Inconsistent idle

[emmotto]

1969 Series IIa 88 w/ 2.25 petrol 4 banger

When cold, she starts right up (with choke) and once choke is off settles down to a nice, even idle. I don't have a tachometer so I don't know how fast but from the perspective of my ears, it sounds just right. Things sound nice and quiet - a bit of clicky clacky but nothing alarming etc. Sounds like a sweet engine.

When warm it idles much higher - I'd guess at 200-300 rpm higher - and is much noisier (more CLICKY more CLACKY).

It's a Weber 34ICH carb and oil bath air cleaner. No apparent air or vacumn leaks that stand out.

Any thoughts?

Mike

[I Leak Oil]

With the engine at operating temp. adjust the carb(mixture and idle) and check the timing. See where you're at then.

[gudjeon]

Make sure you are running the correct viscosity oil in the engine. Common 10w's are too thin when its warm and can be clattery-sounding once the motor is warmed up. Also, lighter weight oils thin out a lot once the motor is warm.

[east high]

You could have a loose or worn mixture screw. Stays in place when things are cool, then things get warm and start expanding... next thing you know you have a screw that's worked itself into a new position. It could also be the Webber warp I've read about.