 Do these things to your bike and you'll
be happy all year long. I charge pro racers big bucks for
this service and they keep coming back! All this work should
only take a weekend or two to complete. The following is
really just common sense and what I think is important to
do to a bike. It also comes from years of being around dirt
bikes. |
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| If you want to install grease fittings in the
suspension linkages during your overhaul, mark with a Sharpie
where you want them to go BEFORE you take off the shock and
swing-arm. Mark the locations for the grease fittings so
that they don't interfere with anything. Remember that you
have to be able to get to them with a grease gun too. |
| Disassembly & Inspection |
| 1. |
Take of the swing-arm, linkage,
pipe, sub-frame, rear wheel assembly, seat, air-box, etc.
In other words, strip the entire rear half of the bike down,
from the carburetor on back. |
| 2. |
Once your bike is taken apart, we'll put it
back together piece by piece with modifications that cost
next-to-nothing. |
| 3. |
Take a look at ALL of the welds on the frame.
Check for flaking paint at the welds. This may indicate a
crack. If it has been cracked a while, you may see a small
rust trail. If you find a crack, get it fixed! These frames
are mild steel, so almost any welding method will work. |
| 4. |
This is a good time to tighten EVERY bolt
on the main frame too, as they're easy to get to while the
rear is out of the way. Important: Check the engine mount
bolts and make sure they're tight. |
| Rear Wheel Assembly |
| 1. |
The rear wheel assembly is next.
Pull the axle spacers out of the seals on both sides (mark
them R and L) so ya can see the outside of the bearings.
Stick your finger in to the inner race of the bearing and
turn it. Feel for smooth turning with some resistance. If
it turns real easy, there's not enough grease in the bearing,
and if it's a little rough, it's junk. It should not be a
bit loose! |
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| Replacing Wheel Bearings |
If you have a bad bearing, find a punch that is long
enough and thin enough to go clear through the hub like
the axle does. There are two sealed bearings, one on
each side of the hub, and between them on the inside
of the hub is a steel "spreader" tube. Stick
the punch in the opposite side from the bearing you want
to knock out and kind of pry the spreader tube sideways
a little so the punch can get a bite on the inner race
of the bad bearing. Hit it gently then move the spreader
90 degrees and tap some more. Work the bearing out as
straight as you can.
If you take the bad bearing to a bearing/belt/chain
dealer, there's a great chance you will be able to purchase
a replacement bearing for one-third to half the cost
of what someone will sell you an OEM part for. When you
get the new one, just tap it into the hub until it bottoms-out. |
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| 2. |
After the bearings have been installed, put the spacers
back in on the proper sides and that's done. Don't forget
to put the spreader back in BEFORE you seat the last bearing. |
| 3. |
Check the spokes for tightness. If you find some that don't
seem as tight as the others, tighten them up. |
| 4. |
Replace the brake shoes or pads at this time if needed. |
| 5. |
This is the time to install a new tire and tube if needed. |
| 6. |
Check the sprockets for wear and tightness. |
| Rear Suspension |
| 1. |
Inspect the swing-arm for cracks or damage and get it fixed if needed. |
| 2. |
Now we're going to install the grease fittings in the links. |
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| Installing
Grease Fittings |
Go to an auto parts store and buy three grease fittings.
They come straight, 45° and 90°. Get the ones you need
with a 1/4-28 thread. Don't forget to get a 1/4-28 tap
(bottoming tap preferred) and two drill bits in the size
of #3 and 1/8".
Take the needle-bearings out of the link and clean the
grease out of it. Find the spot you marked at the beginning
and determine the best angle to drill that will go into
the space where the needle-bearings were located. Find
the THICKEST part of the casting that will put the grease
fitting close to where you marked. Drill the first hole
with the 1/8" bit through the casting AND the wall
of the outer race. Now take the #3 drill bit and drill
through the same hole again BUT stop drilling when you
hit the steel bearing race.
Do NOT drill this big hole through the race as you did
with the little one. Screw the tap into the casting and
work it in-and-out a little at a time un til you have
threads. Once the tap hits the race it wont go any further
be cause it wont fit through the 1/8" hole in the
bearing race.
Important Note: Go gently be cause if you break the
tap off in the hole you're going to have another job
on your hands! The tap is harder than a drill bit and
real hard to get out if it breaks.
Clean all the chips and burrs out and take the burrs
out of the race where the bearings ride with a Dremel
Moto tool and/or emery paper. Screw the grease fitting
in and your done. Do this to all locations where you
want grease fittings. |
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| Reassembly |
| 1. |
Once all the above is done, it's time to put it back together.
Lightly grease all bolts, axle, etc. and install the swing-arm,
links, wheel, subframe, etc. on the bike. |
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| Rear
Wheel Alignment |
When you put the rear wheel assembly on and get ready
to adjust the chain, find the center of the swing-arm
shaft and mark it with a center punch (dimple) on each
end. This is for measuring to the rear axle for wheel
alignment. You will find out how close the snail adjusters
really are. Sometimes they're rite on and sometimes they're
not. Put a punch mark in the center of the rear axle
on each end also. I made an adjustable caliper for this
but you can use a tape measure or steel rule.
Adjust the chain as normal and snug the axle nut. Now
measure the distance from the center of the swing-arm
shaft to the rear wheel axle on both sides. This measurement
MUST be exactly the same, whether or not the snail adjuster
notches fit. If the snail adjuster notches don't fit
when you know the swing-arm shaft and axle are parallel,
you can modify the snail adjuster so it does fit. It's
the little things combined together that make a world
of difference over-all! This is just one of them and
well worth the effort. I didn't tell you to clean and
lube the chain as you already knew that anyway. |
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| 2. |
Once you have the back half of the bike done, we'll work our way forward. |
| Intake & Carburetor |
| 1. |
Don't put the air-box on just yet. Take the filter out
and service it as normal. Clean the air-box inside and out
real good. Where the boot attaches to the box, on the INSIDE
of the box, smear some clear silicone around the joint and
smooth with a wet finger. Remove the excess silicone, as
all you want is a final barrier to keep dust and water from
getting sucked in between the joint of the box and the boot.
(Some guys don't use silicone as I described, but they do
use grease. The choice is yours.) |
| 2. |
This next step is really important, as a lot of engines
get "dusted" from this source. (Some leak, some
don't) Grease the sealing lip of the air filter where it
mates up to the air-box and install the air filter. Now,
in the end of the boot that connects to the carburetor, smear
a thin coat of grease around the inside of the boot and coat
the inside as far up as you can reach with your finger. THIN
coat! Real THIN! This will catch the dust inside the boot
before it gets sucked into the carburetor if any gets past
the air filter. Now install the air-box with a thin coat
of grease between the boot and the bell of the carburetor.
You are now done with the air-box, except where the side-panel
mates to the air-box - use grease there as well. |
| 3. |
Next little "ditty" is sealing out dust and
water from the carburetor itself. After your done with this
mod, the bike will idle submerged in water clear up to the
top of the air-box near the bottom of the seat, so it's worth
the effort! |
| 4. |
Yank ALL the black rubber vent lines off the carburetor
and go to a store that sells R/C model airplanes and cars
and buy 6' of silicone (you can also use neoprene) fuel line
made for gas R/C engines. Install the new hoses on the carb.
and rout them up somewhere high on the frame and secure them.
At least as high as the top of the air-box. Now take some
silicone and seal where the throttle cable goes into the
top of the carb. A little grease on the threads of the slide
cap is good too. Install a fuel filter and you're rockin'
as far as the fuel system goes. |
| 5. |
Next on the agenda is the crankcase breather tube. The
large (1/2") tube coming from the top of the lower engine
cases has to go. It's the one with a cute little "T" fitting
with one tube going up and one tube going down. Remove it
and throw all this away! Buy a 3' piece of neoprene tubing
and a small hose clamp. Connect one end to the nipple on
the engine with the clamp and route it up to the air-box
opening at the top. Install a filter (available at an auto
parts store) on the end and just stick it into the top of
the air-box. Let it dangle as long as its not near the air
filter. It could wear a hole in the air filter and that would
NOT be good. You may have to trim some the foam off the air-box
where the seat seals against it (if your bike has foam) to
allow the tube to fit between them without collapsing. The
filter on the end of this breather tube is important because
the air is being drawn into this tube, as well as being forced
out. |
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An alternate to the mod above might be to install a bulkhead
fitting into the airbox so the breather tube just connects
to it as opposed to going all the way up to the top of the
air-box. Obviously the other end of the bulkhead fitting
needs to either have a short section of hose with a filter
or perhaps you can find a filter that attaches directly to
the bulkhead fitting. |
| Electrical |
| 1. |
With the tank off, clip each wire connector out of the
circuit one at a time and solder the wires back together
using heat-shrink tubing to seal the joint. Do not solder
wires that have spade-lug connectors on the points where
they plug into the coil, CDI box, etc. These are good connections
normally and can be tightened up easily. A dab of silicone
will seal them from moisture and vibration. Once all the
loose ends are taken care of, bundle the wires back together
with electrical tape and secure them to the frame. NOTHING
should be allowed to vibrate. |
| 2. |
Next, remove the kill switch and take it apart. Make sure
the insulation on the wires going into the switch are not
able to short against the handlebar. Silicone works good
for this. |
| 4. |
Remove the timing/points cover and seal around the gasket
with grease. Install a new spark plug and use hi-temp silicone
to seal around the porcelain off the spark plug and the plug
wire boot. Seal where the stator wires come out of the stator
as well. |
| 5. |
While were on the engine, remove the useless counter-shaft
sprocket foot guard, if equipped. This makes it easier to
change gearing and remove crap that gets stuck in the chain
and sprocket. |
| Front-End & Controls |
| 1. |
Block the bike up like you would if you were going to remove
the forks. Take the front wheel off and do the bearing thing
as you did on the rear wheel assembly. Again, check the spokes
and tighten, replace the brake shoes or pads, etc. just as
you did on the rear. Check EVERYTHING on the front wheel
assembly. When you put the wheel back on, take note of the
axle clamps. Some clamps have a direction indicator cast
into the part. Lightly grease the axle and install the front
wheel and axle on the forks. Insert the axle into the fork
leg snug but not tight. Now install the clamps with nuts
and screw them by hand until the clamp is a little closer
at the bottom than it is at the top. Adjust the nuts until
everything is seated and all have the same finger-torque.
Now tighten the top nuts with a wrench. This will pull the
clamp parallel and the bottom nuts will be tight as well.
The reason for this tightening procedure is to keep the axle
from tightening itself into the fork leg so tight that you
cant get it loose on the trail with smaller tools. |
| 2. |
Now we will grease the steering head bearings. Remove the
master cylinder, clutch perch, kill switch, etc. as you would
if you were changing the bars. Just let them dangle. Loosen
the top triple-tree clamp bolts, remove the nut that holds
the top tree on the steering stem, and tap the top tree off
of the fork tubes and stem with a plastic hammer or piece
of wood. Now you're looking at two large nuts that kind of
look like the ones on your shock that set the spring tension.
If ya have the right tool, then use it. If you don't, then
use a punch and hammer to loosen and remove these nuts. The
whole front-end will fall out of the steering head until
the tire hits the floor. The top bearing will be sitting
in its race along with a seal. You can just pick them out.
The bottom bearing and seal will be on the steering stem
and don't usually get removed because they require a press. |
|
Note: The stem doesn't have to come clear out of the head
in order to grease the lower bearing. Just leave it where
its at and pack the bearing with grease. "Packing" means
forcing the grease into the bearing, not just smearing it
on. |
| 3. |
Repack the top bearing too. Lift the front-end back up
into the head enough to get the top bearing, seal, and one
nut on the stem. Use a special tool or a large pair of pliers
to tighten the top nut. Make sure nothing is binding as you
snug the nut down. Turn the forks lock-to-lock a few times
as you snug up the nut. Now put the front wheel back on the
ground with the bikes weight on it. Loosen the nut. Now just
snug the nut back down. Not tight. No torque, just snug.
Thread the second nut on and as you hold the first nut with
something so it doesn't turn, tighten the second nut down
against the first. This is a jam nut and must be tight. |
| 4. |
Now you can put the top tree back on and tighten the last
nut and fork leg pinch-bolts. |
| 5. |
There is also a right way to put on handlebars. You're
going install the bar clamps just as you installed the axle
clamps. The reason for this is SAFETY. What were after is
bars that will rotate forward with a big hit, but at the
same time, not rotate backwards when you land heavy on them
with your hands. Mount the bars and snug the bolts down with
your fingers as you did with the axle clamps. Make sure the
bolt hole with the dimple is facing forward. Now adjust the
bolts so that the clamp gap is a little closer at the rear
than it is at the front. Now, holding the bars where you
want them, tighten the two front bolts. The rear bolts will
be tight, but not as tight as the front bolts. |
| 6. |
When you put the perch, master cylinder, etc. back on,
snug them up finger tight and adjust them to suit you. Then
tighten them up but not real tight, as need to rotate in
a fall. This will help keep you from braking levers in a
fall. |
| 7. |
Get a cable luber and use it! |
| 8. |
Ride the bike and check EVERYTHING. Don't forget to pump
up the brakes before you ride. |
