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ATV DIRT BIKE SCOOTER TECH TIPS |
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Tech Tip #1--Overflowing ATV Carbs--Gas Leaking |
Solution :
These small carbs on the ATVs have very small needle and seats. The needle
rises up and closes off the gas flow. If there is any kind of dirt, hair,
plastic particle or anything---it will prevent the needle from closing and
gas will run out of the overflow tubes. The normal way to fix this is to
remove the bowl of the carb which usually requires removing the carb and
messing with small parts, BUT there is a shortcut that sometimes work,
sometimes....You open up the bottom drain screw
on the carb and also remove the fuel line from the tank or petcock (shutoff)
and gently use compressed air (low pressure air) and blow through the fuel
line.
Sometimes this will dislodge whatever is keeping the needle from shutting
the
fuel off. Another old timer trick is to gently tap on the carb bowl with
something wooden or rubber or plastic. Then you can hook the system back up
and see if the gas now shuts off. If gas continues to overflow you may
repeat the procedure or the carb may have to be removed for inspection to
find the dirt or why the needle is not shutting off the gas when the float
rises. |
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Tech Tip #2 -- Stumbling Carbs on the 150 and 250 ATV |
You pin the throttle
and it stumbles, dies, stalls. The factory installed carbs are a
constant velocity style or CV for short. This is a very popular carb
nowadays and even comes shipped on several new Harley Models. This CV carb
is touted as being the next best thing to fuel injection. Trick --this carb
needs a restricted air box. Most mechanics want to rip off the air box and
install a free flowing KN style air filter. NOT SO for this CV carb. Don't
do it. This carb has a small venturi, a butterfly like a chainsaw carb, and
a slide that raises up by vacuum. That slide must go up to also raise the
main jet needle and that lets the gas flow to rev the engine. Screw up that
velocity or vacuum and it stumbles and dies.
Solution:
OIL that air filter foam. For one
that helps filter the dirt from going into your engine and it also creates
restriction in the air box. When starting a cold engine you can
squeeze the rubber hose between carb and air filter box to richen the whole
system. Some of these CV Carbs are cold natured and if you are impatient
just reach down and squeeze the hose with left hand and thumb throttle it
with right hand.
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Tech Tip # 3 -- Kazuma 50 Meerkat Carburetor Improvement |
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Perfect tuning of the
Meerkat engine by increasing the fuel. This is performed by unscrewing
the top of the carb and pulling the slide out. You have to remove the slide
from the throttle cable to get at the main jet needle. (Looks like a
needle). You will enrich the air/fuel mixture by raising the needle or
lowering the clip. One notch should do it. Re-assemble and notice the
performance increase and purr of the engine. Also make sure your slide
lines up with the tabs on reassembly to prevent stuck WOT. (wide open
throttle). |
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