810 kit for the KZ 750 motor.

Ituen wrote:

Is the 83-85 GPz750 turbocharged or naturally aspirated?
Boosting the compression to 12:1 or 13:1 may help too on the 810 kit, but I'm thinking a KZ 900 motor or 1000 swap. www.kzzone.com has a ton of parts. Big block motors too.

If you are planning to buy a big block from APE (Kz Zone), then you might want to do it real soon, Jay announced some time ago that APE was no longer making big blocks, and once the stock on hand was gone there wouldn't be any more.

The closest bike dyno to my hometown is 250 miles away in Toronto, Ontario. Too far and not important enough for me to make the trip.

Steell is right. The bike is plenty fast for me. I come in around 5' 10" weigh about 175 pounds and know how to launch, shift and ride to get the most out of my bike. With the mods plus the better low-end gearing this old bike really hauls up to about 75 miles per hour and will surprise some bigger bikes. This is plenty fast for me for street use and since last October if you are caught in Ontario exceeding the posted speed limit by 50 Kmph (about 37 mph) they charge you with street racing, immediately impound your vehicle and licence for one week and hand you a $2000 fine. Pretty draconian measures that are due to the street racers garnering lottsa media coverage with wrecks and fatalities.

Now if I recall from an old post, Steell is just a little taller and heavier than I am (insertion of sarcasm) so he needs the extra ponies to move his Herculean NFL'er frame:-)

Cheers-Colin Firth-Ontario Canada

Now if I recall from an old post, Steell is just a little taller and heavier than I am (insertion of sarcasm) so he needs the extra ponies to move his Herculean NFL'er frame

Only about 5" taller and 60-65 pounds heavier

And probably a lot uglier to boot :laugh:

Let's just say I stand out in a crowd

All joking aside, weight does make a big difference on bikes, I need 20-30 more hp to keep up with the guy that weighs 100 lbs.

Ituen wrote:

Does anyone have any dyno numbers for a KZ 750 with a 810 kit?

Here ya go

hahaha, wicked, i assume thats your turbo bike?

any specs on a 650 w/810 kit? what kind of hp are we looking at? how much improvement are we talking about? anyone take an 810 against a 1000 or 1100? i have a 77 650 motor and just bought an 80 750 jugs. still looking for cams from a gpz750. going to keep the 650 head, mill and port it. what kind of difference are we talking about with the kz750 cams vs. the gpz750 cams. are the kz's are more low end to mid power, where as the gpz cams are more mid to upper range rpm? trying to buy all the parts. jeff at z1 said he thought vm 26's might be a decent carb for the 810 setup. he thought vm29's might be overkill and throttle response might be an issue. any comments on any of this would be great.

cool, i found this too. 810 mod to gpz650

vach wrote:

cool, i found this too. 810 mod to gpz650

You found one of the GPz750 FAQs, there are at least two of them, and you have to read both to get all the info. They were posted in teh "Links" section, don't know if they still are though.

I think one of them leads you to a link to join the GPz750 Mailing List.

well it seems like the mods are basically the same for the kz650 except of opening the case. good info though.

vach wrote:

any specs on a 650 w/810 kit? what kind of hp are we looking at? how much improvement are we talking about? anyone take an 810 against a 1000 or 1100? i have a 77 650 motor and just bought an 80 750 jugs. still looking for cams from a gpz750. going to keep the 650 head, mill and port it. what kind of difference are we talking about with the kz750 cams vs. the gpz750 cams. are the kz's are more low end to mid power, where as the gpz cams are more mid to upper range rpm? trying to buy all the parts. jeff at z1 said he thought vm 26's might be a decent carb for the 810 setup. he thought vm29's might be overkill and throttle response might be an issue. any comments on any of this would be great.

I've been MIA and haven't been around here too much of late so I missed the continuation of this thread. Here is my personal experience with the 810 which has an unusual but solid combination of go-fast goodies inside the motor.

Going up against other bikes is an equation full of many variables: bike's state of tune, driver size, ability and whether or not one of the riders gets a holeshot, either off the lights or on a roll.

I have gone up against a trashed XS100 Yamaha and easily pulled away from the guy at 30 mph. He didn't know how to ride and probably hadn't even changed the plugs since the early nineties. Not a fair comparison but it was fun stomping all over this old heavyweight.

I ran a stock 750 Honda Interceptor at the drags (he redlighted) and I still beat him by half a second in the eighth of a mile run. I remember these bikes when they were new and they would eat a stock 650 without breaking a sweat.

I have pulled away from a piped '83 Kz750 on the highway and I chalk this up to my extra cc.'s and getting up into the powerband quicker than he did. The guy was a bike mechanic so one would assume he had the bike in pretty decent form. He told me that he gave up when he started flattening out and I was still pulling higher revs.

Last summer I lent my bike to a buddy who has a Kz 1000 LTD and he said there was no comparison to his well tuned bike, as the 810 was much quicker off the line than his bike.

I had a little one the roll fun last year with a guy (and his tiny little girlfriend on the back) on an early 90's 750 Kawasaki and they were wondering how in the hell this old bike was staying with them. Granted, my bike probaly weighs 100 pounds more than this 750 but the girlfriend tended to even out the difference. Without the gal pal, he would have left me behind as we were rolling around 40 mph when we started to play on the deserted road.

Can't offer any more info than what I have experienced. If the 810 motor stuffed into a 650 frame isn't enough then you should be looking at cranking up an old Kz 1000 as there is no replacement for displacement:)

Cheers-Colin Firth-Ontario Canada

1977 Kz650 Custom. 650 bottom end, 810 Wiseco, 650 head, milled, ported, Gpz 750 cams, intake valves, springs. Wired George Mikuni 29 smoothbores, Dyna ignition, Dyna coils, MAC pipe, 14 tooth front sprocket. Moondust silver with red, airbrushed lines. Looks stock but it ain't. Bike bought new by my brother now has 15,000 miles on the odometer.

Other Toys:

1982 Ferrari 308 GTSi - 51,000 original miles. Red with tan interior. Appraised $48K
2007 Toyota FJ Cruiser. Yellow 6 speed
1998 Jeep TJ Wrangler Five Speed
2006 Chevy Uplander (kid hauler)
1974 Kawasaki KS 125 Enduro-Restored with only 7600 miles on it.

Life's good if you work smart and are honest!

Well, I guess this is as good a place as any to ask about this...I have a 1978 KZ650 SR that I'd like to put kz750 jugs on, and eventually a wiseco 810 kit. Is it possible to just skip the 750 jugs and bore out the 650 jugs? If so, will I need kz750 cams? Also, either way, am I going to promptly need new carbs, or can I get away with the stock ones, or maybe the stockers from an 81, since they're larger? I really just want to have a kz650 that looks old and decrepit and totally hauls balls, and I can follow the manual and service most things on the bike, but when it comes to performance mods and tweaking, I am at a total loss, so any help you guys could give me, or links to old threads I should be reading or whatever would be awesome. Thanks!