1978 KZ650 810cc BIG BORE KIT !!!!

Hello everyone, I have been a member for some time now but dont get much time to get on here. I need some info from all you kzriders out there. I recently purchased a 1978 kz650 sr from a guy. He told me that the bike has the 810cc big bore kit in it but couldn't give me any details of what more has been done to it. From the way he talked he was scared to ride it which made me want to ride it lol. Anyways i noticed that the bike has the 630 chain on it instead of the 530 chain and would like to switch back to the 530 if i can maybe that motor is to powerful for the 530 chain im not sure and they have a 17 tooth on the engine and a 40 tooth sprocket on the back wheel. Is that a good set up for this bike?????. What carbs would be best to run on this engine ? Any help would be very very very appreciated !!!

the only bike i have with a 630chain is the 77 1428 and that damn things got a turbo,im in the process of getting new wheels for 1327 bike and it will have a 530chain conversion also when its done you shouldnt have any problems with a 530chain on that 810!if you change the chain you will have to replace the sprockets to match im going to a 16 and 40 on 1327 should wind out down the highway at about a buck 30 but it will get there really quickly,just depends on what you want to do with it same with carbs a good set of 28-29s are plenty for smaller engines i even know of a very hard running 1105 that runs 28s!:whistle: goodluck,happy wrenching!

Even 500hp+ Hayabusas use 530 chain, 630 chain is for boat anchors and Top Fuel bikes. Less rotating mass means more power to the back wheel too.

My guess is that at least part of your 650 engine came from a 750 engine, which uses the 630 chain and sprockets. I still have the 630 chain on all of my bikes, but if I need to replace a chain I intend to use new 530 sprockets and o-ring or x-ring chain.

The 750 engine cases are nearly identical on the outside to the 650, so using the 750 gear was a direct bolt-on.

Thanks guys for all the info. That is what makes kzrider.com the best place in the world to get help and info when you really need help. I think that i will switch the 630 chain and sprockets back to the 530 that should help on weight issues anyway. I will get me a nice set of 26mm carbs or some 29mm smoothbores im watching on ebay. Where is the cheapest place to buy a set of k&n pod filters? Does anybody know how good the cheap filters work ? I know they dont compare to k&n but would they do the job? Anyone live in kentucky would love to find some kz riders around here to ride with. Here where i live it is eat up with the harley and crusiers everywhere. Ever since orange county choppers and shows like that came out a few years ago everyone and their brothers dog had to go out and buy them a cruiser. If you sit at a red light and watch them take off you can tell they dont know how to ride just following the band wagon...

anybody with a visa card can be a biker now,really scarey!