Griff 500 misfire, pop at idle and fluttering

[Rooty]

Can anyone here help? The Griff has been sitting for c.12 weeks and upon starting today has developed a misfire at idle and under acceleration, popping at idle and a strange fluttering noise under acceleration.

Any ideas?

Many thanks

[wild rover]

Fouled spark plug. Dampness in the distributor cap. Check engine running in the dark. Pulling all the plugs gives you a good idea where to start.
Best of luck

[Loyly]

It sounds like a spark issue so I'd pull the plugs first and check those. Fouling will lead to an intermittent spark which will cause the misfire. The pop is probably accumulated unburnt fuel being pushed into the exhaust and flashing off.

If you can't solve it yourself, a good garage should be able to get to the bottom of it.

[Rooty]

Many thanks