Hey dixie-I put a 14 tooth on the front of my '77650 Custom and left the back stock at 42 (a brand new one along with new chain) I am very happy with the combination which I understand, gives about 12% better acceleration-all other factors being equal. This is according to an old racer friend of mine that has owned a Harlely/Honda shop for 25 years and he has forgotten more about performance than most will ever learn.
Along with the other mods I did, I am more than happy with my gearing choice and I have also retained a little top end pull for passing on the highway without revving the snot outta the motor.
My advice is go with the 14 and the 42. If this isn't enough low end grunt for you then drop another tooth on the front (front sprockets are a lot cheaper than the bigger rear ones.). Hopefully you will have enough adjustment in your chain to accomodate this mod without having to spring for another chain.
1977 KZ650 Custom. Brought back from the dead after 13 years of neglect. Totally rebuilt from frame up. Wiseco 700 kit. Ported, polished heads. Triple angle valve job. Properly re-jetted rebuilt carbs, Filters, MAC Pipe, Barnett Clutch, Shortened Signal Light Stalks, Sculpted Seat, Painted Speedo/Tach Collars and Brake Calipers, Recessed Licence Plate, Polished Headlight Bucket, Bridgestones, Bead blasted rims, 14 tooth sprocket front, Superbike Bars, Painted 2005 Chrysler Magnum Red with silver and gold stripes. Only 13,000 miles on bike. Runs and looks like new and does it ever jump off the line! Colin Firth-Ontario-Canada
-1977 Kz650 Custom bought new by brother. Now with 810 kit, GPz750 cams, intake valves, Mikuni 29 smoothbores, velocity stacks, Dyna Igntion, MAC pipe and other goodies.
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