|Starting a Bullet
Some ideas from Pete Fletcher
Some people have
all sorts of problems starting their Bullets but it's quite simple really.
I shall assume that fuel and ignition systems are OK as the engine is going to be
difficult to start if these aren't right to start with.
The kickstarter on a bullet engages a pawl (little sprung bit of metal) into the
layshaft kickstart pinion which turns the mainshaft which is connected to the clutch,
primary chain, and so to the crankshaft. In other words if you push down on the
kickstarter the engine goes round.
You only get a limited revolution on the crankshaft per "kick" on the
kickstart lever - typically about two revolutions of the crankshaft which, as it is a 4
stroke engine, is only one compression, one power, one exhaust and one induction stroke.
The wrong way;
It seems "right" to start with the engine on compression (you can stand
on the KS lever and really give it some welly) but this is quite the wrong place to start.
You are wasting a lot of that welly because the engine is unlikely to start on that
compression (it hasn't just had an induction stroke, so is unlikely to have the right fuel
mix in the combustion chamber)
By the time the KS lever reaches the end of it's stroke, the engine is approaching it's
next compression and, just when it needs the momentum to get over the compression and
(hopefully) start, the KS lever is no longer providing any push.
The result is that the engine "bounces back" from compression and either fails
to start or, worse still, backfires.
A backfire is when the fuel in the combustion space
ignites, but pushes the piston down back the way it came. This is bad for
the kickstart mechanism (not to mention your ankle/knee) It also can do
nasty things to your oil pump worm drive gear as it's not designed to go
Some people tweek the throttle as they use the kick starter but this is quite
wrong. The engine will start much easier if you leave the throttle closed (or very slightly open
as some engines prefer)
The right way;
If you start your kick just after TDC (top dead centre) the
engine has almost two revolutions to build up speed and gets to compression while you are
still pushing on the KS lever and so it has a far better chance of starting.
How do you find this "just after TDC point"
Fortunately the Bullet is fitted with a "just after TDC" gauge (it's the
ammeter really, but it does the job nicely)
If you switch on the ignition and press down on the KS lever till you get to compression
the ammeter will show a discharge (because the points are closed)
If you now operate the decompressor lever and press down on the KS lever a little bit more
the ammeter will centralise (because the point have just opened)
The engine is now just after TDC.
In reality you don't need the ammeter after a bit of practice as you will hear the hiss as
the cylinder decompresses into the exhaust port.
Note that if you have the lights on this will also show a discharge on the ammeter and
confuse things. Also bikes with electronic ignition systems don't (I think) show this
deflection on the ammeter.
They shouldn't be called kickstarters really as you don't kick them.
What you want is a good firm swing all the way from the top of the stroke and all
the way to bottom.
My starting drill
- Bike on centre stand
- Pull in clutch lever and swing the KS lever (frees the clutch plates and prevents
that crunch when you engage first gear)
- Switch on petrol tap
- Switch on choke if it's really cold.
- Check the kill switch is on - or is that off?
- Switch on ignition and find "just after compression" as described above.
- Leave the throttle closed (or very
slightly open if your engine likes it that way)
- A good long swing from top to bottom of the KS lever travel.
- The engine starts (well nearly always - if it doesn't start after 3 goes I start
looking for a reason - like fuel/ignition/battery faults)
I can start my 350 using this method even while astride the bike while not on a
stand. (Useful when I stall at lights - yes I do, just occassionally)
Electric start systems
I don't have an electric start, but it seems an unnecessary strain on the system
to operate the starter when the engine is on compression.
If you think about it an engine will tend to stop on compression when you switch off the
ignition and there it will stay until you start it again.
If you find the "just after TDC" point with the KS lever first you'll be doing
the electric start system a favour as it has then two revolutions with no real resistance
to build up momentum before it reaches compression. Another way to ease the strain
on the starter would be to use the decompressor for half a second as you press the button.
Just my opinion but;
It works for me!