750 C2 fuel/air mixture screw

[Mikeyc99]

Does anyone know where the fuel/air mixture screw is on the 750 c2? I pulled of the air cleaner housing and see an exposed screw, but i thought i would have to drill out the plug first????

[ShadowMonster]

No plug, it's a D shaped screw on the underside of the carb right in the middle, a bit awkward to get at actually and you'll need either the correct tool or a small screw driver and small hands to turn it.

[Marzipan]

Originally Posted by ShadowMonster

No plug, it's a D shaped screw on the underside of the carb right in the middle, a bit awkward to get at actually and you'll need either the correct tool or a small screw driver and small hands to turn it.

... to continue this old thread ... I have just attempted to adjust the A/F screw on my 2001 600 VLX by the procedures in the manual.

Unless you have the $100 Honda special tool it seems impossible. I made four drivers out of .22 casings but found I had little feel for the position of the screw.

Next I bought a stubby D-driver on eBay. That worked after I shaved down the outside diameter but still tended to jam.

Next I took off the carb - seat, tank, air intake, coolant - and turned the screw to 3 turns out as the starting point.

The problem that defeated the proper process is that it is too hot between the cylinders to fiddle with an inadequate tool. (You have to fine tune the screw whilst reading a tachometer.)

So now I have it set at 2-1/2 turns out and will monitor the performance and readjust.

Does anyone know what the factory setting is for the A/F screw on the 600cc engine?

[old dad]

from the 1997-2006 service manual (hard copy I have) for the VLX

Initial Opening
49 state/Canada type ('99-03):3 turns out
(04-05):2 1/8 turns out
California type (99-03): 2 3/4 turns out

on 2006 49 state/Canada type 1 3/4 turns out
California 04-05 2 1/4 turns out,,2006 1 3/4 turns out

I found the .22 casing will fit into a flexible drill shaft I had laying around, slide the fitted .22 on the "D" knob with one hand, turn the end of the shaft with the other,, I had to do an adjustment with my cobra pipes(now gone) but with the stock pipes back on with the holey order mod all is good. Hope this helps ya

[Marzipan]

These bikes may come to the show room with the A/F screw set to a factory default rather than being individually tuned. Does anyone know hat this setting is?

Alternatively, for you who went through the service manual procedure what was the screw final position?

[93gc40]

Originally Posted by Marzipan

These bikes may come to the show room with the A/F screw set to a factory default rather than being individually tuned. Does anyone know hat this setting is?

Alternatively, for you who went through the service manual procedure what was the screw final position?

You really don't want to try to set your carbs based on the results of others. The correct setting for you, condisering elevation and weather, may be way different than what someone in say Florida would need. Start with the factory default starting point and tune from there.
The factory settings are for elevations of SEA Level to about 5000' elevation. Stock, If you are higher than 5000', you'll start at 1/2 turned-in from factory setting.

[old dad]

Originally Posted by Marzipan

These bikes may come to the show room with the A/F screw set to a factory default rather than being individually tuned. Does anyone know hat this setting is?

Alternatively, for you who went through the service manual procedure what was the screw final position?

book stated to start at points I gave previously, while appropriate tach's, whatever are in place, adjust as needed also using the throttle stop control knob to get to : idle speed 1,200 = 100 rpm adjusting until you reach an idle speed of 50 rpm,,
confused, I am. I only adjusted mine enough to get rid of popping on decel, which I did achieve. I had no tach

[Marzipan]

Originally Posted by 93gc40

You really don't want to try to set your carbs based on the results of others. The correct setting for you, condisering elevation and weather, may be way different than what someone in say Florida would need. Start with the factory default starting point and tune from there.
The factory settings are for elevations of SEA Level to about 5000' elevation. Stock, If you are higher than 5000', you'll start at 1/2 turned-in from factory setting.

I would like to achieve that ideal set point, too ... but that takes a fine tuning with good tools. I'm sitting at 2-1/2 turns out after a clumsy attempt at the proper procedure. (Btw for tachometer I used a contact instrument held on the crank shaft via the left side inspection port.)

It would be nice to know if I'm in the ball park based on the results of others who have done it properly.

I'm riding at 2,500 feet. Honda does not consider this elevation to warrant tampering with their setting. I'd be happy to know their factory setting.