Dear Fellow KZers,
Been a viewer and member for a while. Gotten lots of great info and I've finally decided to post something that could be of some value to all the HP heads out there.
I've owned a low mile (10,000) 79 KZ1000ST (shaft) for about 10 years. Since I've owned this bike I've taken a couple steps to get more power out of it. The graph tells the numbers. (there should be a graph w/dyno results at the top of this post) The mods are as follows:
stock - the stock numbers come from the August 1980 issue of Cycle Guide Magazine
KZ1000ST
74 hp @ 8000
51 lb*ft @ 6500
mod 1 - mild port work on heads (done myself), 4-1 exhaust (don't know the mfg. came with the bike), Dyno Jet Stage 3, K&N filters.
conditions - temp 85 deg, bar press 30.0
82 hp @ 8500
53 lb*ft @ 7500
This shop and Dyno were a little suspect though I think the numbers are fairly accurate. The test was performed about 8 years ago and the bike went into storage shortly after that.
mod 2 - 34mm RS flat slides (120 main jet), heads port matched to carbs (done myself), web 118 cam (properly degreed with slotted sprokets), V&H Street megaphone with baffle removed.
conditions - temp 72 deg, bar press 28.7
90 hp @ 9000
59 lb*ft @ 7500
This shop and dyno were more pro than the first and the test included exhaust gas analization. It was perfomed last weekend. Currently, my RS carbs are running a little lean on the top end. A/F is 14:1 and should be closer to 13:1. Will switch to a 125 main jet. If anyone is interested, I can test after rejetting and post the numbers. Don't expect much...maybe 1 or 2 ponies.
These are random notes/observations/thoughts:
Bike has stock bottom end and pistions w/175psi across all, Accel coils, stock electronic igintion advanced 10 deg (I slotted the advancer plate
mounting holes. this gave me alot more throttle respons in the midrange)
I live in NYC. Both Dyno test were performed in NJ within 30 miles of the city - Effectively sea level. I realize the importance of testing on the same Dyno but...this is what I've got.
Someone once told me that a shaft will waste about 5 HP more than a chain. Fact or fiction? I don't know.
I switched to the RS carbs because I could never get my stock 28mm carbs to run consistently well (after removing the stock airbox and exhaust). They seemed to be very sensitive to alttitued. They would run good in the city (sea level) then I would take the bike upstate to the catskills (2000-3000 ft above SL) and they'ed run much too lean (running with choke would smooth things out). Once I got back to the city they would run fine again. Ditched 'em for the 34mm flat slides. Love em!
Old Kaw Man told me "when running RS carbs and a V&H pipe, you have to pull the baffle out of the megaphone to get the carbs to perform. I played with
tuning for a couple weeks before pulling the baffle...then finally pulled the baffle...He was right. Night and day difference! I would rather it not be so loud but it runs SO much better - even in the midrange.
I also own a bone stock 82 GS1100E in excellent condition. That engine will pull STRONG from 2K to redline. Would love to get that kind of midrange into the KZ. Probably calls for more comperssion i.e. 1075 kit.
I'm certainly not the first to say it but; peak HP and Torque number don't mean much for a street bike. That's why I included the graph.
When this bike is really hot it will use some oil sending a thin steam of blue smoke from the pipe. Compression is good on all cyliniders.? Engine
will also ping between 3 and 4K under load when really hot. I purchased an oil cooler from OKM and will install for next season.
This bike is alot of fun! And the mods have payed off in a big way thanks in-part to the Forum. If the engine had a bit more midrange I'd probably stop
messing with it...probably.
Thanks to everyone for this great resource! Hope my ramblings are of some value. Yours certainly have been...
Dave