Hi, Anonymous it should be noted that the "AIR FUEL" mixture screw adjustment "ONLY" manages your idle and has no effect on any other circuit also any intake leaks must be repaired before the A/F adjustment procedure can be performed otherwise you will never obtain a proper idle and you will waste a lot of time chasing the impossible. The A/F mixture screw's purpose is to fine tune the fuel charge entering the combustion chamber. The following applies to both 2 and 4 stroke engines:
1. The mixture screw may be sealed at the factory with a Welch Plug please review the following video for removal. https://www.youtube.com/watch?v=wAXcksgvDkM
2. The mixture screw manages a range of 3 complete 360-degree counterclockwise turns from the bottom/closed position.
3. The mixture screw should have a spring and o-ring for tension and sealing integrity.
4. Turn the mixture screw clockwise until it gently bottoms out, this makes the fuel charge very lean and the engine should not idle if it does then the pilot/idle jet is too big and needs to be replaced with the next size smaller.
5. Turn the mixture screw 1 and 1/2 turns counterclockwise to establish a baseline for starting the engine.
6. To fine-tune the idle circuit, adjust the mixture screw 1/4 turn in or out to achieve maximum idle RPM, wait 15 seconds between each adjustment for the idle to settle.
7. Never go past 3 full turns out this will make the fuel charge rich, foul plugs, and produce black smoke out of the exhaust, if the engine RPM keeps increasing past 3 turns the pilot/idle jet is too small and needs to be replaced with the next size larger.
8. After achieving maximum idle back out the mixture screw another 1/8 of a turn then adjust the throttle cable idle stop screw to 950-1050 RPM.
9. This procedure works great on 99% of all engines, for the 1% that demand a more robust throttle response on aftermarket monster fuel delivery systems additional tweaking outside the box may be necessary.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day. https://www.motorcycleforum.com/129-first-bike-new-rider/103239-adjusting-old-honda-carb.html How To Carburetor Idle Pilot Screw Adjustment Honda XR70 Honda XL 125 V1 Shop Manual https://www.partsfish.com/page/oem-parts-for-honda http://kjaer.com/media/839645/Honda-XL125L-LEK-Owner-Manual-.pdf
Hi, Roywillis02 and the usual suspects are:
1. Fouled spark plugs.
2. Severely discharged or a damaged battery should have 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a preliminary reading of 12.5 volts or more but little or zero amperage the battery is faulty and must be replaced, AGM batteries fail in this scenario more so than lead-acid batteries.
3. Check battery terminals for damage or corrosion, check the battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
4. Loose connection at ignition coil or plug between ignition sensor and module.
5. Spark plug cables in bad condition, shorting/leaking, spark plug cable connections loose check for spark leakage in the dark.
6. Faulty ignition coil or electronic control module.
7. Faulty pulse coil.
8. Faulty CKP, CMP, or BAS sensor.
9. Faulty ignition switch.
10. Faulty run/off switch
11. Tilt sensor needs a reset.
12. Security alarm failing to disarm needs reset
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day. HONDA 83 XL 250 NO SPARK How to Check for Spark Honda XL 125 V1 Shop Manual https://www.partsfish.com/page/oem-parts-for-honda Honda XL125L Manual
Hi, Dave if your headlight is not working, only one beam works, keeps burning out, blinking, dim or surges from bright to dim to bright the first thing you need to check is the headlight bulb for damaged filaments then check your light circuit fuse, then check your head light bulb socket ground wire for a clean tight connection, that being said the usual suspects are:
1. Faulty ground or power supply wire to headlight bulb socket.
2. Worn down solder contacts or loose fit of the bulb base in the socket due to vibration.
3. Worn, chafed, or broken wires in the light circuit.
4. Corroded, broken, or loose pins/sockets in wire connectors.
5. Faulty hi/low beam switch.
6. Faulty ignition switch.
7. Fuse is good but no continuity on both sides.
8. Faulty headlight relay.
9. Faulty wiring between battery positive and headlight bulb socket.
10. Weak charging alternator/generator/lighting coil
11. Faulty voltage regulator/rectifier ground or overcharging.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day. HEADLIGHT KEEPS BLOWING 79 Honda XL250S headlight circuit problem Honda XL 125 V1 Shop Manual https://www.partsfish.com/page/oem-parts-for-honda Honda XL125L Manual
Hi, Anonymous engine "BOG" is mainly caused by a rich air and lean fuel condition but it can also be caused by a lean air and rich fuel condition this situation rarely occurs and is only caused by the misinformed weekend warrior that owns a toolbox.
The more you open your throttle the more vacuum you are creating in your carburetor venturi and your intake manifold. When you are operating at higher RPM any unmetered air that leaks into your system can become more obvious.
Unmetered air is air that is getting into your system after the fuel has been delivered. If you have unmetered air getting into your system between the butterfly/slide of the carburetor and the cylinder head this will create a lean condition.
All of the rubber components of the fuel system like vacuum hoses and intake manifold that you mount the carburetor to are made of rubber. If none of these components have been changed they are more than likely highly degraded and probably cracked in places to allow unwanted-unmetered-contaminated air into the combustion chamber. Check all of your vacuum lines and vacuum plugs for carburetor synchronization. The vacuum plugs are in the head just after the rubber intake manifolds. The petcock has a vacuum line as well as part of the emission system.
1. Check the intake manifold for fissures.
2. Ensure the bands used to tighten the manifolds down on the intake are secure and have not bound up the manifold.
3. Make sure air box fittings are not warped and fit completely over the carburetor.
Your airbox is metering air and is the first step in a process of consuming air and fuel. The system requires the resistance of the air filter in order to get the proper vacuum to "SUCK" the fuel out of the float bowl and create the proper venturi effect.
Improper mounting and sealing of the airbox will create a small lean effect. This might seem like no big deal but you are inviting dust and debris in your engine that is doing slow damage by not having proper fitment. Fix it so you know it's not contributing to your issue. Pick the low-hanging fruit first.
Do not go and start adjusting anything at this point. It ran fine before. There is something wrong with the assembly or a component. Do not adjust your floats. Get it back to where it was. The moment you start tweaking everything is the moment you lose OEM settings which are a must-have for fine-tuning and maximum performance.
Fine-tuning your carburetor and multi carb syncing come at the very end following the proper procedure established by the Carburetor Gods.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day. bike wont rev past 5000prm 2004 Honda Shadow Fix Engine Won Rev XR125LK LEK XL125LK 2012 HONDA SERVICE REPAIR MANUAL Download Manuals... $15 http://www.partsfish.com/page/oem-parts-for-honda http://mybikemanuals.com/honda/227