Kicker or Pusher

[Phenoix]

Now for us newbies, (Well mainly me)
How do the bigger bikes "kick back"
All I've ever needed to kick start was an unknowen 100cc farmbike with no problems.

[NordieBoy]

Now for us newbies, (Well mainly me)
How do the bigger bikes "kick back".

Violently.

Apparantly the kickstart gets to near the bottom of the stroke and the engine catches and sends it back whence it came.
Quickly.
And if your foot is still on it, well it probably won't be for long
Just hope your leg isn't completely extended at the time.

[Ixion]

Techo reason.

Almost all engines actually fire the mixture before the top of the stroke. Rationale is that when the engine is running the inertia of the crank mass will carry the piston over top dead centre before the flame path has fully propogated. If the plug fired at or after TDC the explosion wouldn't complete until the piston was well down the following stroke.

The distributor/magneto/ECU changes the amount of "before TDC" (the advance) depending on revs etc. But, even when starting, normally before TDC.

When kickstarting , if the crank doesn't have enough speed, the compression on a big cylinder can stop the piston as it comes up the cylinder. The when the plug fires the piston is still BEFORE TDC, and the explosion sends it down again BACKWARDS. This of course is carried through to the kickstart lever which is violently forced back up, giving your leg and foot a hell of a bang, even throwing you right off the bike.

Some early singles had manual advance retard, with a lever. It was up to the rider to set it. Very nice it was in some situations (ask any sidecar driver - as good as a second gearbox on a sidevalve). But woe betide you if yu forgot to retard it when starting. Ouch. Oh ouch.

[Phenoix]

I thank the benifator for sharing his wise knowledge

[Motu]

lol... you people are lazzy... I can kick start a 51' BSA B31 on first or second go.... big old 500cc 4-stroke single... much fun. Must admit... I never thought of room problems with a kicker though. Something to think about...

Even my piddly little 230cc 2 stroke dirt bike has an electric start these days,and I love it!

But I started riding when all bikes were kick start - and I used to start my B31 with my hand...and that's with Goldy cams,high comp piston and a big carb.Kick starting was just another of those many lessons involved with learning to ride,and it took quite some time to get it right.Just one more thing to add to all the good advice - follow through with all your weight on the lever,don't take your foot off at the end of the swing or it will slam your leg up into the bars.On a centre stand I've ridden the lever up and down a couple of times - if you stay on the lever with all your body weight you'll never get tossed off,and I'm a small guy who used to start some big bikes.Another trick of mine to counter my lack of weight was to pull myself down with my left hand under the seat.Modern bikes have light flywheels which makes them hard to kickstart,big flywheels will store your energy and take it over compression for you.


Having worked as a lawnmower and hire plant mechanic I would put pull starts in there too,getting a reluctant 18 hp single to pull start took everything you had for that day.

You could do anything you liked with the old BSAs alright Ixion,for Rayza's benifit here is my old 1951 ZB31,with B33 top end in a 1954 A10 frame,and a few years later the same bike with a 1948 M20 motor.The sidevalve motor was always harder to start than any OHV motor I had,dunno why.

[Skyryder]

There is still something macho about kick starts that buttons lack. Just not too sure what it is. Perhaps it's the physical ability of stomping the kick start and the bike just roars into life. (in theory) No whirring of starter motors, no nothing but just the plain old roar of an engine starting up. But when push comes to shove I'll go with my push start anytime.


Skyryder

[froggyfrenchman]

push is good for cold mornings, rest of time i like to kick (ride gb400 with both)