found this guys ,it will help you learn too jett your bike right well it sure helped my learn/understand how to rejett a bike
some of the stuff that it tells you i never even knew haha...
Here's a link which may be easier to read then on here...
XYZ – Domain Names for Generation XYZ®
HONDA CRF50, XR 50, Z50 1992-1999
Purchase these from your Honda Dealer.
Stock Main Jet Size #58
60 Main Jet #99101-187-0600
62 Main Jet #99101-187-0620
65 Main Jet #99101-187-0650
65 Main Jet #99101-187-0680
70 Main Jet #99101-187-0700
Jetting with stock displacement engine and bolt-on mods:
Stock jetting is appropriate for most applications. Increase Main
Jet size by 2 during break-in.
Jetting with 75cc and smaller engines: Increase Main Jet by 3
sizes. Move needle clip down one position. Stock pilot jet.
Jetting with 76cc and larger engines (larger carb recommended):
Increase Main jet by 4 or more. Move needle clip down one
position. Stock pilot jet.
JETTING BASICS
It is the responsibility of the owner to determine
proper jetting for their engine.
These jetting specifi cations are designed as a rule of thumb. They are
in no way absolute. Variations in air density, specifi c gravity of fuel, altitude
and other engine modifi cations play a large part in jetting. Newly
built engines need rich jetting during break-in. Do not jet for power
until an engine is broken-in.
Plug reading may not work. Revving the engine while it’s sitting in the
garage doesn’t work. Other than Dyno testing, the steps below is the
simplest way you can jet your engine.
1. Find a gentle slope that you can ride in 2nd or 3rd gear. Look for
something that will put a reasonable load on the engine. This will be
your “dyno”.
2. A basic outline of which jet is active at a particular throttle setting:
Pilot Jet = 0 to 1/4 throttle. Needle = 1/4 to 3/4 throttle. Main Jet = 3/4
to Full Throttle.
● Changing the Main Jet size won’t affect how your engine idles or
runs at 1/4 throttle.
● Engine RPM isn’t what determines which jet is active - throttle position
does.
3. Make the recommended jetting changes. Always start rich and
work leaner.
4. Start and warm up the engine, then ride your ‘dyno hill’. Any point
where you feel the engine stumble or hesitate indicates a tuning problem.
Note the throttle position and modify the corresponding jet (1/4 to
1/2 throttle = needle. 3/4 throttle or more = main jet).
5. Only change jetting by 1 step at a time, and 1 circuit at a time (don’t
change needle and main at the same time). Re-check after every
change.
6. Once the engine runs smoothly throughout, you’re jetted!
If you ever notice an abrupt loss of power, or
engine sounds change, shut it down.
some of the stuff that it tells you i never even knew haha...
Here's a link which may be easier to read then on here...
XYZ – Domain Names for Generation XYZ®
HONDA CRF50, XR 50, Z50 1992-1999
Purchase these from your Honda Dealer.
Stock Main Jet Size #58
60 Main Jet #99101-187-0600
62 Main Jet #99101-187-0620
65 Main Jet #99101-187-0650
65 Main Jet #99101-187-0680
70 Main Jet #99101-187-0700
Jetting with stock displacement engine and bolt-on mods:
Stock jetting is appropriate for most applications. Increase Main
Jet size by 2 during break-in.
Jetting with 75cc and smaller engines: Increase Main Jet by 3
sizes. Move needle clip down one position. Stock pilot jet.
Jetting with 76cc and larger engines (larger carb recommended):
Increase Main jet by 4 or more. Move needle clip down one
position. Stock pilot jet.
JETTING BASICS
It is the responsibility of the owner to determine
proper jetting for their engine.
These jetting specifi cations are designed as a rule of thumb. They are
in no way absolute. Variations in air density, specifi c gravity of fuel, altitude
and other engine modifi cations play a large part in jetting. Newly
built engines need rich jetting during break-in. Do not jet for power
until an engine is broken-in.
Plug reading may not work. Revving the engine while it’s sitting in the
garage doesn’t work. Other than Dyno testing, the steps below is the
simplest way you can jet your engine.
1. Find a gentle slope that you can ride in 2nd or 3rd gear. Look for
something that will put a reasonable load on the engine. This will be
your “dyno”.
2. A basic outline of which jet is active at a particular throttle setting:
Pilot Jet = 0 to 1/4 throttle. Needle = 1/4 to 3/4 throttle. Main Jet = 3/4
to Full Throttle.
● Changing the Main Jet size won’t affect how your engine idles or
runs at 1/4 throttle.
● Engine RPM isn’t what determines which jet is active - throttle position
does.
3. Make the recommended jetting changes. Always start rich and
work leaner.
4. Start and warm up the engine, then ride your ‘dyno hill’. Any point
where you feel the engine stumble or hesitate indicates a tuning problem.
Note the throttle position and modify the corresponding jet (1/4 to
1/2 throttle = needle. 3/4 throttle or more = main jet).
5. Only change jetting by 1 step at a time, and 1 circuit at a time (don’t
change needle and main at the same time). Re-check after every
change.
6. Once the engine runs smoothly throughout, you’re jetted!
If you ever notice an abrupt loss of power, or
engine sounds change, shut it down.