[89suzi]

Just a quick question about the mixture screw on a 89 sierra

When I rebuilt the carb stupid me removed the mixture screw

Just wondering how man turns out from all in for a stock tune? Stock motor everything


Thanks

[89suzi]

Bump bumpbump

[Marko_SJ]

That one is supposed to have a tamper proof on it to stop people from fucking with it?

Screw it all the way in so it seats, then according to the interwebz try 1.5 - 2.5 turns out. Or try all the way in and then wind out till it gets better, then keep winding it out till it gets worse, then back to where its "best".

Hope you haven't got any other issues with the engine, that would make it fun (not)

[Gwagensteve]

The tamper proof screw only adjusts CO% at idle and is for emissions compliance, which is why it's tamper proof.

It has very little effect on the operation of the engine or its idle quality, which is why it's tamper proof.

Steve.

[Marko_SJ]

Gwagensteve wrote:

The tamper proof screw only adjusts CO% at idle and is for emissions compliance, which is why it's tamper proof.

It has very little effect on the operation of the engine or its idle quality, which is why it's tamper proof.

Steve.

Once again shown why I chose this screen name

I'll have a look at my spare one again.

[Marko_SJ]

After looking at the FSM and the spare carb itself, that screw with the tamperproof is indeed definitely the mixture screw for idle.

Obviously adjusting how rich or lean the engine is at idle will affect CO2 emissions.

To the OP, if he's even still checking this thread, download from here:

http://www.suzukiinfo.com, look for sierra and sj413

It gives a procedure, (on page 130) that is similar to the idle tuning of most carbs.

[89suzi]

Ahh thanks yeah I'm still watching ahah

I got a mixture screw from suzi store but it you can't turn it? Got like metal casing around the screw part

[Marko_SJ]

89suzi wrote:

Ahh thanks yeah I'm still watching ahah

I got a mixture screw from suzi store but it you can't turn it? Got like metal casing around the screw part

That link I gave ya will reveal all the secrets of the mixture screw. It is designed to be un-adjustable, except for those with a special tool, who would have been Suzuki dealers or people who adjusted and serviced carbs for a living.

[losfer]

I have the tool . if you wind in the screw it will lean out and die , i normally wind it out till it runs smooth then 1/4 of a turn .

[89suzi]

If your were in Perth I would ask to borrow it ahaha suzi store wants to charge me minimum of 46.50 to put it in....wtf
Legit a 2 sec job

[Marko_SJ]

89suzi wrote:

If your were in Perth I would ask to borrow it ahaha suzi store wants to charge me minimum of 46.50 to put it in....wtf
Legit a 2 sec job

Maybe try order one from somewhere?

[89suzi]

I asked but they had no idea funny enough were you can get it from ahahaha

Any one got any clues?

[Marko_SJ]

89suzi wrote:

I asked but they had no idea funny enough were you can get it from ahahaha

Any one got any clues?

Apparently a suzuki dealership should be able to get it if you have the part number.

Special Tool (Carburetor Adjuster 09918 - 38310)

Or you can apparently cut the cover off with a saw.

[Jas]

bought a motor cycle carby 90 screw driver to do the idle mixture adjustment off ebay, works a treat. also takes 1/4" hex bits so can be used for other stuff.