Looking for the air fuel mixture screws on carb any help?

a back fire on a bike is usually the cause of timing being out or damaged carburettor ( too much petrol going through ) in the case of the carb you can adust the air screw to see if that helps ( small screw in the side of the carb ) screw it right in and then bring it out 1 and a half turns ,this will get you very close to the right mixture. in the case of timing being out you will need to take the fly wheel off and adjust the stator plate ( turn it to the timing marks ) as a rule its usually . back fire through the exhaust is timing,back fire through the carb is fuel mixture. if you rev it when it starts and it pops through the exhaust the problem is within the fly wheel . if it pops through the carb the problem is with mixture.

Try this replacement adjustment screw for an easier way to adjust the idle air mixture. Also make sure that there is not a restriction in the fuel line.

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to much air when mixing with fuel in carb find air mixtur screw on carb an whale running turn in slowley till it stops backfiring turning the screw in adjusts the air mixing with fuel the screw is useuly located on the side of the carb witch the toub hooked up to put fuel in carb is
or you could re set it by screwing all the way in then screwing out 3 whole turns then whale running turn out til it back fires then turn screw in haf to three quarters of a turn in hope this helps

Sounds like your fuel air mixture is a little rich. Check your plugs, if they are black you are running rich which will cause some of the excess fuel to be burned off in your exhaust. Two common problems with a bikes fuel air mixture is bad plugs, if one does not fire consistently all the time it will leave excess fuel in the combustion chamber. Another would be a clogged air filter keeping the fuel air mixture unbalanced as well.

Lastly if you are able to, you may adjust your air fuel screws on your carb. However most Honda's are stock with Keihin carburetors and these air fuel screws are plugged so you cannot make adjustments without drilling out the plugs.

I would suggest not making any changes until you find out the problem. especially if the bike was running ok prior. Was the bike sitting for the winter? did you use any fuel stabilizer? Change fuel including draining carbs. Check your air intake passages for spider webs, any mouse nests,... check air filter. change your spark plugs , especially if they look black. The condition of the old spark plugs will tell you a lot. Black indicates running too rich. Whitish or next to nothing indicates too lean fuel mixture. Tanish color is perfect. Start with the simple fixes before dropping money into her

What this sounds like is a carb issue. There are screws that are located on the carb that control the air and fuel mixture, if you are getting to much air then it will crank and run only for a minute or two then shut off. Have you tried adjusting it? It can take some time to get it right as each bike engine is going to be slightly different and all adjustments are going to be bike/engine specific. I would recommend adjusting the air and fuel mixture, that will probably work for ya. Hope that this helped.

It sounds rich in fuel, try adjusting the screw of the carbs to make the fuel air mixture optimal.

Your carb probably need going through. I would suspect that it's your accelerator pump has got a few holes in the diaphragm and maybe your slow jet is partially stopped up. If the bike has been sitting for an extended period of time, this is more likely the problem. The air mixture is not adjustable unless you or someone else has removed the "anti-tamper plug" that covers the idle mixture adjustment screw. And, only then if you or someone else has turned the screw. If the fuel air mixture has changed, it's something wrong inside the carb. I'd either take it apart and clean it or get someone else with the proper experience to do it for me.

Good Luck
Steve

carb sync is done using only the carb hard stop adjustment u don't touch the air fuel mixture screw, had this exact same bike had the serive manual am dead sure on this

It seems the carb/s flooding with fuel and thus it dies, try to reset the float pin and get the correct level of the fuel in the float chamber.
Standard procedure for air-mixture screw setting is u take the screw right in slowly taking care not to over tighten it as it may damage the tip of the screw.
Warm up your bike's engine and thn slowly turn anti clockwise the air-mixture screw to about 2 & a half turns and observe the engine's idling.
Before you attempt this setting(air-mixture) its better too, to replace the spark plug and set the gap to the specs of your bike's engine and check and adjust accordingly the valve clearance.
Hope this helps!