Do i need new sprockets?

[OnD4R1z3]

Hello everyone, I am currently rebuilding my 92 katana 600. It was sitting for years when I bought it. 5k miles on spedo I hope its right. Here are the pictures of the sprockets. Do I need new ones? They don't look bad to me but I am new to this. If new is suggested what size sprockets should I change to currently they are 14/45 stock
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[92xjunker]

I would say drive sprocket (small) yes. The other is ok but, I would change them as a set anyway.

[41 Redhawk]

I would say drive sprocket (small) yes. The other is ok but, I would change them as a set anyway.

Along with the chain. They should all be replaced as a set.

[OnD4R1z3]

Thank you for the answers. i have the bike torn totally apart and fixing/replacing everything might as well do the chain and sprockets. should I stick with stock 14/45 or go up or down?

[92xjunker]

Depends on what your looking for, more top speed or more low end power. Smaller rear will yield more top speed, less low end grunt. Larger rear yields more low end grunt, less top speed (50 tooth is popular) keep in mind that the chain length will change with the sprocket size.

[OnD4R1z3]

i have been all over the forms. so if i go from 14/45 to 15/50 i will have a 3.7026% increase. if i go to 14/50 its a 11.1077% increase witch i think is to much. i have never taken this on the freeway, because i bought it not working, so i dont know what the stock 14/45 rpm's going 70-75mph freeway are. i still want power on the streets but not to vibrate to all he-double-hockeystick going 75. any suggestions would be appreciated.

[92xjunker]

I wouldn't change the drive sprocket, clearance issues, grinding will need to be done to clear some cover supports. Not what I would call worth it.

[shpielers]

visit http://www.gearingcommander.com enter in your bike/year and it'll tell you what RPMs you'll get for different speeds in different gears. You can enter in any tooth count you want for either sprocket.

If your carbs are well tuned (a/f screws to 2.5 turns out, and synced, and clean) the bike wont vibrate too much. My '06 600 has ~102k miles on it and burns lots of oil...and still vibrates less than my buddy's well maintained 6500 miles on in '09 SV650.

With stock gearing, my 600 was getting somewhere around 5500-5700rpm at legal freeway speed in top gear. At a purely hypothetical 80mph, it may or may not be just over 6000rpm...
Can't imagine a pre kat would differ too greatly from a post kat in this regard.



edit:: was bored and looked it up. at 65mph, with stock gearing, you'd be at 5250 rpm. at 75mph you'd be at 6060rpm.
with a 50t rear and 14t front, at 65mph you'd be 5700rpm (500 higher) and at 75mph you'd be at 6600 (still ~500 higher)