Pit Bike purchasing for NEWBIES
Crucial, Factual Information for the Potential, or New Pit Bike owner
Contents
What to expect when purchasing a pit bike Online …………………… Pg 2
Dealers, Vendors, and Warranties ……………………………….......... Pg 2
Which bike is for you? ………………………………............................ Pg 2
Maintenance and Repairs ………………………………........................ Pg 2
Pre-ride preparation and inspection ………………………………........ Pg 3
Start-up and Engine Break-in procedure ………………………………. Pg 4
Fork Servicing, Conventional …………………..................................... Pg 5-6
Fork Servicing, Inverted (upside down) ………………………………. Pg 6
General Torque specs ………………………………............................. Pg 7
Setting the Sag on your bike ………………………………................... Pg 8
Links to:
Manufactures, Vendors, Dealers, Parts, etc ………………….....…. Pg 9
Recommended modifications ………………………………................. Future
______________________________________________________
Much of the information contained in this file pertains to 125cc - 160cc YX engines found in many
Mid sized Pit bikes with 50cc based transmissions, but can be a useful tool with virtually ANY
Pit bike.
The majority of the information was compiled from pit bike owners who are members of various
pit bike forums. I am NOT responsible for any misleading information, or damage you may cause
to your bike from utilizing this information. Tweek and maintain your bike at your own risk!!!
**This file will be updated periodically with important Pit bike
information and recommendations.
Last Update: Jan 24, 2009
What to expect?
This information comes from my own personal experience and is factual.
For starters, if you are considering a popular, ‘Higher end’ mfg., such as Pitster Pro,
OGM, SSR, Moto-vert, G2 Moto, etc, you will most likely
NOT be able to see one in
person at a local dealer. Because of that, you will not be able to compare different
brands or models in person either.
Why you ask?
Because purchasing a Chinese pit bike isn’t like purchasing from a Japanese
company that has Nationwide dealers. Technically there are no ‘dealers’ in the pit
bike industry. 99% of all bikes that are ordered from the so called ‘dealers’
across the Internet are actually just drop shipped from directly from the Mfg. If
you order your bike from an internet ‘dealer’ on the East coast, your bike may
actually be shipped from California. The person that you purchase the bike
from will more than likely never see the crate or bike in person.
Dealers, Vendors, and Warranties
I am new to the pit bike scene as well, but it doesn’t take long to weave your way thru
the wool and figure it all out - all of the ‘stuff’ that isn’t brought to the table
before
you buy a bike. The details about pit bikes are sketchy at best. Become an investigator
and
DO YOUR HOMEWORK before laying down the cash. I think that most
reputable Internet dealers will do as much as possible to make your purchase a
positive experience.
Warranty? I’ve never saw an actual written warranty. You won’t get any of the usual
paperwork that comes with Jap bikes. No owners or service manual. Don’t plan on
purchasing a manual after you buy a bike either. They do not exist.
Which bike is for you?
Like I said above, do your homework before you make a purchase. If you’re reading
this, you have all the means of studying any bike that you may be considering.
Become familiar with the
“Search” function of forums. They are your best friend. Of
course you need to consider the source of the post you may be reading from. Learn
how to weed out the BS.
Maintenance and repairs
You need to be able to perform routine maintenance and light repairs on your own.
Many major dealers will refuse to work on your Chinese bike and will not have parts
readily available. You will mostly rely on Internet dealers to supply help and parts.
Pre-ride preparation and inspection
The recommendations below come from many sources including members of various Pit Bike forums.
Take the tank off and blow it out. Plastic shavings have been reported inside the tank
Change the oil right away before you start the engine with 10w40
non synthetic oil
Loctite all, yes ALL nuts and bolts with Blue loctite. Use RED locktite for the chassis
and subframe bolts, Clutch nut, and oil slinger
Check all electrical plugs. Secure and clean as necessary. Add non-conductive grease
if available
Check all controls for proper operation
Lube throttle and clutch cables
Glue, and/or wire tie the handlebar grips!
Lower fork tubes to approx. 3/8” - ½ “ above Top Triple clamp. Adjust if necessary
after riding
Check and adjust shock/fork settings (compression and dampening)
Add an inline fuel filter
Grease steering head bearing and tighten
Grease swing arm pivot bolt with anti-seize lube
Grease front and rear axles with anti-seize lube. Do not grease the threads
Check Valve lash before cranking the engine! They are notorious for being to tight
and can cause major damage if ran too long, too tight
Remove the cam chain tensioner and reinstall it... It’s self explanatory how it works
Check tire pressure
Check chain slack. 1” - 1.5” slack at middle of swingarm
Check Clutch nut and Oil slinger nut for tightness. They are known to become loose
Note: The clutch nut and oil slinger nut require the use of a special, proprietary tool
Level carb - side to side
If gas overflows, set the float level. Stock float levels are also known to be out of
adjustment sometimes
Add rim locks if possible. At least on the rear rim
Engine break-in
Loosen float bowl drain screw until gas runs out of the overflow tube. This ensures
you are getting gas to the carb.
Gas on, choke off, no throttle, try to crank. If it will not crank without the choke,
choke the carb and try again. If it still will not crank after 15 -20 kicks, turn the idle
screw in (higher idle) about 1 - 1.5 full turns and try again without the choke
Once running, listen for noises. Run for 2-3 minutes. Let bike get warm/burn in the
pipe, then shut it down
Make sure you heat cycle the motor a couple of times to seat the rings
Allow engine to totally cool down between each heat
Change oil after each heat cycle and Clean drain plug of metal flakes
Check the valve lash again after 2-3 heats
Listen for a internal clutch noise. Some of the YX’s clutch basket nut comes loose
Check oil level. (look for debris/color/smell)
Go for short ride testing clutch,shifting,brakes. Check chain tension and wheel
alignment
Look over bike for loose or missing bolts.
Look for leaks on engine and suspension
Check fuel line for leaks
Recheck engine oil level
Check to see if tire has slipped on rim
Check headset for tension
Go back and re-torque the head after a hour or so.
Service oil in forks soon after break-in (more on that below)
Fork service for ‘Conventional’ forks
This is “Precision 50’s”, aka “Old schools” advise. Props to him!
Steps 1 through 12 is based on
Conventional fork service
not Inverted forks.
Step 1: Put your bike up on a stand to where the front end will hang off the floor. Then if
you have a front drum brake remove the brake cable from the front brake lever. If you
have a front disc brake remove the caliper from the caliper bracket and place a small
wedge or piece of thick cardboard between the brake pads (this is so the caliper can not
be mistakenly applied.
Step 2: Remove the front wheel loosen the axle remove it (pay attention to which side the
wheel spacers go on) if the axle will not slide out easily then tap it out with a rubber
mallet and drift and set the wheel aside along with the brake drum and brake cable or the
front brake disc
Step 3: now if you have disc brakes remove the caliper and let it just hang out of the way.
also its good to remove the front number plate just so you have clear access to the all the
bolts.
Step 4: now it a real good time to loosen the nut on top of the fork tubes on each fork as
its a lot easier to loosen while they are held by the triple clamps.
Step 5: use the correct size socket or wrench to loosen the left side of the upper top
clamps (pinch bolts) and the lower bolt on the lower left side clamp (do one side at a
time). now slide the fork tube out of the clamp and over to your work area.
Step 6: Now with one side off its time to take it apart , now’s a good time to have
someone else around to be able to hold the forks upright. but not necessary. with the fork
in the upright position on the floor of your work area. remove the top nut off the top of
the fork tube. remember the fork is spring loaded and has fluid inside.
Step 7: now with the Cap off the fork, place the complete fork assembly over a large
bucket or Pan and pull the fork spring out of the fork tube... the bucket is there so you do
not make a mess. Now set the spring aside on a clean towel (if your going to re-use it) or
replacing the spring with aftermarket HD springs. now dump the remaining oil into the
bucket or large pan, also what your going to want to do is Pump or (compress) the fork to
extract the oil out continue until all oil is out.
Continue to next page…
Step 8: now fill the tube with fork fluid (fork oil) I recommend 20wt and 100mm +/-
2mm of air gap with the spring out (this is going to be anywhere from 3.5 ounces to 5.5
ounces depending on the forks) so start out with the lower amount and work you way up
till you get the air gap.
Do this with the fork tube compressed. Once you get the proper
level and its set, slowly pump the fork tube to get the air bubbles out. once all the bubbles
are out re-measure the air gap and if more fluid is needed do it now
Step 9: now extend the fork tube and slowly drop in the old or (new HD Spring). when
the spring is in re-install the fork cap being very careful not to compress the fork tube and
spilling out the fork oil.
Step 10: Re-install the fork up into the fork clamps do not over tighten the bolts or pinch
bolts ( 8-10 ft lbs of torque). also tighten the top nut cap once the tubes of the fork are
tight in the clamps do not over tighten the fork cap!!!
Step 11: Repeat steps 5 through 10 to the right side fork tube
Step 12: put your front wheel back on make sure the spacers are on the correct side and
torque the axle nut to 32ft lbs. put the brake caliper on the fork leg if you have disc set-up
and or reconnect the front brake cable up to the brake lever.
Note: the Air Gap is the measurement from where the fork fluid level sits inside the fork
tube in reference to the top of the fork tube. the distance between these two is the air gap
Servicing “Inverted” (Upside Down) Forks
Follow the link below to Outlaw Power Sports for a printable PDF file.
http://www.xpcpowersports.com/Tech/Fork_How_To.pdf
General Torque Specs for 50cc based transmissions (most pit bikes)
Thanks to “Mighty Mace” for the following information.
Frame
Front Axle: ………….. 45-55 Nm 36.88 ft. lbs
Rear Axle: …………… 50-60 Nm 40.57 ft. lbs
Swingarm: …………… 45-55 Nm 36.88 ft. lbs
Triple Tree Bolts: ……. 30-40 Nm 25.81 ft. lbs
Shock: …………….…. 38-42 Nm 29.50 ft. lbs
Engine Mounts: ……… 33-35 Nm 25.08 ft. lbs
Steering Stem: ……….. 40 Nm 29.50 ft. lbs
Engine
Ignition Cover: ……… 10-12 Nm 97.36 in. lbs
Clutch Cover: ……….. 10-12 Nm 97.36 in. lbs
Clutch Adjuster Nut: ... 10 Nm 88.51 in. lbs
Flywheel: ……………. 45 Nm 33.19 ft. lbs
Clutch: ………………. 45 Nm 33.19 ft. lbs
Oil Pump: …………… 10 Nm 88.51 in. lbs
Oil Drain Plug: ……… 25 Nm 18.44 ft. lbs
Engine Studs: ……….. 10 Nm 88.51 in. lbs
Cam Bolts: ………….. 12 Nm 106.21 in. lbs
Head Bolts: …………. 10-12 Nm 97.36 in. lbs
Cam Cover: …………. 10-12 Nm 97.36 in. lbs
Spark Plug: ………….. 10 Nm 88.51 in. lbs
Exhaust: ………….….. 12 Nm 106.21 in. lbs
Setting the Suspension “Sag” on your Pit Bike
Two main ingredients to a great handling bike is the race sag and free sag.
Race sag, is the amount the shock compresses from fully extended with the rider on
board. The rear race sag is probably the most-important suspension setting you need to
address before hitting the track or trail.
Free sag is how much the bike sags under its own weight - without a rider. I will omit this
step since Free sag will not work out as well on Pit bikes. In most cases you can get away
with just setting your
Race sag.
To set the
Race sag.
Put the bike on a stand with the rear wheel off the ground and measure from the axle
nut to a point directly above it on the bike. I mark a spot on my rear fender directly
above the bolt. Write that measurement down as #1.
Now take the bike off the stand and let it stand upright. With the bike off the stand,
compress the shock a few times.
With all of your riding gear on, sit on the bike in the attack position (head roughly
over the cross brace, elbows up and out and feet up on the pegs), have someone hang
onto the bike for you and take a measurement again (#2). Subtract #1 from #2. The
amount of sag in most cases should be approx. 2”.
Measurement #1 -minus- measurement #2 should = approx. 2”
If you have less than 2” sag, loosen the preload on the spring and recheck
measurements.
If you have more than 2” sag, tighten the preload on the spring and recheck
measurements.
Links
Manufacture websites
OGM ………….
http://www.ogmotorsports.com/
Pitster Pro ……..
http://www.pitsterpro.com/home.php
SSR ……………
Welcome to SSR Motorsports!
MotoVert ………
Motovert - Australia number 1 brand of performance mini bikes
G2 Moto ………..
Live » Page 1 of 147
Bikes and Parts
Factory Power House inc.
CHPUSA.NET
http://www.ogmotorsports.com/parts.php?category=2
Ahp Minis
http://www.outlawpowersports.com/
TBolt USA: Pit Bikes, Engines, Parts, SSR, Pitster Pro, CRF50, KLX110
http://www.sgr-usa.com/
KLX110 Parts - Minibike and Pit Bike Accessories
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