Merc 850 Idle adjustment?

[smith411]

A friend of mine has an old 850, '70's vintage ? Serial #371474

The carbs are out of wack. He started messing with it and never counted the turns on the idle screws when he started. I'm afraid he may get to lean and burn a piston. Is this possible without changing jets? Where can I tell him to start?

I had the ignition apart and wound up recrimping all the plug wire terminals. Who new they screwed in? I don't think I was the first there though, it ran a little better, he picked up 400 RPM on the top. Is there anywhere to get the cap and plug wires? Is there a way to replace the rotor? I was told it's part of the Dist. and can't be seperated, true?

Thanks for the help.

[CrayzKirk]

Hi,

Start the idle mixture screws at 1 to 1 1/2 turns out. Advance the idle speed screw to 700-800 rpm. While idling in gear, turn the mixture screws out (ccw), until the affected cylinders start to slow down from being too rich. Slowly turn the screw back in (cw) until it speeds back up. Continue until the cylinders start slowing down again from being too lean. Back out the screw 1/2 to 3/4 turn from that position. Once you set both carbs, set the idle back to 550-600 rpm. It the motor hesitates when you advance the throttle, it is too lean. If it sneezes at idle, it is too lean. Better too rich than too lean.

Kirk

[smith411]

I feel better already that's where I started, but we couldn't get it to stay running in gear. Turns out that the neutral safety switch was shorting out in the control box. That's fixed we'll have to give her another go this weekend.

Thanks again,
Kevin