Carburetor adjustment procedure

The air/fuel mixture screw on a Suzuki VS800 Intruder is typically located on the carburetor. To adjust the air/fuel mixture, you'll need to locate the carburetor and look for a small screw that can be turned.
Keep in mind that the exact location of the screw may vary slightly depending on the model year and specific carburetor version on your VS800 Intruder. Generally, it is located on the bottom or side of the carburetor.
Here are the general steps to locate and adjust the air/fuel mixture screw:
1. Locate the Carburetor: The carburetor is usually positioned on the side or underside of the engine. Follow the intake manifold or air filter housing to find the carburetor.
2. Identify the Air/Fuel Screw: Look for a small screw on the carburetor. This screw is typically flat-headed and may be recessed. It is often located near the bottom of the carburetor.
3.Adjustment: With the engine running at idle, use a screwdriver to turn the air/fuel mixture screw. Turning it clockwise (in) usually leans out the mixture, while turning it counterclockwise (out) enriches the mixture.
4. Listen to the Engine: As you make adjustments, listen to the engine's sound. The goal is to find the point where the engine runs smoothly and the idle is stable.
5. Fine-Tune: Make small adjustments and give the engine a moment to respond before making further changes. It's a process of trial and error to find the optimal setting.
6. Check the Owner's Manual: Refer to your motorcycle's owner's manual for specific guidance on the location and adjustment of the air/fuel mixture screw. The manual will provide information tailored to your bike's make and model.
If you're uncomfortable making these adjustments yourself or if you're unsure about the location of the screw, it's advisable to consult a professional mechanic or refer to the specific service manual for your Suzuki VS800 Intruder.

not important, what's important is that they are absolutely clean, including the four brass high speed jets located in the bottom center portion of the carburetor.

That model engine's carburetors has fixed jets, BUT if the slow speed jets are adjustable, earlier model carburetors have been installed. If so...................

The four adjustable needle valves control the flow of fuel in relation to the set air flow, adjusted as follows (if needed).

(Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)
(J. Reeves)

The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to vibrate out of adjustment.

(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor)

Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns.

Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Adjustment and Tuning of a Chainsaw Carburetor ' Chainsawr

store.chainsawr.com/.../tuning.../1126042-adjustment-and-tuning-of-a-c...

Carburetor Adjustment for Chainsaws Carburetor adjustment is critical on chain saws ... These saws have what is called a "fixed jet" which is set from the factory.

Stihl Chainsaw Carburetor Adjustment - Tune-up Settings

tekindoor.com > MISC

Stihl chainsaw's have three carburetor adjustment screws (LA) Idle Speed screw - This ... When the engine is tested at the factory the carburetor is set to obtain a ...

How to Adjust the Air and Fuel on a Stihl Chainsaw ' Home ...

homeguides.sfgate.com > ... > Adjustable Mortgage Rates

The fuel/air mixture in any gasoline-powered engine is regulated by the carburetor, and the carburetor in a Stihl chainsaw is factory-adjusted to provide the best performance.... You'll find three adjustment screws for the carburetor, usually located under the air filter cover.

Factory carb setting on Craftsman 2.0 or Poulan Micro ' Firewood

Let's focus on adjusting the air/fuel mixture. This adjustment can help balance the fuel-to-air ratio for both cylinders. Here are the steps you can follow:

Idle Screw (Air/Fuel Mix):
The idle screw, also known as the pilot screw, adjusts the air/fuel mixture at idle. It affects the fuel flow from the pilot jets (idle jets) into the carburetors.
Locate the idle screw on your carburetor. It's usually a small black knob near the choke.
Turn the idle screw to achieve the desired idle speed. Listen to how the bike sounds while adjusting it.
Note: Adjusting the idle screw shouldn't significantly affect the mixture setting.

Pilot Screw (Idle Mixture):
The pilot screw (idle mixture screw) fine-tunes the air/fuel mixture from idle rpm up to about 1/8th throttle.
To access the pilot screws, you may need to remove the air box and carb side cover.
The factory default setting for the pilot screws is typically 2.5 turns out.
Carefully screw each one in until it lightly seats closed, and then count the number of turns.
You can adjust the pilot screws to make the mixture richer (more turns out) or leaner (less than 2.5 turns).

Dual Carburetor Sync:
Since your bike has dual carburetors, it's essential to ensure they are synchronized.
Use a vacuum gauge set to synchronize the carbs. Adjust the linkage screw until both throttle butterflies are in the same position for idle2.
Synchronization helps maintain consistent performance between the front and rear cylinders.

Check Rear Cylinder Idle:
If the rear cylinder isn't running correctly at idle, it could be due to a partially plugged idle jet.

Consider cleaning the carburetors if needed. While it can be a bit of work, it's essential for proper performance.
If the issue persists, consult a mechanic or consider opening up the carburetor for a thorough inspection.

Remember to take your time and make gradual adjustments. If you're unsure, consult your bike's service manual or seek professional assistance.

Adjusting the Mixture Screws - VT750DC.com

Carb Cleaning on 03 spirit 750 ' Honda Shadow Forums

Carb Adjustments ' Honda Shadow Forums

You probably just need a carburetor adjustment. At half-choke the engine is getting an overly rich fuel mixture. This is normal procedure during warm up, but after a couple of minutes, a leaner mixture is needed. That is where adjusting the carburetor comes in. It probably has a Zama or Rueiing carburetor. I use small automotive type wire connectors (plastic) and lightly tap them onto the irregular heads of the adjusting screws. These are marke L and H respectively on the carburetor. The L screw is always closest to the engine. Here is how to make the proper adjustments. If this doesn't work then a good cleaning and/or rebuild of the carb will be needed. They periodically need this done at any rate after a couple years or so. Please view this:
http://www.zamacarb.com/tipspage.html

Hi John, this is probably a carburetor adjust issue, but it could be something else like an air leak, plugged air or fuel filters or lines. A possibility could also be venting of the fuel tank. This is usually done by a one way valve in the gas cap. The carburetor itself could be causing this problem, and might need cleaning or a carb kit. Try adjusting the mixture screws that could be the problem. When adjusting needle screws turn 1/8 of a turn at a time. Start by adjusting the low (idle) speed mixture screw 1/8 turn out (counterclockwise) to add more fuel to the mixture (make sure you remember the start position). Start your brush cutter and see what happens. If you have to, do that procedure 4 or 5 times. If not any better, return the screw to it's starting position. You might try turning the screw in (clockwise) a few times and see what happens. For your info (the manufacturers suggest to adjust both the high and low mixture screws 1 turn out from a lightly seated position as a starting point to adjust carb. This is very often just right, but if adjustment is necessary it is usually not by much). If the low speed screw adjust has no results, try the same with the high speed screw. I hope this helps a little bit. Get back to me if you have any questions. All the best and good luck.

The specification calls for 900 rpms for the idle speed when warm for the 1987 Dodge Shadow.

One can adjust this with a screw on the carburetor, if it has one.

If it's fuel injected the idle speed is automatically controlled.

Fast Idle Speed HOLLEY 5220/6520 Fig. 5: Turn the adjusting screw with a screwdriver to raise or lower the fast idle speed — make sure that the adjusting screw is resting against the lowest speed step
NOTE: This procedure is performed while the carburetor is installed on the engine.

1. On 1981–82 cars, disengage the two-way electrical connector at the carburetor (red and tan wires).
2. On all years, disconnect the jumper wire at the radiator fan and install a jumper wire so that the fan runs continuously.
3. On 1983–86 models, pull the PCV valve out of the valve cover and allow it to draw underhood air.
4. Disengage the oxygen sensor system connector located on the left fender shield near the shock tower.
5. Ground the carburetor switch with a jumper wire.
6. Open the throttle slightly and place the adjustment screw on the slowest speed step of the fast idle cam.
7. With the choke fully open, adjust the fast idle speed to comply with the value indicated on the underhood sticker.
8. Return the vehicle to curb idle, then reposition the adjusting screw on the slowest speed step of the fast idle cam to verify fast idle speed. Re-adjust as necessary.
9. Turn the engine OFF, remove the jumper wire and reconnect the fan.
10. Reinstall the PCV valve and remove the tachometer. On 1983–86 models, reattach the oxygen sensor system connector, and remove the jumper wire from the carburetor.

Fast Idle Opening MIKUNI

1. Before adjustment, leave the carburetor alone for approximately one hour at 73°F (23°C).
2. Adjust the fast idle opening by turning the fast idle adjusting screw to the following specified values (drill diameter):
   • 2.6L engines equipped with manual transaxles — 0.028 in.
   • 2.6L engines equipped with automatic transaxles — 0.031 in.

Choke Valve Setting MIKUNI Fig. 6: After tightening the choke cover lockscrews, cut the heads off of lockscrews A (total of 3 screws) and stake the heads of lockscrews B (total of 2 screws) with a blunt punch
NOTE: This procedure need only be performed if the carburetor is disassembled.

1. Fit the strangler spring to the choke lever.
2. Assemble the choke valve, aligning the inscribed line or black painted line on the tooth of the choke pinion with the inscribed line on the cam lever.
3. Temporarily tighten the new lockscrews.
4. Set the choke valve by moving the pinion arm up or down, align a punched mark on the float chamber cover at the center of the three inscribed lines, and secure the pinion arm with the lockscrews.
5. Install the choke cover and tighten the lockscrews.
6. Cut off the heads off of lockscrews A.
7. Stake the heads of lockscrews B using a blunt punch.

Vacuum Kick HOLLEY 5220/6520 NOTE: This procedure is performed while the carburetor is installed on the engine. If the vacuum kick is adjusted to open the choke too far, the engine may stall or idle very roughly just after cold start. If it is adjusted so that the choke does not open enough, there may be black smoke in the exhaust. NOTE: To perform this procedure, you will need a hand held vacuum pump capable of producing at least 15 in. Hg (50.6 kPa) of vacuum. The vacuum kick diaphragm may be damaged if you attempt to retract it manually. You will also need a drill or dowel which has a diameter equivalent to the specification for Vacuum Kick in the Carburetor Specifications Chart.

1. Remove the air cleaner. Open the throttle, close the choke and hold it in the closed position, and then release the throttle to trap the fast idle cam in the choke-closed position.
2. Disconnect the vacuum hose at the choke vacuum kick diaphragm. Connect a vacuum pump and apply 15 in. Hg (50.6 kPa) or more of vacuum.
3. Gently move the choke blade toward the closed position just until play is eliminated from the vacuum kick linkage (so that the vacuum kick is determining choke blade position).
4. Insert the drill or dowel into the gap between the upper edge of the choke blade and the air horn wall, toward the center of the gap. The dowel or drill should just fit into the gap. If necessary, rotate the Allen head screw in the center of the diaphragm housing to create the proper gap and then recheck with the measuring device.
5. Restore all vacuum connections and reinstall the air cleaner.

Try by tightening both setting screws (not too tight as this will damage them) ...just enough to the home position...then backing off 1-1/2 turns on each. Try to start, if does not start, then then back off another 1/4 turn, continue till you can start then once started regulate adjust screws slowly to find a smooth idle.

Okay, let me see if I can help you out...it may not be the jets in the carburetor. Hondas, like most other street bikes, have an idle adjust screw on the carburetor. Most times, you can adjust that screw to get your idle at 1000rpm, which is the norm for idle speed.

The screw is not hard to identify; the easiest way is to first, take the air cleaner and intake off. Then watch the carburetor throttle linkage while you twist the throttle. You will see where the throttle cable connects to the carb and there will be a spring-loaded screw right there. Turning that screw adjusts the static (idle) position of the throttle plate; turn the screw so the plate moves in the same direction the throttle cable pulls it.

I'm willing to bet that adjusting this screw will get your idle back to normal. If it doesn't, come back here and let me know; I will then lead you through a procedure to fix the carburetor. Cheers!