April 8, 200917 yr Hi guy's, I seem to be firing the questions out lately any way as I've said in other posts i'm doing some regular maintenance on the bike and i found the plug looked black and sooty, i cleaned the plug when i first got her a while back and this is the first time I've whipped the plug out for a look. What i would like to know is what way do i turn the air screw in and how far each time. I presume screwing it in will lean her off a bit? and how far do i go at a time, 1/4 turn 1/2 turn etc etc would a few hrs riding be long enough to see what she's doing or would you need to ride for a weekend then check? Cheers Steve
April 9, 200917 yr If you have a air screw - out = more air = leaner. If you have a fuel screw - out = more gas = richer. Most delortto carbs on the GG's use a fuel screw. Regardless, You can tell its a fuel screw as its located on the reed block side of the slide. An air screw, as used on the Keihins are on the airbox side. You should definately be able to resolve 1/2 turn of difference on the adjustment, and 1/4 turn when you get a feel for it.
April 9, 200917 yr Author Hi Laser1, Thats what i was looking for. Thanks for that i'll try a few tweeks this weekend. Cheers Steve
April 9, 200917 yr If you have a air screw - out = more air = leaner. If you have a fuel screw - out = more gas = richer. Most delortto carbs on the GG's use a fuel screw. Regardless, You can tell its a fuel screw as its located on the reed block side of the slide. An air screw, as used on the Keihins are on the airbox side. You should definately be able to resolve 1/2 turn of difference on the adjustment, and 1/4 turn when you get a feel for it. Hi Laser1, do you know what the standard factory settings would be for the fuel screw on the Delortto? thanks in advance
April 10, 200917 yr 3 to 3 1/2 turns out on the fuel screw is common in the USA near sealevel - but will depend on the pilot jet size. We tend to run a richer pilot here than you will need in the UK (gas is different is what I was told) FWIW:You should tune the air screw according to performance, not a set number. Warm up the bike to normal op temp. Make sure your idle speed is set to a fairly low rpm, but the bike doesnt stall. Grab a huge handfull of throttle and quickly wack it open to full throttle (twist as quick as you can and release). When the air screw is too lean (too much air) , the bike will bog before reving up. You will want to richen(turn in) the air screw (less air) untill the bog goes away and the bike revs quickly w/o hesitation/bogging. If you make it too rich, (go too far) the bike will start to burble and wont rev as quick. Too rich isnt as obvious as too lean. I usually find it easiest to start on the lean side with an obvious bog, when you can just make out a very slight bog still, about another 1/2 turn will probably get you pretty close. This is a relative thing though. You should try and develop a good ear for this, as most bikes like to be optimized according to temp/humidity/track ect - Note: above procedure was written for bike with air screw - fuel screw will adj in the opposite manner. Edited April 10, 200917 yr by laser1
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