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Disclaimer: PLEASE
read entire instructions prior to attempting this for the first time. Be
familiar with the pics and the info to each one, as it may be very
important not to skip!!!
This is a technical job. On a scale of 1-10 on difficulty
(10 hardest), this one ranks up there close to a 8-9... 10 being engine
rebuilding!!! The job entails use of tools not commonly found
in the avarage houshold tool box, so lets get tools sorted out:
You will need:
-
1/4 inch socket wrench
and socket set... most often you use the 8mm socket, and the 10mm
socket... BUT-the Valve tappet is 9mm.
-
3/8 socket wrench and
set- sockets: 5/8 for spark plug, 13mm for rocker assembly and passenger
seat
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metric combination
wrench set, specifically 12mm and 13mm for seat
-
Feeler Guage set (.003
and .004 specifically)
-
3/8 torque wrench and
13mm socket
-
Pencil and white-out
or etching pen
-
Assembly lube
-
RTV
silicone
-
flat-head and phillips-head
(star) screwdrivers
-
rope or bungee for
timing chain
Got those?
First things first, to make your life EXTRA easy, simply use a 12mm wrench
and a 13mm socket and 3/8 socket wrench, and remove your passenger seat by
removing the two bolts that hold it in place! Remove the seat and you now
exposed the whole top-end!
Now... Begin by starting literally from the top!!
Shut off fuel supply, and drain your carburetor. Remove
the carburetor and intake manifold.
This IS necessary in order to remove the chain
tensioner later on. Once you remove the filter/intake tube, the carb, and
then the manifold (10mm nuts), you can start removing the plastic
components around the engine. You really only need to remove the top
section and the passenger (intake fan) side pieces for this task,
therefore, it is unnecessary to remove the exhaust and lower portion of
the plastic, however, as I was performing other modifications, in my pics,
the exhaust is removed. Use the 1/4 inch socket wrench and 8mm
socket for ALL the bolts in the plastic housing.
Now that you got that stuff out of the way, remove the
fan from the flywheel on the passenger side of the engine, again, using
the 8mm socket. Once you have the fan off, take note of where the flywheel
is, and remove the spark plug with a 5/8 deep socket and 3/8 socket
wrench.
With the plug out, you can partially cover the hole
with a finger and turn the engine forward (clockwise) and feel for
compression. using the pencil you have, slide it into the spark-plug hole
once you located the compression stroke. Slowly turn the engine and watch
the pencil... If it goes up, turn the engine a tiny bit more... if it goes
down, back up a tiny bit till it reaches the top again. You want to see
the pencil stick out the farthest, so as soon as you find that (known as
Top Dead Center, TDC), you can remove the valve cover and check your
status!
Again, using the 8mm socket and 1/4 socket wrench,
remove the 2-4 bolts holding the valve cover. Remove the valve cover and
wipe the gasket surface thoroughly with a clean rag... set aside and begin
timing alignment.
Looking at the cam, line up the two small holes
with the top of the engine surface. The large hole should be pointing
towards the seats:
If the markings are correct, and you are on the
compression stroke, TDC, then you are half way there!! Now, etch or mark
your flywheel position so that you can reference it in the future and for
tuning later on. I used an etching pen, but many people use marker or
white-out.
Once that is marked, you may remove the 4 nuts and
washers holding in the rocker assembly. This is 13mm, and the 3/8 socket
wrench. Break all 4 loose first, then remove each one at a time. Get your
rope or cord ready to hang the chain by....
Remove the rocker assembly from the head, exposing the
camshaft. Now, go back to the top of the engine, near the electrical box,
and remove the two 8mm bolts holding down the timing chain tensioner.
Remove the tensioner, and be careful not to break the gasket!
Dip the camshaft towards the driver side, and pull the
chain from the sprocket SLOWLY. Once the chain is completely off,
IMMEDIATELY hang it!! If you drop it into the case, you will have to
completely remove your engine from the buggy, and take the entire engine
apart to fix it. So hang it right away!!!
Once it is hanging, pull out the old cam! Check the surfaces for scoring
or any obvious damages to the head.
Make sure the surface is clean of any oil and or debris, and now
you can drip some assembly lube onto the mains, as well as into the
bearings of the cam. Drop the cam easily into place, and again, tip it to
attach the chain. It is extremely important that the two small holes line
up again, even with the head... MAKE sure, check and re-check to have the
holes lined up correct...
Once it is in the correct place, lined up and chain on, you may proceed to
install the rocker assembly.
Torque plays an important role here... Factory settings state 25lbs of
torque were used to install these nuts on the rocker assembly. DO NOT
EXCEED THIS!!! Tighten each one in an "X" pattern until snug, then use the
torque wrench to get all of them to 25 ft/lbs, in the "X" pattern.
Once the assembly is back on, re-install your timing chain tensioner. Make
sure the gasket surface is clean, and make sure it rests on the chain as
it slides back into the hole. Tighten them up with the 8mm socket, and now
you can move onto the hard part!!!
Now you need to set your lash. Valve Lash is the amount of travel the
rocker and tappet have before coming in contact with the valve stem. To
set your lash, you will need a feeler gauge set with .003 and .004 gauges:
Starting with the intake valve
(top):
Loosen the adjusting nuts on both the top and bottom (intake and exhaust)
tappets with the 9mm socket and 1/4 inch socket wrench. Once they are
loose, you should be able to spin the square head screw with your fingers
or a very small set of pliers. Place the feeler gauge (.003) between the
tappet and the valve, and tighten the tappet screw until it touches the
gauge. Pull and push the gauge...There should be tugging tension, but not
too tight that it scores the gauge. Once it is taught, tighten the
adjusting nut with the 9mm socket, and re-test the lash with the gauges.
Check and re-check to make sure they did not loosen while you tightened
the nut.
Repeat this step for the exhaust
valve, only, some manufacturers recommend that you use the .004 for the
exhaust valve instead of the .003. I checked my depth BEFORE removing the
rocker assembly, and I found that both were set at .003.
After re-checking 3 times or more for each valve lash, I felt comfortable
with my settings, and now it is time to close up!
Using a small bead of black rtv, I made a new gasket and re-installed the
valve cover:
Now, just re-install the fan, the
plastics, the carb and intake and all other components that were removed,
and you can finally test out the performance!!!
IF you experience hard starting, or a no-start condition, the your timing
is off. If you experience back-firing or constant popping, you may have
been off by a few teeth or even 1 or two on the chain and cam gear. you
will need to go back in and re-set the chain on the cam if this is a
problem you experience. That is why it is sooooooo important to line up
the holes of the cam in the beginning.
If you have a no-start problem, or it back fires but doesn't run, then you
most likely are 180* off, or were on the wring stroke when you set your
timing marks. Again, you will have to remove everything and re-align the
marks and TDC to assure proper timing.
This is not an easy mod, and tuning will need to be stepped up as soon as
this mod is completed. Better intake if not already installed, better
jetting, most likely a larger jet is necessary. New spark plug is
recommended. And exhaust modifications may be necessary to produce the
highest level of performance from your new mod!!!
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Your new cam
is waiting at
KidnMe
Motorsports
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Good luck,
and hope this helps you out if and when you decide to go big!!! |
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How do you re-jet? SIMPLE!!!
#1: shut off fuel supply to carb
at petcock or inline shut off... if you do not have one, drain fuel tank,
or crimp fuel line to keep fuel out of carb...
# 2: unscrew the intake and the
manifold hose clamps on the carb. simply remove the carb from the
manifold (gently) or sometimes you can just twist the carb counter
clockwise to have the bottom facing the passenger side... either way,
this is what you should have: and the manifold left on-- make sure to
clean the area but first put paper towel in the manifold to keep debris
out!
NEXT...you unscrew the screw at
the very bottom of the carb, most of the time found in the center... this
is the "fuel Bowl Drain"..... it will drain out the gasoline left in the
carburetor...so make sure you have a drip pan or catch can under the buggy
to catch the fuel...
NEXT!!! after the dripping
subsides, you simply unscrew the 3-4 screws holing the Fuel Bowl to the
carburator...
Take
special care when removing the bowl, as there is a rubber gasket attached
to seal the carb, and you DO NOT want to break this!!!
The fuel floats are found in here,
and most of the time they are plastic and can break easily, so you do not
want to bang on the carb to loosen the Bowl...
This is what it should look like
with the bowl off:
OK...now you locate the MAIN
JET...This is it:
Simply unscrew this jet with a thin, flat head screwdriver... and install
your new, oversized jet... For my testing, I went from a 128 jet to
137.5...
Now, you carefully line up the
fuel bowl and screws, tighten them evenly, and make sure you tighten the
fuel drain back up...
Then simply re-install the carb
back to it's original position, and tighten all clamps tight...open the
fuel supply back up, let the carb fill for a minute or so, and start your
buggy....
use carb cleaner to spray the
engine while it is running to check for leaks... buggy will bog down or
shut off if you have a leak...
spray one spot at a time, and if
the motor doesn't slow down, you are free to run it and see how it
performs!
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The rollers are located inside that cover on the driver
side of the motor in the buggy... Some covers are black, my cover is
silver... This cover protects a part known as the variator, and the
clutch. The variator and clutch are linked together by a belt.
The rollers are weights which are activated by the speed of the motor...
They roll out from the center, as the speed of the engine increases...
This action forces the variator body to sandwich the belt, in turn,
engaging the belt, then engaging the clutch... As the engine slows down,
the rollers roll back into the center, releasing the belt.
An alternative to rollers, which are sometimes prone to "flat spotting,"
are sliders. While more expensive, sliders are less likely to wear, and
are more reliable over time.
The variator is mounted directly to the engines' crankshaft. This is the
first component of your transmission. It is bolted in place, and consists
of 5 basic parts. The fan, the body, the rollers, the shaft, and the
cover. A large nut, 18mm, holds the variator in place, with a washer
between the fan and the nut-- Most of the time it will require an IMPACT
gun to remove. You can fashion up a jig to hold the variator in place, but
often, this spells tragedy for your fan, which the blades can easily brake
off from.
Remove nut: Then Remove fan and belt:
Hold your fingers behind the variator cover to ensure it does not fall
apart as you pull it from the shaft... You do not want to loose any
pieces, or forget how it goes back!!!
And now you have the variator removed, you can look inside!!
As per parts... I first upgraded my rollers to a smaller weight, then my
entire variator for better air control in the case later on. you will see
pics from the latter of the two, but the concept and the steps are
identical.
I was more in favor of 10 gram rollers initially, however, many dealers
were out of stock, and the Kidinme karts is the official Kidinme karts is
the official dealer for the NORTH EAST GANG! for the NORTH EAST GANG! I
had established a relationship with, had a different set, 9 grams, in
stock and ready for shipment. I decided I wanted those, as opposed to
11's, and that, coupled with a 1500 lb spring, got me off in the right
direction.
The rollers are simply 6 little cylinders coated in graphite with bronze
or brass centers. They roll in and out of their respective slots inside
the variator body... seen here:
The stock ones are the blue, and the 9gram rollers are in my hand. You can
see where they go into the variator, and there are ALWAYS 6!!!
NOW, you just swap out your stock rollers for your new ones, and
re-install everything just as you pulled it out!!! To make life a little
simpler, you can tug the belt as hard as you can, so that it goes deeper
into the clutch (rear pully), and this will give you slack as you
re-assemble the variator back on the crankshaft.... Variator
cover/body/shaft go on first, then the belt onto the variator shaft, then
the- fan/washer/nut- in that order.
Use the impact gun to secure the nut tightly back on the variator after
everything is re-assembled... BUT thread the nut carefully with your hand
first!!!!! YOU never want to cross thread the crankshaft!!!
I upgraded my variator to the MRP vented variator, which included a
lighter alloy variator body, and a vented shaft for the belt...
After installing the your rollers, Start getting ready to install the 1500
lb spring, Both mods will give you exceptional hill climbing
ability, much more top end, and a bit more torque!!!!
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Gutting your exhaust is a cost effective way to improve
performance and give you a little extra power. This will not produce the
same results as installing a quality high performance exhaust system but
it's a good start. This project should only be done after you have
upgraded your air intake, filter and carb.
Tools Used
Common - Wrenchs, Hammers, Vise
Uncommon - Chop Saw with metal cutting wheel, Welder, Dremel, Bench
Grinder
Step 1
Carefully remove the 2 studs located under the engine and the side bolt on
the muffler. If they are to tight do not force them, give them a
good soak with a penetrating solvent first. A broken stud or bolt is
not something you want to waste time on. If a stud spins out completely as
shown in fig 1 do not worry. As long as the threads are not damaged it
will reinstall without any problems. Do not us a bonding agent
to reinstall these studs. This will make it more difficult to remove a
stud in the event one breaks in the future
Step 2
Remove the bolts from the chrome cap and heat shield
Step 3
Inspect all bolts for excessive rust, damage heads and threads. The
high heat causes these pieces to rust much faster then all other nuts and
bolts and replacement may be needed from time to time. In most cases a
good cleaning with a soft wire wheel on a Dremel or bench grinder will do
fine for proper maintenance and longer use.
Step 4
Check the side mount bushing for wear. This item is more important then
you might think. It reduces vibration and noise and is vital in keeping
stress off the main studs. If its damaged, replace it as soon as possible.
Step 5
Prep your muffler for cutting. Clean all loose dirt from the surface
and draw a line from the end cap down on to the muffler body. This
will help you line up the cap after cutting. Use a permanent marker
or sharp tool to make sure the line stays visible until your ready to
weld.
Step 6
You can now begin your cut. Carefully lineup the original weld just past
your cutting blade. You want to cut only the muffler body not the cap. If
you cut the cap it will not seat right and you will not able to reinstall
the chrome cap when the job is complete. It is important to let the
saw make the cut, do not force your blade down with to much pressure. You
can damage the muffler or worse snap the cutting blade. These blades do
break and can cause extreme
injuries so take your time and be careful. Another important thing
to remember is the size of the saw you use will determine if you can make
a straight pass of if you will have to stop and rotate the muffler to
complete the cut. A 10" chop saw is the smallest one you can use for
a straight pass. Some models safety shield are to large and need to
be removed in order for them to cut in one pass.
Step 7
After your cut is made you should have a complete end cap with original
weld still visible around the entire cap. This bead will also help as a
guide when you start your new weld. At this point you will want to
clean all the edges of both cut pieces. On the inside edge you can
pull off any large shaving still attached to the inner edge by hand.
Now using a die grinder or dremel smooth out the inner edge and make sure
no loose metal remains. Small metal fragments left behind will break
away and bounce around inside the muffler producing an annoying rattling
sound similar to a loose bolt on the exhaust.
Step 8
Now you can determine how you want to gut the exhaust. If you have a torch
you can remove all internal components, but it is not necessary with this
type of exhaust. The inner pipe comes straight through and only makes one
loop. By removing just the loop you will get the same results as if
were fully gutted. Load a cutting disc on your Dremel. You may be
limited by choice, some cutting wheels are to large to fit in the location
where you will begin your cut.
Step 9
Insert your cutting wheel as close to the plate where the pipe begins it's
exit. Let your grinder do the cutting. Slowly move across the
loop making sure your cut is deep enough. If your cutting wheel
breaks make sure you remove any pieces that may be stuck in the cut you
already made. You will need about 3 or 4 wheels to make a complete
cut. You can only cut from one side because the loop is close
to one side. You can bend the loop a little as you cut gets deeper,
this will allow you cutting wheel to cut away more metal so the final
break is much easier.
Step 10
When you finished cutting as much metal as possible you will have to
chisel cut the remaining
metal. You can use any number of tools to do this part. However due
to the angle using a hammer on hammer will give you the best leverage for
greater impact and a cleaner cut. You can use a masonry or autobody
hammer as the chisel. Place the narrow end of your
hammer directly into the cut you made with your grinder. Now use a
heavy ball-peen hammer and hit the other hammer you inserted into
the cut. One good hard shot should do the trick. Once you remove the
loop use your cutting wheel to remove the remaining loose metal in the
muffler.
Step 11
Now it's time to prep for welding. Grind down the edges of both the
muffler body and end cap with a slight beveled edge. After this is
complete line up the marks you made in step 5. Clamp the parts
together using a large clamp or vise. When everything is secure tack
weld 1 or 2 spots and double check that the cap is seated correctly
before you complete your weld.
Step 12
  Hang
your new gutted exhaust and get ready to paint. It is best to use a
1700 degree ceramic paint. However a 1200 degree paint will work ok.
Use a primer as well and make sure it's dry before you fire up the engine.
Ceramic paints will cure with the exhaust heat but they must first air dry
before you can cook them. The high quality ceramic paints can be cooked as
soon as they are dry enough to handle. They also cost about 3 times the
amount of the cheaper 1200 degree paint. The best priced 1700 degree
paint that I have seen can be purchased from the Eastwood company.
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Here is your new
exhaust.
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