Randy's Cycle Service Explains Carburetors, Choke & Cold Starting - vintage motorcycles. Randy's Cycle Service & Restoration in central Virginia USA. We service & restore all makes & models. We do not source or stock parts or sell vehicles. Technical advice starting at $25. Randy's Cycle Service & Restoration, www.rcycle.com
How Motorcycle Carburetors work and how to tune and clean them
Here's a link to the kind of carb cleaner I like best (it IS the best)
hey... awesome video..nicely explained !
just one question. Please do tel me wts AIR NEEDLE and LOW JET used for
again. ? i mean how and what do they work?
The air needle is like a transitional restriction to increase vacuum
pressure and tapered to prime the main jet flow gradually to ramp up fuel
flow from the idle/low circuit to the main circuit. Think of the circuits
like gears or stairs. The needle covers transition between 3rd gear to
about 5th gear on a six speed. It overlaps basically. Fuel is getting by
it from the idle/low- on through to where it's completely out of the way of
the main jet and the main jet fuel flow is roaring like the
Without the needle the carb would work, but not as smoothly through middle
throttle (where most people ride and have the most fine input or throttle
roll back and forth.
The low jet is like second gear on a transmission. You can shift from 1st
to 3rd, but again you risk stalling and it won't be as smooth. Also there
isn't really the mechanical inertia to carry the process on like you have
with a rolling vehicle with a flywheel on the engine and the wheels
turning. The pistons still create vacuum every other time they go down,
but air just doesn't have the punch that steel does when in motion.
The circuits in a carburetor have to be there or you would have a limit on
RPM range. An idle jet can't deliver enough fuel to really scream, and the
main jet couldn't go slow and would be VERY hard to start because the
engine would have to be spun up really fast. So you have usually four or
five circuits (I want to say jets, but their physically different) that get
air flow like stairs as the throttle opens. They are typically 1. Starting
circuit (choke on) 2. Idle circuit 3. low jet 4. Jet Needle 5. Main jet.
How Motorcycle Carburetors work and how to tune and clean them Check out
my other channel here http://www.youtube.com/watch?v=1KKvwMaIotA
How a cv carburetor works. Sound of a YAMAHA XTZ750 Super Tenere.
How a carburetor works, schemes and explanations
This video explains, not in too much detail, how a 28mm Walbro diaphragm
carburetor works (using mainly schemes to point out what happens inside).
It explains what occurs at the venturi, what the butterfly valve is for,
how the needle doses the amount of fuel, and how does the diaphragm slide
How to clean a carburetor in 15 minutes
These same instructions apply to most other slide throttle style carbs from
Mikuni, Keihin, etc
You can also take out the idle screw and spring while cleaning if you wish,
but typically that isn't required.
How to adjust the jets on motorcycle carburetors
This is a brief introduction to the fairly touchy process of re-jetting
your carbs. The techniques discussed here are fairly universal to most
carburated motorcycles, but not all, so your first step in performing carb
tuning should be to consult your repair manual and online forums. Hopefully
this video can demystify a lot of the process for you, so that you have the
courage and interest to do this yourself. Let me know if you have any
Motorcycle Mikuni CV Carburetor Cleaning for Suzuki, Honda, Yamaha Tutorial
Links below. Step by step instruction on how to disassemble, clean and
assemble Mikuni CV Carburetors for Suzuki, Honda, Yamaha motorcycles... I
hope you find this tutorial informative if long.
For parts for your Vintage Japanese Motorcycle, please visit
http://z1enterprises.com These guys always have the best prices and fastest
shipping. Thank you for watching.
Anti Seize Lubricant
How to change piston / top end rebuild 2002-2007 Honda Cr 250
Join the FREZ PRODUCTIONS Facebook site!
I`ve got many nice comments for making the "Honda Cr 125 piston / top end
rebuild" movie. In this movie, I show in good detail how to chance the
piston on your two stroke Honda Cr 125.
A similar movie for the Honda Cr250 would be nice, and that's what I have
Hope you like it!
The bike used in this movie is a 2007 Honda Cr250.
Always use the right manual for your bike! The 2002-2007 Honda Cr250 bikes
are very much alike but there are some changes. That's why the right manual
for your year is important.