cottoncandyninja wrote:
one other thing i forgot to ask. does anyone have a rough idea what kind of power increase putting that kit on my bike will do to the stock 74 claimed ponies it makes? five hundred hard earned ones is alot for just a ten horse increase, unless my torque goes through the roof? just another question i have to help make me salivate better about what this COULD turn into. the little 3/4 liter bike that could.
Hey CCN - I put the 810 Wiseco kit into my '77Kz650 last season so I have a little experience with this package.
It is definitely more powerful than the stock 650 and the Wiseco 700 kit I had in the previous season. I run premium gas and haven't had a problem with the 10.25 to 1 compression ratio for the 810 pistons I put in the 1980 Kz750 cylinders which were bored out to handle the 810 pistons.
I ported, polished and milled the 650 head 10 thou to clean up the mating surface, put in Gpz 750 intake valves that were trimmed 15 thou, left in the stock 650 exhaust valves and swapped in the hotter Kz750 cams. I recently switched to Mikuni 29 smoothbores that I purchased from Wired George to replace the 28's I had on the bike for the 2006 riding season. The 28's seemed to come up a bit short in hard acceleration runs. I have a MAC pipe, velocity stacks and Dyna ignition/coils.
Power guesses are just that...guesses unless you put the bike on a dyno. With the unscientific seat of the pants assessment, the 810 is a far stronger performer all the way through the powerband. I also changed the front sprocket from the stock 16 tooth down to a 14 tooth and this really helped acceleration off the line. I don't drive on the highway so this combo is nice for 0-75 mph my style.
I think it is reasonable to expect that my combo will run at least as quick as a stock Kz1000 given the 650/810 is a slightly lighter package. I also base this on the view of a fellow Kz1000 owner who said that my 810 pulled a lot harder than his well-tuned 1000 did. I also had some runs up against a slightly modified '82 Kz750 that I easily outran at various speeds.
The bottom line is that if you build it correctly you won't be disappointed and will likely suprise some larger bikes with the 810 punch. Do a search in the archives on the 810 and you will find a lot of good ideas on how to upgrade your 750's performance.
Cheers-Colin Firth-Ontario Canada
1977 Kz 650 Custom - Miss January on the 2007 Kzrider.com calendar.
Post edited by: reborn650, at: 2007/02/05 01:00