o-ring and carb needles

[user 16790]

after reading a few more recent stories on the dreaded oil o-ring failure I became paranoid about riding my bike, so I ordered the o-ring and sump gasket from EXACTREP, and just for my own assurance I bought a new rubber bung/damper that fits to the oil pipe too,
yesterday I took my sump off and saw that my oil o-ring was perfectly fine, no signs of it coming out which was a relief, as it was ok I didn't bother taking it all apart to fit the new o-ring but I did fit the new rubber damper thing, side by side the new one was almost 1mm taller than the old squashed one so it should make sure it still stays in place, it is quite noticeable when refitting the sump how much pressure it takes to press it against the damper,

any way a few months ago I was given a set of carbs as spares which was great as I needed new diaphragms,
what I noticed when changing them over was that the needles were shorter in the spare carbs than the ones in my bike, the number on the shorter needle corresponds with the UK needle number so I'm assuming the ones in my bike are the California spec ones,
my question is would I notice any difference in changing my needles to the shorter ones,
I should say that I can't ride the bike hard as my wrist is knackered so I can't turn the throttle to full but it still goes fast enough for me

 

[Fire-medic]

Is yours a CA-spec bike, w/CA-spec carbs? The CA carbs have very-noticeable different castings. I've used CA-spec carbs which I believe to-be unaltered from stock, though I don't recall that I did anything besides check the main jet sizes, when I disassembled them for an ultrasonic bath cleaning.

Pretty-sure it's the #2 cyl (left front) carburetor which has the port for the California emissions canister.

#1 cyl=left rear
#2 cyl=left front
#3 cyl=right rear
#4 cyl=right front

 

[user 16790]

I don't know for sure, it was listed as a USA import so as the manual I have lists two different needles I guess mine must be a california spec, is it worth trying the rest of the world spec shorter needles or do they not make much difference, I guess the shorter needles richen the midrange or something,
I'm in England by the way

 

[Fire-medic]

This may help to see about your bike's market for-which it was built. Remember, engines can be swapped. Different years, different letters, numbers. You could have what the Rickman Brothers called a 'metisse,' a bastard. A Camadian bike, A USA engine for a year different from the frame, and carburetors designed for California.

Resource:
http://vmoa.net/VMX12-Service-Manual01.pdf

 

[user 16790]

my frame and engine fits the USA spec then but maybe the carbs are different or have been worked on, maybe I'll just try those needles as they are easy to get at

 

[dannymax]

Check the numbers stamped on the needles.