Idle mixture screw/low speed jet adjustment

[jdupree]

I have a 1992 Mercury 200 HP Offshore. I need to put the idle mixture needle valve back in. There are 2 on each carb. The book says that when you put them back on to screw them in until they are snug, then back out 1 1/2 turn to set the correct adjustment. Does this sound right. I just need to make sure I have the right setting when I put them back on. Thanks.

 

[Laddies]

Re: Idle mixture screw/low speed jet adjustment

That is a basic setting when the engine is returned to the water the mixtures need to be fine tuned.

 

[jdupree]

Re: Idle mixture screw/low speed jet adjustment

Thanks. It also says to screw the needle valve in until it is "lightly seated". Does this mean to screw it in until the spring gets tight, or until the screw will not go any further?

 

[Laddies]

Re: Idle mixture screw/low speed jet adjustment

Till the screw bottoms out with care.

 

[jdupree]

Re: Idle mixture screw/low speed jet adjustment

Well, I screwed the idle mixture screws back in until they stopped and then backed them out 1 1/2 turn on each. Now the motor won't start? It will just turn over but will not fire. I plan to check for spark tonight. The motor ran fine before I removed the needle valves?

I would think even if the idle mixture screws were set wrong the motor would still start? If I have spark what next?

 

[mthieme]

Re: Idle mixture screw/low speed jet adjustment

Yup, it should do something.
Why did you "need to put them back in" in the first place out of curiosity?
Did you rebuild the carbs?

 

[jdupree]

Re: Idle mixture screw/low speed jet adjustment

Motor began idleing a little rougher than usual. Sounded like a low speed jet to me. When I pulled one, found a piece of trash on it. Decided to pull all six and clean the passages.