1000J performance curiosity's

modprod wrote:

themachine wrote:

ok, i'v decided on the pistons i'm going to run in my kz1000J, i'm going for the 1075cc 12.5:1 compression pistons think it will be fine running on aviation 100?
i have no clue as to what makes these kz's tick.
so please make some suggestions

1075/10.25, J head, mild cams and I'd stay away from the Av gas. These close to square motors "72/66" can be made to run quite efficintly. This combination can be made to bump the 10s without too much trouble with alittle practice. The "average street squid" on a 600 anything doesn't run that quick. Just don't try to outrun them on the big end.<br><br>Post edited by: modprod, at: 2007/03/02 22:36

unless you get a 1200 kit or a turbo or NOS;)

modprod wrote:

themachine wrote:

ok, i'v decided on the pistons i'm going to run in my kz1000J, i'm going for the 1075cc 12.5:1 compression pistons think it will be fine running on aviation 100?
i have no clue as to what makes these kz's tick.
so please make some suggestions

1075/10.25, J head, mild cams and I'd stay away from the Av gas. These close to square motors "72/66" can be made to run quite efficintly. This combination can be made to bump the 10s without too much trouble with alittle practice. The "average street squid" on a 600 anything doesn't run that quick. Just don't try to outrun them on the big end.<br><br>Post edited by: modprod, at: 2007/03/02 22:36

Well said!

wiredgeorge wrote:

Larry, Are you aware that the same jet needles are used for a GPz750 Dynajet kit as are used for a KZ1000J Dynajet kit as are used for all the 1100cc BS34 kits? With very different needle jets (main jet holder tubes with different diameter openings), the jet needles seldom work well in any BS series application. It is less expensive and more effective to bump the pilot jet up one size (to #40), leave the stock jet needles alone and put in larger main jets (somewhere between #140 and #145 depending on the application). I have STACKS of Dynajet jet needles that HAD to be removed in order to properly tune customer's BS34s. The rest of your advice is spot on. The 10.25:1 kit offered by APE which includes some street cams and a moderate displacement bump is about as radical as a person would want to get if they were interested in all around performance and reliability. If someone wants a purpose built street racer, there are other options but reliability (mostly the ability to shed heat) suffers. I personally believe that the stock 8.25:1 compression pistons offer sufficient performance for a classic bike and if I wanted MORE performance I would start looking at more modern bikes but can understand why some owners might want more modern performance and the look/feel of a classic Kaw. They should just keep in mind that a new 600cc cr will still smoke most any classic Kaw, no matter what mods are done... unless the owner is really into performance mods (nitrous/turbo, etc).

I'll take your word on those needles. We used those kits in 750GPz's and ELR's and they tended to be rich in the mid range but still worked well enough. Dyno Jet used to be real good about replacing needles. They did a set for me and sent the N/C for an ELR that was running rich with ported head and 83GPz11 cams.

Most guys I build motors for opt for smoothbores of one flavor or another right from the start.

The trouble with stock compression piston is you're cam limited unless the pistons valve reliefs are cut. I have a bunch of 1075 motors still running around and they're working on pump gas.

Thos little 600's are running S.O.B.'s but you couldn't give me one...JMO

A properly ported, properly cammed and carbed 1075 KZ is also a running S.O.B. It's comfortable too