Needle and a/f questions..

[BRONX INTRUDER]

Anyone ever take pics of their needles beside the adjustable ones?
Why do the front and rear needles have different part numbers?
They aren't stamped as far as I can tell so what happens if mixed up (front to rear/rear to front)?
Does a/f ratio change with load... Like checking mix at 3k rpm in neutral vs checking it at 3k in gear and moving?

[navigator]

Just a guess, but perhaps the distance of the needle head to the jet is different, front to rear.
Or perhaps the tapers are different.
The slide springs are different front to rear, Possibly the slides as well.
I haven't used adjustable needles, I just add (4mm?) washers.

I don't believe A/F mixtures are affected by load.
JMO

[BRONX INTRUDER]

Just a guess, but perhaps the distance of the needle head to the jet is different, front to rear.
Or perhaps the tapers are different.
The slide springs are different front to rear, Possibly the slides as well.
I haven't used adjustable needles, I just add (4mm?) washers.

I don't believe A/F mixtures are affected by load.
JMO

Probably right but I'll look some more and see if I can tell difference in needles again.
On the shimming... The plastic spacer on top keeps it at the stock level if left in place. So you're replacing it with washers that would equal it's size and then removing some; correct? I think it equaled about five .02" #4 stainless washers and removing 2 would equal raising it one notch.

[navigator]

I left the plastic in place and added washers to raise the needle.
If you need to lower the needle, then yeah, remove the plastic and build with washers to achieve the height you need.

[BRONX INTRUDER]

I left the plastic in place and added washers to raise the needle.
If you need to lower the needle, then yeah, remove the plastic and build with washers to achieve the height you need.

Okay; let's break this down.
The needle starting from pointy tip has the spring, 1 stainless washer, clip, plastic spacer and the plate that holds it in place.
Being that the spacer is held and pressed against the holding plate by clip and spring.. No amount of washers under clip would elevate needle.. It would only compress the spring. Makes sense?
Removing plastic spacer and putting a stack of washers on top and removing some as needed would allow clip and needle to rise.

[hillsy]

The needle starting from pointy tip has the spring, 1 stainless washer, clip, plastic spacer and the plate that holds it in place.

That is a really odd set-up - most needles will have the spring on top so it pushes the needle down onto the base of the slide. That way it allows the needle to move up if there is an obstruction in the needle seat. And in that scenario (if you don't have a c clip to adjust) you shim the needle underneath the clip to raise the height.

[BRONX INTRUDER]

The needle starting from pointy tip has the spring, 1 stainless washer, clip, plastic spacer and the plate that holds it in place.

That is a really odd set-up - most needles will have the spring on top so it pushes the needle down onto the base of the slide. That way it allows the needle to move up if there is an obstruction in the needle seat. And in that scenario (if you don't have a c clip to adjust) you shim the needle underneath the clip to raise the height.

You've never opened them to see?

[navigator]

This^^
What hillsy sez.

[BRONX INTRUDER]

This^^
What hillsy sez.

Not how it is on the vs1400.

[BRONX INTRUDER]

Skip to 14.20
https://youtu.be/hQ5_pLj9qfw

[hillsy]

This^^
What hillsy sez.

Not how it is on the vs1400.

Not saying you're wrong - just it's odd. Most needles have the spring up top.

Never had a 1400 carb apart - but here is the 1500 needle set-up:



Spring is above the clip and you shim the needle up with a washer under it.

[BRONX INTRUDER]

This^^
What hillsy sez.

Not how it is on the vs1400.

Not saying you're wrong - just it's odd. Most needles have the spring up top.

Never had a 1400 carb apart - but here is the 1500 needle set-up:



Spring is above the clip and you shim the needle up with a washer under it.

Yeah.. That's weird. Completely opposite. Lol.

[navigator]

The 800 is also the same as hillsys picture.
Try it that way on your 1400, I can't see how the other way would work...they all use Mikuni carbs.

[BRONX INTRUDER]

The 800 is also the same as hillsys picture.
Try it that way on your 1400, I can't see how the other way would work...they all use Mikuni carbs.

vl1500 - skip to 4min
https://youtu.be/Z_wWHJArWD0
The setup and holder are different. I can remove spacer which would raise needle about 3 slots. Placing it under clip would maintain same spring tension at that 3rd slot.
Moving spring to top of needle is not doable on the vs1400 because there's not enough needle above clip and there's no way to get the plate down to compress spring and screw it in. The vl1500 and i guess vs800 have that hollowed tube holder with rubber o-rings that you just press it down over spring and done.
Dunno why they made it different than the others but I'm not worried about it. Lol. Was more curious about differences in needles from front to rear and why I don't see markings on them if it's important.
Also the engine load question but I guess it maybe doesn't matter..