Technical What causes the engine to stall rather than idle?

[smart51]

The last couple of times I've been out, the engine will sometimes stall when coming to a stop instead of idling. Otherwise it runs well. What can cause that?

 

[the hobbler]

The last couple of times I've been out, the engine will sometimes stall when coming to a stop instead of idling. Otherwise it runs well. What can cause that?

A number of things can cause your problem----incorrect idle mixture (or even dirt in the idle jet), incorrect timing (should be 10 deg BTDC at idle) or incorrect tappet settings. Another possible cause is the spacer between the carburettor and the cylinder-head---these are known to warp and allow air in, which will then affect the fuel/air mixture.