carb airscrew

[bansheejoel]

when you screw out your airscrews does it make the engine run leaner or richer? Mine are at 2 screws out but i heared 1 1/2 was right. Just want to make sure im not running it to lean by being 2 screws out....thanks

[fun_on_the_sand]

when you screw out your airscrews does it make the engine run leaner or richer? Mine are at 2 screws out but i heared 1 1/2 was right. Just want to make sure im not running it to lean by being 2 screws out....thanks

 

It is call "Air screw" because when you "open" (counter clockwise) lets more air go through making the mixture leaner.

 

Thinking this way makes me remember when I'm adjusting it. I hope it helps you too.

[BellicoseBanshee]

Turning the air screw clockwise reduces the amount of air and turning the air screw counter-clockwise increases the amount of air in the pilot system.

 

Warm up your engine, then adjust the idle slightly higher than normal. Turn the airscrews in until they seat and then back them 1/4 turn and let the engine stabilize. Keep turning the airscrews out a 1/4 turn at a time, allowing the engine time to stabilize between changes, until the engine reaches its highest RPM. The air screws should be between 1 and 2-2.5 turns out. If the highest RPM is less than 1 turn (lean), install a larger pilot jet. If the highest RPM is more than 2-2.5 turns out (rich), install a smaller pilot.

[gregrob]

So the air screws are ONLY for the pilot circuit? Starting and idling?

 

I am rich in the mid range and have the needle on the next to top position, I was gonna play with the screws to see if it would help.

[theshee]

Greg, air screw is only in the pilot circuit... lean out your needle one clip and see if that helps.

[gregrob]

Thanks Kiel.

 

I'll put the clip all the way on the top notch and see if that clears it up.

 

It's just blubbery right before the power comes on in the mid range. Usually when holding the throttle steady. If you gas it, it will clear up and the power will come on.

[theshee]

You should ride a cub... seems like they are never jetted right. No bottom end, seems like they are not right, then the power kicks in and it jerks your arms pretty good!

[gregrob]

That's what I hear. :cool:

[Guest utleybanshee]

You should ride a cub... seems like they are never jetted right. No bottom end, seems like they are not right, then the power kicks in and it jerks your arms pretty good!

 

I JUST GOT A 421 CUB AND THATS EXACTLY HOW IT FEELS..

[Animalman294]

Yep thats about right, I think the damn thing is always jetted wrong, but then I check it and its fine. I do have one gremlin that showed up here recently and the right plug is lean and the left plug is dead on. I think it is a plug wire or coil issue............