Jet physical sizes

[Corndog]

Hi all,

I ordered some new mains and slow jets for the valk. 107.5 mains and 38 slows (oem sizes in there currently, going off of the recommendation for a K&N filter + cobra pipes)

These are not keihin jets, as they are difficult/expensize to track down in Canada. Instead I went with an aftermarket replacement made by (or sold by, at least) EBC. The slows are an exact match, but the mains are 1mm longer in the head. The threading and diameters are all correct. OEM is 8mm long while the ebc ones are 9mm. Should this pose an issue?

[98valk]

unless u are doing air box mods 107.5 will be too large.

there are tall and short main jets, I would use same length as oem so not to worry about any clearance issues.

[Corndog]

Damn. I was going by this as a guide: http://www.valkyrieriders.com/shoptalk/jetting.htm

I've seen numbers all over the map that people use for mains + mixture settings.

[98valk]

http://www.valkyrieforum.com/forum/tech_archive.cgi?read=969520

This was posted by J. Orr, 3/27/1998, on the GWRRA BBS, valkyrie section.
The following mods were done by Marc the owner of Factory Pro of a valkyrie that had cobra 6x6 pipes.
K&N filter (w/o prefilter)
Air box mod (remove plastic welded baffle)
38 pilot jet
3.5 turns idle mixture screw
front needles set on #3
mid and rear needles set on #2
115 main jets all carbs
this picked up 5 hp over the base run with the cobras.

this HP is still down from the stock pipes or almost the same.

factorypro recommends only going up one size on mj on rear 4 cyl and going down 1 size front 2 cyl, when using after market exhaust and no air box mods.

many over the yrs have only needed to use adjustable needles and open up the mixture screws 1/2 to 1 turn with just cobras installed.

[98valk]

found the factorypro carb install kit instructions I have.

two brothers 6x6 similar to your cobras, k-n filter, no pre-filter and no airbox lid baffles, 105 MJ, needle position 3, 38 PJ.

cobra needles are richer than factory pro needles. cobra jet kit only changed out needles and I think slide springs. no mj or pj.

[Corndog]

Thanks for the info CA, much appreciated! The longer jet didn't seem to cause an issue. That jet is normally totally submerged in fuel, and it cleared the float bowl fine so so harm I suppose. I swapped out the jets and took it out for a good rip last night. Slow speed roll on to WOT. No hangups or popping on overrun anymore. Plugs looked good. I will run it like this for a bit then re-evaluate. Still running the oem needles so maybe that would be next. Gain a few mpg hopefully!

[Paladin528]

Corndog:
I had no issues finding the keihin jets when I replaced my slow jets a couple of weeks back.  They were under $5 each.

[Corndog]

Corndog:
I had no issues finding the keihin jets when I replaced my slow jets a couple of weeks back.  They were under $5 each.

Where from?