sportsters and 90 and later Big Twins with the Keihin CV carb. This is not for older style Keihin butterfly style carbs. Jet Needle (mid-range) in decending order Rich->Lean 27175-90 N72R Rich 27176-90 (CA Only) | 27178-90 N72S | 27179-90 (CA Only) | 27184-92 N86F | 27186-92 N86E | 27280-92 (CA Only) Lean Pilot Jet (low or slow speed) 27165-90 48 Rich 27170-89 45 | 27171-89 42 | 27281-92 40 | 27117-88 35 Lean Main Jet (high speed) 27105-88 200 Rich 27185-90 185 | 27114-88 180 | 27090-89 175 | 27115-88 170 | 27116-88 165 | 27152-89 160 | 27154-89 155 Lean Kip mentions that this was a tough list to compile, as The Company provides only part numbers, no sizes or any other info for this stuff. Thanks Kip! For CA folks, Thunder Press is free at motoshops everywhere. Non-CA subscriptions can be had. Contact Thunder Press via email at: firstname.lastname@example.org.