94 Kat6: Tank on idle 3-4K tank off fine

[redciv1]

Hello I was curious. I had posted before where when the bike seemed to idle around 3-4k. Well today, after a short 15-20 ride, bike warmed, I decided to take the tank off to look at the carbs. I remember back to when I first bought the bike, the bike I had a motorcycle mechanic come over and the exact thin happened. We took the tank off and the bike idled fine. Understand that we did not have a make shift tank, only using the fuel in the bowls. The minute we put the tank on the high idle was there again. Now, since purchasing in February, I have changed all the cables. So today, once again I take the tank off and start her up and she idles. I was able to go up and down on the idle adjustment screw and actually have an effect. Normallly the screw is not even touching the throttle arm, it idles high so I back the screw out to take that out of the equation.

I took the caps off each carb and found that there is 1 rubber o-ring under the sync cap for carb4, no o-ring for carb3 and carbs 1-2 have an o-ring that looks a hair to small. I know I need to get the right size o-rings, so it's kinda hard to diagnose now, but is it worth "rigging" a tank to see if the bike will idle? BTW, all diaphrams look good with no holes, tears or cracks. And they were also sealed under the cap correctly.

[Kreylyn]

My first thought is the tank physically having an affect on your idle... something pushing down on the throttle cable, something kinking....

To remove this possibility, I would instal the tank but don't bolt it down.. start the bike, lift the tank above it a little... see if there is a change due to tank posistion.

Krey

[redciv1]

Good suggestion. I looked at the carbs and 3-4 and 1-2 are not synched together respectfully with each other. I think I am going to visually synch them again.

[redciv1]

Where are the A/F screws on the carbs? Are they on the bottom where the bowls are. Reason asking is because the previos owner cleaned the carbs and if so then the A/F screws should be visible. I noticed that there are 4 screws on the bottom of each carb. I'm trying to figure out if I need to do the "DRILL" parrt. I want to visually synch the carbs.
Do I adjust the butterflies by moving the A/F screws on each carb? That part was unclear.

[kevin2502000]

The a/f adjust the mixture ratio and have nothing to do with the throttle speed. The synch screws are what you are wanting to turn, there are 3 of them. A/f screws 2.5 out from closed.

[Kreylyn]

Picture of the A/F screw is page 13 of the carbs 101 pdf.

http://katriders.com/vb/showthread.php?t=63344

The A/F screw is part of the pilot circuit, and has no affect on the butterflies. Butterflies are adjusted by the screw that is on the levers between the carb bodies.

Here is another source of info with pics for you as well with similiar carbs...

http://www.gixxer.com/forums/showthread.php?t=159718

Krey

[redciv1]

Thanks for the understanding. You know I consider myself very mechanically inclined, however on cars I don't touch timing belts and bikes, seem to be carbs. I'm trying.

[kevin2502000]

Here is an easy auxillary tank http://katriders.com/vb/showthread.php?t=99740

[ICEG]

it might be the filter being clogged clean it and adjust the af screws

[md86]

it might be the filter being clogged clean it and adjust the af screws

[DumbLuck]

So today, once again I take the tank off and start her up and she idles. I was able to go up and down on the idle adjustment screw and actually have an effect. Normallly the screw is not even touching the throttle arm, it idles high so I back the screw out to take that out of the equation.

sounds like a miss-routed, kinked, or bound up cable from the tank pressing on it.