Honda XL 600R

I just purchased this 1986 dual purpose bike. It has a kick starting system
and is hard to start...not that hard to kick over but it doesn't seem to
want to "fire up" when I want it to. When it does start it idles perfectly
and the engine sounds great and has lots of power to the wheel when driving.
It just seems that during the kick over phase while attempting to start one
of the elements required for combustion is not there. There is however a
good spark (new plug and wire), lots of good fuel, the fuel switch is in the
on postion, the engine has good compression. I don't think the problem is
occuring with the carburator either since when it actually does start
everything is great. Any ideas as to what may be causing it to not fire up
when i kick it? Also if the battery is bad does that have anything to do
with the actual running condition of the bike or is it just for the lights?

 

I just bought a '74 RD350 and I discovered this week that without a
FULLY charged battery, this bike will not start at all. A guy at work
has an xl600R so I'll ask him about it though.

Have you check your choke cable to make sure your choke opens?
That may make it harder to start

BTW I have next to zero MC experience so this is mostly just amateur
guessing

 

Big single cylinder engines are hard to start because the intake
suction only occurs briefly every other turn of the crankshaft. Owners
of old British singles used to go through a starting "drill" every time
they wanted to go riding. The drill included kicking the engine through
with the ignition switch off until they could feel that the engine was
coming up on the compression stroke, and then they would turn on the
switch and jump on the kick starter lever with all their might...

One very critical item on their starting drill was to turn the idle
speed adjuster screw DOWN and get the throttle slide closed all the way
so the engine could develop more vacuum and suck some fuel out of the
float bowl. Those old primitive carburetors didn't have a choke.
Neither do your carburetors.

So, you need to find out how to adjust the idle speed of BOTH of the
carburetors all the way down to help you start the engine.

Your carburetors do not have actual choke plates from what I can see on
www.partsfish.com...

Instead, they have the typical starting enrichener valves. The
enrichener is a tiny carburetor built into the side of the main carb.
It has its own starter jet in the float bowl, and an air passage goes
around the main throttle slide. The enrichener valve has its own little
tiny throttle valve that opens when you place the "choke" lever in the
ON position or pull the "choke" knob sideways, depending on what
arrangement you have.

If the regular throttle slides are open too much, the starting
enrichener won't
"see" the required amount of vacuum, and it won't suck enough gas out
of the float bowls to start.

So what you can do temporarily is to turn the idle speed of BOTH carbs
all the way down. There should be a way of doing that without screwing
up the carb synchronization or whatever arrangement Honda was trying to
do with that two carburetor setup. Then, when the engine is warmed up,
adjust the idle speed back where it should be.

But there's probably a readon why the previous owner adjusted the
throttle slides too far open. The idle jets were probably getting
plugged up, so he turned the idle speed up.

You can clean out the carbs without disassembling them by putting about
two ounces of Berryman's B-12 Chemtool Choke and Carburetor Cleaner (1)
in a tank of gas and going for a ride. Ride as slow as you can without
impeding traffic in order to make the engine suck fuel through the tiny
idle jets instead of the much larger needle jet. The idle jets should
start cleaning out by the time you've ridden 50 miles are so. You'll
notice that the idle RPM keeps getting faster.

You can buy a 15 ounce can of B-12 at Wal-Mart or any good auto parts
store for about $3.00.

(1) I do not own stock in Berryman's, nor do I get a commission from
promoting it. The stuff just *works* so well to clean out idle jets on
Japanese carburetors I tell everybody who has a starting problem to use
it to clean out their carburetors.

 

i have not actually checked the choke cable...will do that. the battery
on my bike does not hold a charge but i have ordered a new one from
honda. when taking the existing battery out to put it on charge i
noticed a small black matchbox size "thingamajig" with two wires
attached by clips to it. there is however a third wire with a clip that
is not attached to it but looks like it should be. seems that there may
be a clip missing from the "watchamacallit" so the extra wire can not be
attached. i have a clymer repair manual for this bike but can not find
out what the matchbox size thing is. any ideas as to what it may be and
if there are supposed to be three wires attached to it? this question
is not just for you but for anyone reading this. all ideas and
suggestions are really appreciated no matter how amateur you think your
guessing may be. ;-) all are welcome to reply by email at
that is an email i use just for times like this and i use a utility to
filter out spam.

 

thanks for the reply. the starting "drill" is making me realize why
people wear shin guards...i always thought it was to protect the lower
leg from rocks and such but now i am thinking it is to protect the lower
leg from the right footpeg when the foot inevitably slips off the
kickstarter and scrapes the leg off the footpeg. ;-) i guess i have
been softened by years of simply pressing a button to start a bike.


i will try what you suggested by putting the cleaner in the tank and
going for a drive. i will also adjust the idle speed down to see if
that helps. that seems like something i don't want to have to do every
single time i start this bike though. i am hoping the carburetors are
sticking and cleaning them either with the fuel additive or physically
removing them to clean will help...although every single time i hear of
starting problems with older cars or bikes with carbs people always
suggest there may be problems with the carbs and in many of the cases it
is something different causing the problem. i hope the problem is with
the carbs...that would simplify things a bit...and quite frankly i
suspect that the problem may very well be with the carbs this time. the
additive you speak of will be going in the tank.

do you know if a bad battery will cause starting problems on a
kickstarting bike or is it just for the lights? also do you know what
the little matchbook size thing is next to the battery with a couple of
wires coming out of it (as mentioned in the reply to monk)?

 

Hi Rick,
Thumpers can be a -itch to kickstart if they are not tuned just right.
You say its running OK and has good compression so the the first thing
you might check is the expansion chamber baffle, located under the cover on
the left side of the cylinder head. Take off the five screws and check the
aluminum baffle for any rips. If it is damaged, you'll need to replace it.
Ever wonder why that bike is as easy as it is to turn over? Your
kickstarter pulls a cable on its downward stroke which in turn opens one of
the exhaust valves a crack. The escaped gases go into this expansion
chamber which is just large enough to make the engine turn over easily but
still have enough poop to fire. If that baffle is damaged you have no poop.
Check that first and if that looks ok, I would suggest getting the valves
and the auto decompression cable adjusted next. Also, you might try logging
onto www.4strokes.com. It's a terrific forum for anyone who owns a BRP (Big
Red Pig).
-jeff

 

O, buy the way. Don't worry about the battery. That bike will start the
same without one.-jr

 

hey jeff,

thanks for replying. i will take a look to see if i can find the
expansion chamber baffle and see if it needs replacing and if the auto
decompression cable needs adjusting. i will eventually bring this bike
into honda for a check up but am hoping to get it to a point where it
starts faster before i do that...just incase i stall out on the highway
on the way to the dealer. :-( i had a quick look at the website you
suggested and i thank you for letting me know about it. any and all
help is appreciated and a website that may offer information that is
focused specifically on the thumpers may be a great help...although this
forum has been great so far...lots of ideas posted in replys to try.

 

If you need parts like batteries and tires and brake pads and clutch
disks, and chains etc., it's best to stay away from the Honda
$tealer$hip.
You can order just about anything that wears out, except for engine
parts, from online catalogs.

It sounds like the fuse holder. Go to www.partsfish.com and register
and you can get free access to the parts fiche for your machine. On the
WIRE HARNESS IGNITION COIL fiche, item #7 is called "case, fuse
connection". this question

 

Oh, man! That's so dangerous! If the engine backfires, you could break
your thumb! ;-)

Back in the late 1960's, when dirt bikes were running around in every
vacant lot and could be seen climbing every hill, we used to wear
lineman's pole climber to protect our calves. The worst kick starter I
ever saw was on my buddy's Greeves 250cc MX-5. If you put your foot
square on the kick starter pedal and vigorously booted the pedal, you
would hit the right hand foor peg and break your toes. The starting
drill was to put your foot on the pedal at a 45 degree angle and hope
that your foot didn't slip off the pedal and have it hit you in the
calf near your knee, leaving a huge bruise.

Well, if the original problem was dirty idle jets, the B-12 will clean
them out and you won't have to go through that "drill" everytime you
start the engine. Nobody wants to have to go through some ritual
everytime they start their engine, that's for sure.

Looking at the LEFT CRANKCASE COVER GENERATOR fiche at
www.partsfish.com, I see that the XL600R has what appears to be an
ordinary permanent magnet alternator. The stator is item #8. But it
looks like the signal generator pulser coil may be built into the
stator. There's a square thing on the stator, and the lead from the
stator looks like it has two wires coming off of it that may be the
pulser coil output. I don't see a pulser coil on any of the other
fiches.

Now, when you look at the WIRE HARNESS IGNITION COIL fiche, you see
that
item #1 is called "cushion, CDI unit" and item #2 is called "module,
ignition unit".

What the heck is up with that nomenclature, besides bean counting
bureaucracy and inscrutable Asian terminology? What does your Clymer
manual have to say about troubleshooting the ignition system? Is there
supposed to be 12 volts at the positive terminal of the ignition coil
or no voltage, when you have the key on?

Once upon a time, a CDI unit was a "capacitor discharge ignition" unit.
(1)

It had big capacitor like the one in a camera's flash unit and the
capacitor had to charge up to about 200 to 400 volts before it would
send the current to the ignition coil and make one hell of a powerful
spark.

The high voltage supply for the CDI was a transistorized electronic
power supply you could hear the oscillators in a metal box whining at a
very high pitch.

Then Honda started installing CDI ignition systems that had a separate
high voltage winding in the alternator stator. It would put out about
50 to 100 volts and it would go to a little box that Honda called a CDI
box, but it would have a capacitor in it, just some switching
transistors that passed the high voltage to the coil.

At the same time, other manufacturers weren't using any high voltage
generating coil on the stator to provide power to their transistorized
ignition system, they were just using 12 volts from the battery and two
transistors to replace the ignition points.

I suspect that's all Honda is actually doing here. If you have a weak
battery, but it is still putting out some juice, turn the ignition
switch on, and check for 12 volts on the ignition coil positive
terminal. If you have 12 volts there, it's no CDI ignition system, it's
just a transistor ignition system and Honda should get their act
together and quit calling
their transistor ignition systems "CDI" units!

(1) Funny story: I was working for an engineering consulting firm
called
CDI Incorporated. It provided consultants and designers to the
aerospace and electronics industry. But automotive performance
enthusiasts kept calling us, asking for information on our capacitor
discharge ignition systems that they thought we built.

 

To follow on from Krusty's comments, I remember when I had the XR250
running, I would have to go through a similar starting drill to start
the bike. Usually involved a completely closed choke (the XR's and
probably XL's have a butterfly choke valve, it's not shown on the
partsfiche diagrams), half open throttle and a few kicks. The engine
would usually fire once, then i'd open the throttle up halfway, half
throttle and a good kick and it'd fire right up. Being a new bike,
might just be a matter of learning the starting procedure. Also, the
XR's and XL's have an automatic decompression mechanism which opens up
one of the exhaust valves as you kick the starter, but closes it at TDC
(i think). I removed mine, but I've heard that if this gets out of
adjustment, it makes the bike very hard to start.

As for the shin guards, I remember a mate of mine coming to work with a
nice blackend shin... while trying to start with the kick starter, the
engine kicked back, the kick starter got him in the shin. Looked very
painful!

Ben.

 

I turned the auto decompression lever manually to the right (a little
further than was occuring while kicking) and it fired right up. I
didn't adjust the cable yet since after it started I took it for a nice
long ride (offroad and on ;-). When I came home I turned it off and
tried kicking it again without touching the lever and same thing...no
go. I turned the lever to the right and kicked it and again it fired
right up. I had other things to do after I stored it away this evening
so I didn't get an opportunity to make the adjustment with the cable and
try it again but will be doing that tomorrow.

Thanks to everyone for all suggestions. I have printed them and will
keep them for future reference when troubleshooting a similar problem.
Also thanks to the operators of this website for providing a very useful
forum for like minded individuals to access. There are obviously some
very experienced and educated people providing highly useful insight
into problems. I am hoping that the information provided is archived
for a long time so other people can troubleshoot inevitable problems by
conversing with people who have had similar problems or by searching a
database. I am pretty confident that the problem I have had is solved
and I am a very happy camper. Woohoo!

 

Thank you very much for providing insight into the problem. I have the
website www.partsfish.com bookmarked and have registered and will be
checking into it as needed.

As a note of interest I see the tool set listed there for $34.99USD
which is $41.75CAD. At the dealer it retails for $92CAD or $77.10USD.
So yes I think I will be using partsfish in the future.

 

I checked the site for that and it seems to be listed in the section
called "SIDE COVER BATTERY". I am pretty sure it is the part number 9.
That is a "Relay, Turn Signal" and there is nothing wrong with the turn
signals so I guess the "extra wire" may be for something else. I will
look into it more later and post back if I find out if the "extra wire"
goes anywhere. Thanks again. Huge help!