By Winston “Boss” McKannick
Which one would fit in the frame
better: a 400EX or a CRF450 dirt bike
motor? Thanks for your help.
The 400EX can fit, but it is a lot of
work. There are major differences
between the 300 and 400EX that must
be accounted for. The 400EX is a dry-sump engine. The swap will require
an external oil tank. Motor mount
positions are completely different.
Nothing just bolts up. The 400EX has
twin exhaust ports with the head pipe
wrapping around a single downtube.
The 300EX’s single exhaust port goes
through a split downtube. Because
the 400EX is taller, the carburetor will
interfere with the airbox and seat.
And finally, the 400EX head may
not fit between frame tubes under
the gas tank because it is physically
larger. All of the above holds true for
the CRF450 swap too. Way too much
motor for the chassis to handle. My
advice is to do an ATC350X swap.
It is relatively easy, because all the
motor mounts line up, except the
upper rear. This conversion has been
done enough times that Powroll
Performance has a special kit, including an exhaust pipe. Contact Powroll
at (541) 923-1290 or tech@powroll.
The battery went dead on my 2003
Honda 400EX, so I bought a new one.
For some reason, the engine running wouldn’t keep the new battery
charged up and it went dead too. I
bought a new stator, and it helped
for about a week, but then the battery
died again, so now I’m wondering if
it’s the CDI box or the rectifier/regula-tor. What do you think the problem
is? Thanks for your time.
Many, before you started purchasing expensive parts; you should have
checked out your EX’s charging system first. Obtain a multi-meter that
contains an amp meter. Disconnect
the positive (+) battery cable. Connect
the multi-meter’s positive lead (red)
to the positive (+) battery cable (red).
Connect the multi-meter’s negative
lead (black) to the positive (+) battery
terminal. Turn on the ignition switch
with your headlights off. Your multi-meter should now show a negative
charge. The next step is important, so
follow the instructions exactly. Hold
the positive battery cable (red) back
onto the positive (+) battery terminal.
Start your EX. Remove the positive
battery cable (red) from the battery.
Don’t let it touch any metal! View
your multi-meter. It should now
indicate a small charge. Bring up
the revs to half throttle. The indi-
cated charge rate should increase.
Switch on the headlights. It should
still indicate a charge. If it doesn’t,
then there are two possibilities, and
neither concerns the battery or the
CDI box. Obtain a shop manual
for your EX, and using your multi-meter’s continuity function, test both
of your stators, then test your regu-lator/rectifier. One or both could be
bad with open circuits. Only testing
with a multi-meter can confirm this.
This is what a shop would do. If
everything tests out okay, then look
at your EX’s wiring or connectors,
because that’s all that is left!
POWER INCREASE FOR 400 4X4
I have a 2002 Suzuki Eiger 400 4x4
that is completely stock. I’d like for it
to have more power without going
to expensive modifications. Could
you please tell me some simple
ways to give my quad a power
increase that don’t cost too much.
Prince Edward Island, Canada
Jason, you need to follow the
tried-and-true steps to increased
performance. Increase the flow
of fresh air going into the quad,
increase the fuel going in, too,
and increase the flow going out.
Start with a K&N filter (#SU-5002)
to increase fresh air into the motor.
Next, install a Dyno-Jet kit (#Q-
309) in your carburetor. This will
increase the fuel into the motor
and eliminate any richness and/
or leanness you may now have.
I can only locate one exhaust for
your Eiger that does not produce
more noise. So, I am recommending the MBRP LFT Utility muffler.
And since you are from the “far
north,” I would suggest you get it
from Rick’s Performance, because
they ship free to most of Canada.
They maintain a large ATV store on
the Canadian eBay site. Their eBay
store is here http://stores
sid=p2047675.l2563, while their
physical store is in Harrow, Ontario:
(519) 738-6888 or e-mail email@example.com. ❏
TOO MUCH NOISE
I was thinking about getting one of
the new UTVs, until I actually went
for rides in them. I was surprised by
how much engine noise and heat
there was by the riders. I would not
buy one for that reason. I was won-
dering if you’ve ever tried using a
type of insulation or something to
make a UTV’s engine noise quieter
to the driver and passenger? Is there
anything that will help?
Sure there is! UTVs rattle and shake
and have harmonic vibrations that
are not dealt with at the manufacturer
level like they are in the automotive
world. If you have an enclosed cab,
the noise can almost make it impossible to carry on a conversation without shouting. Start by removing the
UTV’s cab. Install the Stinger RKX36B
insulating sheets to the underside of
the engine cover, behind the seats
and cover all the cracks where noise
can infiltrate. One of the best places
to purchase the Stinger RKX36B is
on Amazon.com here: http://www.
Bulk-Pack/dp/B001HHP59G. I prefer this sound-deadening product
because it is not asphalt-based. You
will thank me the first hot day. The
asphalt-based sound deadeners stink
on a hot day. The other thing you can
do is wrap the entire exhaust back to
the muffler, but I don’t recommend it.
It can rot a header, crack welds and
can come unwound. Yes, it works to
reduce noise and heat in the cab, but
I don’t like the downsides. Ceramic
coating an exhaust is better, but it
is more expensive and requires the
removal of the exhaust system and
sending it to a coater.
HONDA 300EX ENGINE SWAP
I have a 2002 Honda 300EX, and
I’d like to put a bigger engine in it.
Got a problem with your ATV?
Send your questions to Dirt Wheels
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