Kickstart slipping... sprag clutch?

[BultacoBen]

Hello all...

Having got my G2 CSR as close as it's ever been to roadworthy and booked in an MOT for Saturday, my kickstart has just started 'slipping'...

If I push through it slowly then it catches and will turn the engine. But if I give it a stronger kick then it slips and doesn't spin the engine.

Is this a sign the sprag clutch needs some attention? I'm reasonably happy mechanically but have never delved into gearboxes or clutches before.

Many thanks for any advice you can offer!

[REW]

Sure the clutch isn't slipping? No sprag clutch in these bikes.

[borrop01]

Has the kickstart boss on the pedal closed up solid and is not allowing the tightening bolt to close and grip the serrated kick start shaft.
A hacksaw with two blades fitted will open the slot, allowing the boss to grip the shaft when tightened.
Peter

[Rob Harknett]

Sounds like a clutch that has not been used for ages. Check it out. May only need a good clean with petrol

[clanger9]

Yes, as Rob says just check, clean and adjust the clutch. The workshop manual is a bit unclear on Lightweight clutches, but you'll find loads of good information on this forum.

Good luck!

[Janet]

Sure the clutch isn't slipping?

Sounds likely to me. The only other thing I could think of would be if the spring that pushes the kickstart ratchet wasn't working properly and the teeth were worn so it didn't always connect with its mate, but that seems very unlikely to me.

No sprag clutch in these bikes.

What's a sprag clutch?

[Rob Harknett]

I have experienced slip on two of my lightweights, giving them a few kicks holding the clutch lever in has helped stop slip to get them started. Then after a run, no slip. Until left again for a while without being started. One bike needing more than the other. I guess the plates rub a bit kicking the bike over with the clutch lever in. Just enough to clean them up a bit.

[Expat]

[/quote]What's a sprag clutch?[/quote]

Hi Janet,
As no one else has come forward , one answer in my experience with such things would be, it's a 'clutch' that only transmits drive in one direction i.e. either clockwise or counter clockwise and free wheels in the opposite direction. The elements within the mechanism are called 'sprags', hence the name .

Others may have different explanations of course

Steve

[Janet]

Thank you, Steve.
Have I understood this correctly? In simple terms then, it works to give the effect of a ratchet, and like the rear wheel on a standard bicycle where it drives when you pedal forward but free wheels if you stop pedalling.

Every day's a school day.

[clanger9]

Spot on, Janet.

Here's a nice explanation from Wikipedia: https://en.m.wikipedia.org/wiki/Sprag_clutch
They used to use them in 2-stroke cars so the engine disengaged on the overrun.