need specs for 78 kz k50

ok i have had the bike for a couple of years now its a 78 kz 650 its my baby i had it painted canriy bird yellow and it has 4-2 cobra muflers and shit i had the bike doing 110 and i cut out what do u thank they bike willl do how fast do u thank my kz really will doo and if i put a stage 3 kit will it gave me some ponies i need advice because i wanna keep up whith the big boys if u have ideals i whant the bike to do 140 when im done

I ran my gear ratio's, tire size, rpm's through some kind of excel program someone posted here. With stock 64 hp I could get 116mph. My experience says this is probably true, at 4500 I am doing 58 indicated, so 9000 redline is 116mph. I've had mine to 100 and it is still pulling hard.

If you put more horsepower to it you will go a bit faster. I think getting to 140 will cost a lot of money.

Have fun!:woohoo:

Buy a newer bike, the modifications to make your bike go that fast would be very expensive.

where did u find that exeal porgram can u send me the link orrr info on it

I'll look around and post later if I find it.

Here you go !

www.dropbears.com/u/utilities/gearing.htm

kz550man wrote:

how fast do u thank my kz really will doo and if i put a stage 3 kit will it gave me some ponies i need advice because i wanna keep up whith the big boys if u have ideals i whant the bike to do 140 when im done

Only way a KZ650 is going to do a 140 mph is (1) in your dreams (2) vertically down a mineshaft or (3) with a 100 mph tail wind and a 20 mile run up.

Jetting and exhaust changes are not going to get you the H.P you need to acheive that speed. Big bore kit for a KZ650 + new cams + bigger carbs + 4 into 1 exhaust + hours on a dyno getting it all to work, may get you to a true 125 mph max. After that air resistance / drag on a small engined "naked" bike will be just too much for any higher speeds.

Also, the suspension, handling and brakes will not be anywhere near adequate for even these "modest" speeds.

Sell the KZ650 as is, and buy a new 600cc sports bike.

Post edited by: Murphyau, at: 2005/12/07 20:50

140 mph on a Kz650? Fugetbouttit kz5550man!. You would likely need an 810 big bore kit, nitrous or twin turbo set up to get to that speed as well as changing to a larger (than 16 tooth sprocket) on the primary drive shaft or smaller rear sprocket.) Any way you look at it we are talking some serious pesos here amigo! To bump the 650 from its stock mid 60's h.p. range you would probably need to almost wring double that power from the little motor and it would be on the knife edge of reliability. One bad shift and you might be picking cooling fins out of your thighs.

Personally I have never understood the draw of top speed as this is when something is more likely to break on the bike or an obstacle will appear in front of you on the road. At this speed, few people have the skill or reflexes to handle a crisis. Unless your name is Kenny Roberts, Fast Freddie Spenser of Eddie Lawson, leave the Warp 5 speeds to the experts on the tracks.

For me there is nothing like acceleration as opposed to top speed. The thrill for me in riding my bike is banging it up through the gears and hearing the sweet sound of my Kz running on song to near red line. Of course this is done when there is nobody around including the cops who will be more than happy to take away your licence and issue you a personal (all expense paid-by you) invitation to meet the local traffic judge. Remember...even at 140 mph you still cannot outrun the police radio!

Cheers-Colin Firth-Ontario Canada
'77Kz 650 Custom brought back from the dead after 12 years of neglect. 1000 hours of TLC put into project. Rebuilt everything from frame up. Wiseco 700 kit, ported/polished head, pipe, filters, sprocket, Barnett Clutch-The old girl runs like a scared rabbitt!

I have a 78 KZ650C. Over the last 27 years I have dumped about $3000.00 into the engine alone. 720cc wiseco big bore kit, head work, cams, 4 into 1 pipe, 26mm carbs, pod filters, etc. I even had a turbo on it at one time. I have managed 130 MPH on a good day, this was measured with a CHP radar gun. My speedo indicated 140 MPH, shows how off these old speedos are.
You need to understand and use these old bikes for what they are. They are not race bikes and you WILL NOT beat a modern bike no matter how much money you throw at it.
If you choose to ignor the recomendations here, good luck.

Post edited by: baldy110, at: 2005/12/08 12:15