4 valve head swap?

OMR has an extra chain and he may let you yank it...

100 hp at the rear wheel? What's the big deal? I have the parts you need to put out 100+ hp at the rear wheel with the right carbs.

Professionally ported 750 cylinder head, Andrews cams, 750 cylinder block and 810 pistons. And a six speed trans and complete gasket set if you're so inclined, and for the right price I'd throw in a Yoshimira exhaust

If you want to fuel inject it, I have 750 Turbo throttle bodies and a MegaSquirt also.

If you change your mind about a turbo, I have a 750 Turbo motor and a Turbo frame with no title

All it takes is $$$$

.

KZ250LTD wrote:

Out of curiosity, why not just buy a complete motor. The chances of you getting a true 100hp will probably be a lot better and possible significantly cheaper...


Engine #1, $450.00

Engine #2, $1000.00

Engine #3, $400.00

Engine #4, $370.00

Thats what I was thinking .

Another thought, but somewhat sacriligious, is to get an early oil-cooled GSXR/Katana motor. I bought one a couple years ago....Thats the next project after I finish the 550


Whichever way that you choose to do it, Good Luck on your project !

Professionally ported 750 cylinder head, Andrews cams, 750 cylinder block and 810 pistons. And a six speed trans and complete gasket set if you're so inclined, and for the right price I'd throw in a Yoshimira exhaust


Im down how much Steell

I have seen KZ's in Puerto Rico with Suzuki motors stuffed in them. Hmmm. They don't look pretty to the eye and I think maybe those motors require a bit more money to build and break a whole lot easier. I dunno. I just bought a zrx1200 with a nice titanium pipe, sargeant saddle and many other goodies for a price so low it would be a crime to mention it but let's just say after the parts that have been added to the bike have been subtracted from the bike with barely 7k on OD the base cost of the bike would only be 900 or less. For an 03?! I love it! This bike cost me less than the cost of the trans and crank cost to get done. I think it a safe bet to assume that although not old school looking or handling it looks old enough with a massive speed freak quality to it. And I can ride it all day long. 900 miles straight and would have been more had it not gotten so cold. My neck was a bit stiff but the seat was incredible. I could actually walk after dismounting this horse. Had I done that on my kz I would have been hurting for 3-4 days after. I remember that monkey butt ride to Grafton to meet up with RiverRoad and those guys.
I love my kz. Would never part with the two I have but man at some point you gotta realize the potential, tap it and call it a day. These bikes are great bikes but when you custom them so much that they don't really look like a kz any more then you have lost the essence of the bike. Just my -.02 but by all means if you are a man with a plan then post the most.

I would think just swapping in the whole motor would be easier.....well, less difficult at least.

ready2ryde1985 wrote:

Professionally ported 750 cylinder head, Andrews cams, 750 cylinder block and 810 pistons. And a six speed trans and complete gasket set if you're so inclined, and for the right price I'd throw in a Yoshimira exhaust


Im down how much Steell

If you have to ask.......

steell I was using dave slone's bike as an example, he has mild porting, cams, 810 annd Fi and the other tricks. last I knew he was getting just about 90 at the rear wheel. I also want the torque curve to stay pretty smooth so I need to stay away from radical cams.

Maybe it won't be easy... but I think I still want to explore it some more.

Evads dyno sheet came up at 82HP... If Dave did get to 90 he would have mentioned it.

I know he's running .360" lift cams with a cleanup port match job with 10.5:1 compression.

Even if he went with some huge cams and a full on ported head that motor would be hard pressed to crack 90 without going to a bigger bore with more compression... you need that big bore to get there without power adders.

This is not player hatin... I just know from experience.

Air cooled naturally aspirated (NON TURBO) 650 based motors - I have never seen a dyno sheet at 90HP for a street motor, except mine... which at that point was a 831cc 13.5:1 big valve, full on drag motor barely able to make it a few blocks without melting my legs off!

Most the 810 based street motors (under 11:1) I have heard of make about 80 HP unless they are running radical cams (+.410") plus the head work to make them breath better (+75CFM)... you also need carbs in the 33mm range (non BS34s !!!)

I am just letting you know because I have built 3-4 big bore non turbo 650 motors - carb or FI... does not matter.

You can't get to the 100HP range working with a small air cooled motor without power adders - a turbo 750 or going to a swapped 900 motor with a 1075 kit, as far as the 2V stuff goes - were talking street going motors here... naturally aspirated you need big CCs unless it is an all out race motor.

You also need to know that HP ratings from manufactures are very subjective and dyno numbers are sometimes also subjective (some more real than others)

Your on the right track with the 4V water cooled idea... that's why they got away from the air cooled stuff in the first place.

Good luck on your conversion - it would be interesting to see what you come up with.

Thank you. I am hoping that kawasaki developed the zx750 from the gpz750 platform and the zx600 from the kz550.

The engineers I know do not like change for change's sake... they want to know why something is better then they will do it (for example look at the trans on the zx600's the first generation zx600 used the exact same trans as the kz550's).

I could be wrong and the parts are hopelessly different, but so far I have one zx750 block, easily re-ebayed if it is a FUBAR idea. If I am right however I will be much closer to meeting my goal.

I must have missed the part where street motor was specified

And Injected is forgetting the third way to increase power, rpm.

These Andrews cams are certainly not meant for a street motor, with the published duration it wouldn't surprise me if the motor didn't start making power till near 10,000 rpm, and the head is fully ported, not a port match and bowl clean up.

I have reliable info that the motor these parts were on was running 9;70 quarter mile with a 250 lb rider, and I have been informed there is another KZ750 motor running high nines on the east coast with a fat rider.

I bought the complete motor after it spun #1 rod bearing on it's third run.

The info did not come from the seller, it was from another source sometime after I bought the motor, and neither the seller nor I knew what was in the motor when I bought it (or it would have cost me a whole bunch more). A case of buying a pig in a poke and getting lucky for once. :laugh:


And again, just to make sure it's clear, at no time did I say it was a street motor, or even streetable (unless maybe you like replacing clutches).

Oh yeah, the head is at a friends as I'm attempting to persuade him to install it on his GPz750/810 with the stock GPz750 cams, just to see what it's like.