Picture of Suzuki JR50 gear mod
The Suzuki JR50 has a hidden lower gear but you have to grind away to find it. Recently I purchased an used 2002 Suzuki JR50 from my buddy since his kids outgrew it many years ago. This will be my girls first bike and we have gone through it to make sure it's ready for their first adventure. I did the first test rides in the yard to get the jetting close but I'm a big man on a very little bike (the girls enjoyed it). One thing I noticed was that this bike is pretty fast so before our camping trip I made sure the throttle stop was in good shape. The camping trip came and I had some seasoned kid riders do a little shake down. Still too fast for my girls so I had the throttle stop almost all the way in crippling the bike to barely run. I opened the throttle a little more to keep it running and the girls had a great time but it was still faster than I felt comfortable with. So I did some research and found that there is a hidden gear inside this motorcycle a low gear. Many talked about it and even explained how to get this gear to work but the forums had no pictures or step by step instructions. I am going to do this mod and document it here since this site should work for many many years.

For this you will need:
A Grinder
Clutch cover gasket
Round gasket
Jesse_19823 months ago
I'm thinking of doing this to my jr50 and was just wondering if it might be easier if I were to drill it instead of grinding?
urbanmx (author)  Jesse_19822 months ago

I don't think it would be easier, you are trying to make a rectangle instead of a square.

petercd1 year ago
Just curious why you didnt pull off the lever to grind it on the bench instead of grinding in the motor?
urbanmx (author)  petercd1 year ago
Skill level mainly plus you need to try it as you grind.
okay, thought maybe some pressed on business. I'll probably never need to do it myself but nice to see the operation, thanks.