Carb adjustment screw idle

SOURCE: yam ybr125 wont idle off choke,also cannot find idle control scre

you may need to replace your spark plugs

as the idle should remain constant as long as the tune of the bike is good IE oil changes done regularly / plugs cleaned and or gapped , air filter cleaned or replaced all of these can affect your bike.

hope this helps

SOURCE: What tipe MOTOR oil use yamaha 750 FZ, 1987 YEAR

a good 10w40 oil..if you dont know what type was used before then i would flush the engine then put the new oil in

SOURCE: needle n seat adjustment yamaha virago 920

Hello dnjvp...The Hitachi HSC 40mm carbs on the 920 can be jetted and modded as needed to give you the right mixture for any engine or exhaust modifications.
Here is the breakdown for the slide and the internal parts. Check the needle for wear, clean all parts and put back together. Make sure you hold the diaphragm up to the light and check for pinholes. If any are found use a sealer like to fix.


Good luck...i hope this helps.

SOURCE: hi i have a yamaha fz 750 1987. there is no srark

its possible the cdi unit has failed or the hd leads/spark caps might be at fault, i had the same problem on a 1990 zzr600 it turned out to be spark caps where ao to high a resistance and causing no spark to pass. try this first and if still no spark id go with another cdi unit. hope this helps

SOURCE: 95' Yahama Virago 535 XVG.

Look on the side of the carb ,you will find a model number eg keihin cvk30. use this number when ordering replacement carb from the breakers. you will need two identical carbs preferably the same as anything elce will need a lot of setting up and your motor isnt worth tuning with bigger carbs as you will loose out on low end grunt.