Carbs were cleaned out bike still won't start ok with starting fluid but will not stay running

SOURCE: misfire

Sounds like a bad valve to me.... have you checked the compression? that would be the first step.

SOURCE: rebuilt carbs-starts and idles but wont rev up without choke on

sounds like the main jets are partly pluged, you must remve all brass jets and seats including needle jet and its slide soak in carb cleaner and blow out with compressed air only.. hold up to bright light to verify if all are clean. jim

SOURCE: carbs were removed and cleaned. now starts hard and does not idle

sounds like carbs not cleaned right, oh try changing fuel filter, does fuel pump run constantly. if you cant hear it you can feel it, up behind the ignition. Berrymans B12 fuel additive works wonders. double dose add to gas run bike til hot then let stand overnight, pray a lot and try it again.
here is a free pdf service manual too http://www.carlsalter.com/aaman/Yamaha_VSTAR_650_MAIN_MAN.pdf

http://www.custom-choppers-guide.com/xvs650-bobber-build.html

thats mine

SOURCE: Bike won't stay running

Drain the carburetors. There should be a screw on the lower side of each CARB float bowl. Remove the screw then replace it after the fuel drains. Remove the water trap bowl at the bottom of the petcock, (gas valve). Is there any water or trash in the bowl? Drain a cup of gas from the tank. Is there any water or trash in the cup? Dump it, clean it and re-mount it, (not all bikes have a water trap bowl). Install new stock NGK spark plugs.

Remove the CARBS from the bike.
FOR EACH CARB > Remove the float bowl and clean the entire CARB with a spray CARB cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray into all the little airways and fittings in the CARB. Remove the idle screw and the air screw on the outside throat of the CARB and spray into the screw holes as well.
< < READ CLOSELY > >
Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Put the rest of the CARB back together, clean the air filter and install the CARB. Install an in-line fuel filter. Let the float bowl fill then start the engine.

BALANCE THE CARBS
Turn the throttle screw on the LEFT CARB one half turn inward. Now start the engine and get it warmed up. With the engine running, remove the RIGHT spark plug wire. Adjust the idle speed on the left CARB to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Now turn the throttle screw on the RIGHT CARB one half turn inward. Restart and rev the engine. Next, remove the LEFT spark plug wire. Adjust the idle speed on the right CARB to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

SYNCHRONIZE THE CARBS
Remove the air filter and rubber fittings to allow you to see into the throat of both CARBS. You may need a mirror to see inside. You need to be able to see the slides go up and down when you twist the throttle. Now turn the fitting where the cable goes into each CARB such that there is just a bit of slack in the cable, 1/16" is plenty. Lock ONE of the cable adjusters down tight. All further adjustments will be made on the other CARB.

With the motor turned off twist the throttle very slowly while looking at the slides. Both slides need to begin lifting at the exact same moment. If the slides don't raise at the exact same time then slowly twist the throttle until the locked adjuster slide just barely starts to move. Hold the throttle still and turn the adjuster on the other CARB so that the slide on that CARB just barely starts to move also. Now recheck the slide movement timing. Do this process until the slides on both CARBS begin to raise at the EXACT same moment. Lock down the loose adjuster and re-check the slides.

Turn the idle screw on each CARB EXACTLY ONE HALF turn outward and restart the engine. The engine will be probably be idling very fast. Adjust both the idle screws equally from this point to get to the desired idle speed. Congratulations, you have just balanced and synchronized your CARBS This should fix the problem. One last and VERY IMPORTANT thing, Have a fire extinguisher handy and ready for use any time you work on or with he CARBS.

Please rate this solution. Thanks throttlejock!