Mess with Idle Screw ?

Eggman · Post by **Eggman** » Tue Mar 17, 2015 1:50 pm

I'm rebuilding my carbs now. Should I mess with the idle screw? I'm not having any idle problems but thought about doing this as I'm in there anyways. I drilled and popped out the EPA plugs. All my idle screws are sitting at different positions from the factory and I'm not sure if I should sync them or not.

Also I've read some tutorials that say back out the idle screw 3 or 2 or 2.5 turns. But the Mikuni manual says anywhere from 1/4 to 3 turns is ok.

Post by **DonTZ125** » Tue Mar 17, 2015 4:14 pm

There's the idle screw (big honking thumbwheel that physically opens / closes the butterflies) and the idle MIX screws, that adjust the mixture of going into the carbs at the bottom end; these are also referred to as the pilot screws. I've read horror stories here about the pilot screws being utterly out of whack, with one screw in a bank one turn out and another 4 turns out, and everything in between.

Set them at 3 turns; once the bike is up to temp (idling and fully off the starter jets), use a temperature gun to balance the exhaust header temps using the pilot screws.

dans92fzr600r · Post by **dans92fzr600r** » Wed Mar 18, 2015 10:49 am

Hahaha. DonTZ125 had just explained this whole process to me within the past couple days. I havnt gotten that far quite yet.

Eggman · Post by **Eggman** » Sun Mar 22, 2015 3:42 pm

DonTZ125 wrote:There's the idle screw (big honking thumbwheel that physically opens / closes the butterflies) and the idle MIX screws, that adjust the mixture of going into the carbs at the bottom end; these are also referred to as the pilot screws. I've read horror stories here about the pilot screws being utterly out of whack, with one screw in a bank one turn out and another 4 turns out, and everything in between.

Set them at 3 turns; once the bike is up to temp (idling and fully off the starter jets), use a temperature gun to balance the exhaust header temps using the pilot screws.

how do you guys adjust it with the motor running? the only way I can is with the tank removed.

greasemeup · Post by **greasemeup** » Sun Mar 22, 2015 7:12 pm

Auxiliary tanks are about $20. If that's helpful.

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Eggman · Post by **Eggman** » Tue Mar 24, 2015 1:28 pm

So I bought a infrared thermometer and can't seem to get the temps synced. I'm getting...

1 - 400° (pilot screw all the way out)
2 - 200° (pilot screw all the way in)
3 - 200° (pilot screw all the way in)
4 - 400° (pilot screw all the way out)

Any reason the outer cyclinders run so hot?

Post by **ragedigital** » Tue Mar 24, 2015 11:23 pm

Eggman wrote:how do you guys adjust it with the motor running? the only way I can is with the tank removed.

I always just set my fuel tank on a stool next to the bike when adjusting the Idle Mixture Screws.

I hope you're turning the correct screws ::

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