Suzuki gz 125 stalls when put into first gear

it sounds like the clutch is dragging,either it is not adjusted properly or the clutch friction or metal plates are warped and acting like wave washers.you should have about 2mm of free play at the end of the clutch lever when its not being pulled in.also too thick an oil in the engine in it like 20/50 it should be using 10w 40 semi synthetic oil.does it try to pull forwards with the clutch in slightly when you put it in gear ?

I would look for a linkage problem. Some Suzuki bikes have 2 clamps on the linkage, The second can be seen from under the bike only.

the kick stand safety switch could be bad.check it out

check out your side stand safety switch

The most likely cause is the clutch plates have worn out. You have to consider that these 125s are usually ridden by beginners, this means that they will be revved out in ,at least, the first 3 gears.

Hi,
Check the side stand switch and switch on clutch lever. Both can cause problems. In this case the switch on the clutch lever may well be sticking and the engine is being stopped because the system believes you have started the bike in gear with the clutch engaged. ( Which is obviously not the case)
Cleaning / spraying with WD 40 or similar in the area of the switch may be all that is needed.
Hope this helps
Regards Stan

this often means there is a problem with one of the side stand safety switches, there is one activated by the stand, and some models also have another switch under the clutch lever

The bike has a bent shift fork. The engine will need to be torn completely down to replace the bad fork. Check with a local Suzuki dealer as to the cost an to confirm what I believe the problem to be. I fear the cost will be over $700. Bummer. As to the engine stalling, cleaning he carb will probably fix the problem. Please rate my answer. Thanks.

It may need a good carb cleaning or a new spark plug.

Adjust the clutch cable to allow about 1/4" free play at the end of the clutch handle. Don't put the bike in gear until the rpms are near idle speed. The clutch is working fine if the bike does not lurch forward when going into gear at idle speed. Dirty, gritty oil in the gearbox can make the clutch grab. Consider changing oil if grabbing is the problem. The "crunch" you hear is the slider gear engaging into the driven gear. The higher the engine speed when being put into gear the louder the crunch. The slider gear engaging "dogs" can break. Crunching into gear is hard on the gears.

Post a comment to let me know how you come out on this.