How does it work? (needle in carb)

[250RWANTER]

Just curious what makes it work and what it does. Just curious as I just messed with it while working on the 1980 Honda 110 (read NEED HONDA 110 help!!!) and it helped the situation.

I assume it regulates how much gas comes in from the tank somehow.

What are the different grooves for? How do you know when you need to move it from its current position?

Do they ever wear out and need to be replaced? How do you know when that time is?

What does it do exactly?

If I am making adjustments on it, I want to know what its doing and why its making a difference, besides that someone just told me too do it

Thanks!

[Derrick Adams]

I shouldn't reply to this at a risk of looking like an idiot, but I believe that the adjustment on the needle is how much fuel flows thru the jet at different positions in the transfer from idle to WOT.
When the needle is lowered into the jet (moving the E-clip up) this would effectively lean out the air/fuel mixture in partial throttle. When the throttle is at rest, the needle is mostly blocking the jet, which limits fuel. Then the idle screw is used to adjust how much air flows past the slide to control the rpms at idle. If your idle is where you want it, and it seems to be running rich, then you would lower the needle to restrict fuel flow.
This may not be the case on all carbs though, I think some actually have an idle enrichment screw, which would allow you to adjust idle mixture without tearing your carb apart.
This is just my thinking on this, I am no Mechanic. I have had good luck in tuning my bikes this way though.
Oh yeah, the needle should have a smooth taper from top to bottom, if it has ridges I would say it would need to be replaced. I have never seen one wear out though. You may want to pull off the bowl and clean your jet, if your having issues. It wouldn't take much to keep that needle from hanging up.
I hope this is accurate. I catch enough grief on this board already.

[jeswinehart]

please don't take this as mean or personel 250rwanter ,,, i ain't like that.
but you are in serious need of a manual ,,,

great reply derrick !



john

[localtalent]

You definitely want a manual for that, I would have destroyed my '84 110 even worse than I already have (I'm very new at this too, see my two posted threads).

However, my gripe is that the manual DOES NOT EXPLAIN HOW IT WORKS. It is up to you to figure it out from the diagrams.

However, auto.howstuffworks.com is an invaluable resource, with links to other sites for more information. The carb one isn't as good as the others, particularly the engine and limited slip differentials with 3-D graphics and animation, but it's passable. Some of the links are better.

Good luck to you.

[250RWANTER]

No offense taken! I KNOW I need a manual, but I have to order one. I actually put a wanted ad in the classifieds where. I was planning on going to the dealer today and ordering one....unless there is an online source...the dealer tends to be $$$ on most stuff.

Is there better shop manual than others? Any brand to stay away from?

[eh_tee_see]

just get a Honda service manual, I never have cared for Clymer manuals and thats all there is.

[250RWANTER]

Do I have to get the Honda Service Manual from the dealer?
I saw the Clymer and Haynes ones for about $20....but not the actual Honda one.
Got any links?

[daputz]

read this, it will explain "how it works"

http://204.71.0.3/motoprof/moto/mcyc...1/carb101.html

[mywifeknowseverything]

Or this
http://justkdx.dirtrider.net/carbtuning.html