Idle Settings
 

Carb. Hp 500's...... What Should They Idle At??? And How Much Does Temperature Change Effect The Idle????

750 rpm's would be ideal out of gear. If they are carb engines, temp, humidity and altitude will impact the idle quality. EFI's should adjust for temp and altitude to some degree.

But........ at what idle can I safely get to before I start to hear and feel a clunking while shifting into gear.. That is not what I want to do.

On my 500 carbs I shot for about 650 in gear, would come up a hundred or so out of gear. Much over 8-900 and you begin to get the clunk, which they say is not good. If your carbs are set right you should be able to get down there and not have the stumble chit when going in/out of gear. The big thing I found with the 500's was to let them warm up good before you leave the dock. Getting the temp up there and settled in before you go makes a world of difference.

Merc had a service bulletin on the HP 500's saying the engines should not idle lower than 750rpm in gear. They were worried about reversion with the Gil Manifolds.

Thanks for all the imput...... will adjust to that accordingly