just a quick question - which way do i turn the pilot screws to lean out the mixture?

[Guest]

Thanks in advance

[MisterCinders]

Which carbs do you have? Some carbs have 2 pilot screws, others dumb it down to a single screw.

[GelandeStrasse]

I have the type with the round flat tops and an adjustment screw on the top of the intake. . .

[GelandeStrasse]

I guess while I'm here i could also ask how many turns out the screws would be a good start point too. The dynojet kit recommends 2-1/2 but it doesn't like to start in the morning and seems to be too rich - will only start with closed throttle - starts fine for the rest of the day??
TIA
Edit: Doh! Still asleep! I'm running pod filters and stage 3 dynojet

[sedelen]

I'm assuming you have "Mikuni BS CV carbs. If you do they'll look like this.

http://www.ebay.com/itm/suzuki-gs-1000-CARBURETORS-/130724974674?hash=item1e6fd0d052&item=130724974674&pt=Motorcycles_Parts_Accessories&vxp=mtr

And if those are them, then the simple answer is adjust "in" to lean and "out" to richen. But be very careful as those tips have a tendancy to break off should you close the needle. Therefore, if you should close them it's important to observe the "lightly" seated rule, otherwise you may experience some heartache.
Here's a fine tutorial from Ed Ness on CV carbs.

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

[Steve]

I guess while I'm here i could also ask how many turns out the screws would be a good start point too. The dynojet kit recommends 2-1/2 but it doesn't like to start in the morning and seems to be too rich - will only start with closed throttle - starts fine for the rest of the day??
TIA

First of all, you don't have "pilot screws", you have "idle mixture adjustment screws", according to the factory manual.

The Dynojet recommendation is probably pretty close for a starting point, but, like all the rest of us, you WILL have to tweak them a bit.

Now, it also appears that you need to learn the proper starting procedure for a cold engine.
1. Turn petock to PRI if the bike has not been run for a couple of weeks, leave it there for no more than a minute, turn it back to RUN.
2. Engage "choke", somewhere between 1/2 and full.
3. Verify the Engine Stop (kill) switch is in the RUN position.
4. Turn ignition key to ON.
5. Pull clutch lever (unless this has been bypassed).
6. Push starter button.
7. Control engine speed with "choke" control.

Did you notice that NOWHERE did I say "play with the throttle"?

That is because YOU DON'T USE THE THROTTLE TO START THE BIKE.

The reason for that is due to the type of "choke" system on the carbs, which is really an "enrichment system", rather than a traditional choke. It relies on having the throttle completely closed to develop the high vacuum that is necessary for pull gas and air through different passages to provide the richer mixture for starting. If you open the throttle AT ALL, you will destroy the high vacuum and the bike will not start.

Eventually you will find the "sweet spot" in the "choke" control that will let you start the engine without it racing wildly, I like to keep mine between 2000 and 2500 on a cold start.

When the engine is warm, you should be able to simply push the starter button to start the engine. No "choke", no throttle, just turn the key ON and push the starter button.


Oh, yeah, let's answer your question. To lean out the IDLE mixture, you turn the screws IN.

On a stock engine, most carbs will work best between 2 and 2 1/2 turns out, but every engine, even every carb is different. I usually start with them about 3 turns out from lightly seated, then turn them in until the engine speed starts to drop a bit, then back them out about 1/4 turn. Note that not all the screws will be the same number of turns out. On my son's 650 that we just got running, three of the carbs are about 2 to 2 1/4 turns out, but the fourth carb would not smooth out until the screw was out about 4 turns. No problem, that's where it wants to be, that's where we set it.

.

[GelandeStrasse]

Great, thanks for your help guys, I'll try adjustments based on your info and post results
Cheers