Forum

[wilf]

Hi Scalyback, how's this: Ran only yesterday after lubrication. Engine now fires intermittently,erratically, lastly dying.

[simon]

Should Probably Run Again Graunch!

[simon]

Should Probably Run Again Graunch!

[simon]

I didn't post that twice. There is a bug in the system.

[Presto]

No criticism of Scalyback intended. (Maybe I have a problem!)
On the other question - the sprag clutch - can it break if you don't use the 'leccy' starter? I'd say no. It just sits there without any stresses on it. It's like it's not there at all when it's not used. No reason for it to fail when it's not engaged, as it can't then be forced backwards - it's being forced backwards that does the damage.

[PeteF]

Presto, just one decent backfire is all that's required to bugger the sprag.
Even the engine "bouncing" back from TDC when stopping can do damage. That's why lots of people stop the engine with the decomp.

[Presto]

I understood that a sprag bearing is in an 'idle' situation when not engaged by the starter motor. In that position no damage can occur. It can only be damaged when it is spinning and when a backfire etc forces it to rotate in the 'wrong' direction. At other times the kidney shaped bearings make no positive contact between the bearing/gear interface. That's how I have understood them to work.

[Dennis C]

If the engine turns backwards it forces the sprag to engage. It is a bit like the free wheel mechanism on a bicycle, wheel it forwards and the pedals dont move, wheel it backwards and the pedals turn.

[Presto]

Thanks - got it. That's useful. I'm surprised in that case that they don't go even more often!

[Scalyback]

There you go, a classic scaly cock-up.



I meant to stress that mnemonics are the army way of teaching (DDCC Duck, Down, Crawl, Cover), but missed that out!




therefore for the actual letters and words, acronym will do very well!



Bike Utilising Lotsa Low End Torque