Air fuel mixture screws

[IcorbenI]

I have a 2003 suzuki katana and have put the Ivans stage one jet kit, and Ivans timing advancement, and a D&D slip on. Now what would be a good start on the air/fuel mixture screws. I was told 4 turns out but i need to make sure that is correct. I also have the morgans carb tune to adjust the carbs but that can be alittle tricky. I just cant seem to get my baby to idle like it should. Any help on this would be great.

Thanks
Bruce

[Black_peter]

Sounds like a question of Arsenic...
But didn't Ivan tell you were to start? I thought Ivan was pretty thorough?

[kidblooper]

Start at 2.5 turns out and ride nekkid.. if no pops your good.. if it pops goto 2.75 ride nekkid etc etc.. never go 4 turns out at 3.75 if its still popping you've got a problem somewhere else.

[Tmod]

Ivan's jet kit suggests 4 turns out but after installing mine I used the colortune on it and came up at 3.75 turns out. Start there as Ivan's kit requires more turns out of the A/F screw than any other kit.

Tmod

[squiggy]

Ivan's jet kit suggests 4 turns out but after installing mine I used the colortune on it and came up at 3.75 turns out. Start there as Ivan's kit requires more turns out of the A/F screw than any other kit.

Just to affirm, Ivans' instruction state four turns to start with, then adjust accordingly.

[hardlydangerous]

Thats because Ivan knows what he talking about.
The idle should be rich.
When your running the bike hard and close the throttle if the pilot circuit is lean or even running stoich it never gives the engine a chance to cool down.
By running it at 4 turns out there is no need to make fule/float level ajustments with his kits so you eliminate the flat spots that the stock set up and most carb kits have around 1/4 throttle. The the slightly rich mixture at idle helps warm the engine uop quicker and cool the engine faster. You can run leaner jetting up top for more power if its slightly richer down low. The last thing you want to do on a race bike or street bike is have a lean pilot circuit. When you are running hard and the temps are hot and you close the throttle if one of the lower circuits are even leaner the at WOT EGTs spike and that can cause detonation. The extra rich mixture also eliminates hot spots in the combustion chambers that can cuase pre-ignition.

Thats just one reason liquid cooled engines put out more power. You can run leaner jetting, advanced timming, and higher compression because the engine temps are regulated by the coolant and thermostat.

[GSXfs600]

Sounds like setting them at 3.5 and calling it good might work for you.

[arsenic]

Sounds like setting them at 3.5 and calling it good might work for you.

did you read the post above your's?

[squiggy]

I should mention as well, he says to use OEM air filter only.

[GSXfs600]

did you read the post above your''s?

Ya, I read it, but four turns is too much. If it needs four turns? then going up a size on the pilots makes more cense to me.

[arsenic]

no, 4 turns is NOT too much.

[Tmod]

When I was talking to Ivan about his specs on the instructions he had stated that you could safely go 5 turns out before the screw will back itself out on it's own. I can only state what worked for me and that may not work for anyone else.

Tmod

[arsenic]

I should mention as well, he says to use OEM air filter only.

and OEM exhaust headers with ANY slip on.

[GSXfs600]

no, 4 turns is NOT too much.

I only believe this because on my carbs, while looking at the needle and inlet hole, it appeared that by 3.5 turns that the needle was completely out of the way! So four or five turns would make no difference over 3.5. Going up a size on the jets and starting at 1.5 turns would make more cense (imo).

[arsenic]

Ivan's jet kit suggests 4 turns out but after installing mine I used the colortune on it and came up at 3.75 turns out. Start there as Ivan's kit requires more turns out of the A/F screw than any other kit.

Tmod

did you use the colortune under load, or just at idle?

I only believe this because on my carbs, while looking at the needle and inlet hole, it appeared that by 3.5 turns that the needle was completely out of the way! So four or five turns would make no difference over 3.5. Going up a size on the jets and starting at 1.5 turns would make more cense (imo).

don't you have a pre 98 Katana?