air cleaner side. Mixture screws are
located on the engine side of the
slide. 2. I will not tell you what the
mixture screw setting should be. I
want your engine to tell you. Listen
and it will tell you what it wants and
what it doesn’t like. Kind of like a
cat! With your engine warm and the
idle speed set, accelerate in third
and back off and decelerate. If your
EX backfires, open the mixture screw
¼ turn more and retest. Reset the
idle speed as necessary. However, if
you reach about 3 1⁄ 2 turns out and it
still backfires, then it’s time for the
next size pilot jet and start all over
again at 2 1⁄ 4 turns out. As far as your
slide cutaway, jet needle and main
jet settings, you may be lean, or not?
You didn’t give me any indications
as to what your EX is doing at what
throttle position. Remember, it’s throttle position, not gear position,
ground speed or rpm.
My wife has a 2005 Sportsman 700
with 500 miles and 40 hours on it.
While parked in the garage I keep a
battery tender hooked up to the battery it came with. We’ve had no
problems until a ride recently. After
30 minutes on the trail, the engine
acted like it was starving for gas.
She would pin the throttle, but the
quad would bog down and eventually stop. It would then start right
back up as good as new. This happened about five times during the
day, and I’m not sure where to start.
Your wisdom would be greatly
First off, Ozzie, I am surprised the
OEM battery can still turn the
Sportsman over after eight years!
Your problem is either fuel- or heat-
related. Both can act the same.
Either you have a fuel-flow problem
and you are emptying the float bowl
of fuel due to reduced fuel flow. The
next time the quad stops, immediate-
ly remove the fuel cap. If you hear a
rush of air inside, then your cap’s
vent is plugged. Next, try the float-
bowl drain screw. If you don’t get a
full flow of fuel, then you are not get-
ting fuel from the tank to the carb. It
could be the fuel filter, a kinked fuel
hose, a plugged fuel hose or the
float is sticking shut. If nothing pans
out fuel-wise, then the problem may
well be heat-related. Could be the
spark plug, coil or CDI that shuts
down when it gets hot. As the com-
ponent cools off, it will start working
again. Swapping parts from another
identical 700 is the easiest way to
find a heat-related component fail-
ure. Good luck!
RAPTOR 700 FUEL PROGRAMMER
Do I have to get a new fuel program-
On my 2011 Raptor 700, I recently
replaced the spark arrestor with an
aftermarket exhaust tip. I was won-
dering if the EFI can compensate for
this minor change, or is there a way
to adjust it? When I take off with the
engine cold, it will sometimes stall out.
mer or am I overthinking this? Thanks.
Well, Cody, I talked to the people
at CFM Performance because I am
assuming you purchased it there or
a similar unit for your 700, and they
state the EFI can compensate just
fine. What you should be aware of is
any engine can stall out if you give it
too much throttle too fast when cold.
Since you did not state the problem
exists when the engine is warm, I
can assume it runs okay then. It is
more important to have the 700 “
carburet” correctly at operating temperature than during the warm-up period, where you should be letting the
engine warm up gently. ;
By Winston “Boss” McKannick
KYMCO MINI MODS?
I bought my son a 2013 Kymco 90R
for Christmas last year, and he loves
it. We’ve had no problems, except
that it’s rather slow. Top speed is
around 12 mph, and he’d like it to go
faster than that. Is there anything we
can do to make it faster? Does it
have any kind of speed governors in
the clutch, carb or ignition? Your
help would be greatly appreciated.
First, check the thumb throttle.
Loosen the limiting screw and, with
the air cleaner removed, make sure
the carb’s slide raises all the way
when the thumb throttle is wide
open. The Mongoose 90s came from
the factory with a speed limiter
spacer in the CVT transmission. This
spacer prevents the front sheave
from closing up all the way, which
then prevents the drive belt from riding up the side of the sheave as far
as it can go. This action keeps the
“transmission” in a lower gear and is
an effective way to slow down a
kid’s quad without resorting to
engine restrictors. You will need to
remove the side cover to gain access
to the CVT and remove the drive
belt. If you now look down inside the
front sheave, you will see the spacer.
Disassemble the front sheave and
remove the spacer. Re-assemble in
the same order as disassembly and
your son’s 90R will be considerably
faster. These mods should provide a
bit more excitement for your son.
400EX GETS BIG AIR
I have a 2008 Honda 400EX.
Recently, I drilled holes in the airbox
and mounted 11 Uni Filter airbox
vents. I’m not sure what the carburetor’s air-mixture screw setting should
be now. Some say it’s suppose to be
2 1⁄ 4 turns out from snug. That doesn’t
seem to be right, though, because
the engine runs like it’s not getting
enough air. Could you please tell me
what the air-mixture screw should
be set at and if any other jetting
changes are needed. Thanks.
Jim, my boy, two things: 1. That
Got a problem with your ATV? Send
screw is not an air screw. Air screws
are located behind the slide on the
your questions to Dirt Wheels “Dialed
In,” P.O. Box 957, Valencia, CA 91380-
9057. Our e-mail address is dwdi-
firstname.lastname@example.org, and include
your name, city and state address.