KNOCK KNOCK, WHO’S THERE?
I have a 1986 Honda Fourtrax
200SX. It has started making a knocking sound from the engine, but the
sound stops when I rev it up a lot.
Can you tell me what it is and how
to fix it?
Scotts Mills, OR
Hopefully, your knocking sound
is slap from a loose cam chain,
because it’s the easiest fix. You simply loosen the cam-chain tensioner
bolt, which allows the spring to push
out the tensioner against the chain
more, and then you tighten the bolt
back up. If it’s not that, then it could
be a worn centrifugal clutch, which
can rattle when there’s no load on it.
The worse-case scenario would be a
bad connecting rod to the crankshaft.
However, the knocking sound of a
bad rod usually gets worse as the
LIGHT THE NIGHT
I have a 2012 Polaris 500 H.O. and
am looking for more light at night.
Problem is, I usually carry a tote box
on the front rack, and that greatly
limits me in where I can place any
aftermarket lights. Do you have any
Absolutely, son! That’s why you
wrote Boss! Pure Polaris’ LED headlight kit (#2878542) replaces your
stock headlights exactly. And, they
are considerably brighter than stock.
Note that you will also need the special wiring harness too (#2877910).
With this setup you can now have
your brighter lights, even with a tote
box on the front rack. You can order
them through your dealer.
ATV SUDDEN DEATH SYNDROME
It’s me again with my 1986
Yamaha YFM200. I was riding my
quad like normal, and while downshifting there was suddenly a loud
clunk from the crankcase and the
engine instantly died. It has no compression now whatsoever and will
roll freely even in gear. The battery
is fine, and I went over the wiring
harness like you told me, checking
for loose or corroded connections.
Everything checks out, but I don’t
think my quad’s problem is electrical. What should I do now?
Nope! I don’t think your problem is
electrical, either. Electrical problems
don’t typically go “clunk”! I think you
need to pull the top end and see just
what happened. Could be a holed
piston or a broken rod. Something
serious has happened (read “
expensive”), and you may have to consider
just scrapping it. Sorry, son!
HONDA 450R HEAD-SCRATCHER
I have a 2008 Honda TRX450ER
Special Edition that hasn’t had
any problems for the six years I’ve
owned it. A while back the chain
broke, which busted the stock case
saver and bent the shifter down,
causing the engine case to crack.
I finally replaced the engine case
and took my quad for a ride, and it
ran great. After that first ride I let it
cool down and washed it off with
the hose. Ever since then I haven’t
been able to get the engine to start.
I checked for spark, fuel and electrical connections, and everything
looks good. I can’t figure out why it
won’t start and it’s driving me crazy.
What do you think the problem
Well, son, since you have checked
“everything,” let’s start with the
basics. Remove the spark plug and
place your thumb over the spark-
plug hole. Crank the engine over
and see if the engine compression
blows your thumb off the spark-
plug hole. If it does, then you have
enough compression to create a
combustible mixture to start the
engine. If your thumb wasn’t blown
off, then you have a piston/cylinder
problem. And, you will have to pull
the head and back the piston down
and check for scoring. If found, then
a top-end rebuild is in order. But
assuming your thumb was blown
off, then we look at fuel. Dump some
fuel into the cylinder and replace
the spark plug. Crank it over, and if
it starts and then dies, your problem
is in your fuel system. A complete
carburetor disassembly and clean-
ing is in order. Also, drain some fuel
from the fuel tank and see if there
are any water beads in it. If so, drain
and flush the tank and lines. If on the
other hand your 450R doesn’t even
fire, then your problem is electrical.
All the electrical connections need
to be checked for water or corrosion.
Also, look for broken wires. Beyond
that, son, it’s expensive ignition components that need to be professionally tested. Good luck, because you
may need it.
I have a 2012 Yamaha Grizzly
450 with EPS. I put a Dial-a-Jet on it,
and that made a big difference in
mpg and top-end power. I just got
back from a week of riding in Idaho.
Whenever I stopped for a break,
my quad would be hard to start up
again. Once it started up the engine
would run fine. I have heat-shielded
the gas lines and put a heat mat
under the gas tank to help avoid
vapor lock. I also have a Tusk gas
cap with a one-way check valve,
and one time on the ride when I
unscrewed it, the thing dang near
blew out of my hand. It happens
mostly when I’m riding hard. Not as
much of a problem if I’m riding easy.
Hot or cold days make no difference.
Any ideas? I really like this ATV,
except for the hard starting.
I think your problem is as simple
as removing the one-way check
valve or getting a new stock gas
cap. If the cap blew away from the
tank as you stated, then that means
there is pressure building up inside
the fuel tank. This pressure is caused
by engine heat expanding the fuel
inside. Even though you have the
heat-shielded gas lines and have
installed the heat mat under the gas
tank, you still have a heat problem.
There may not be enough heat
By Winston “Boss” McKannick