700cc 650 - worthwhile?

GPz750 oil cooler setup would be easier, and it's a full flow cooler, all the oil goes through it before it goes to the motor.

The GPz750 oil pan has both the inlet and outlet on it, the main oil passage from the pump goes through the bottom of the case, then drops down into a passage in the pan, then back up into the motor again. The GPz750 pan splits the passage in the pan out to the cooler then back in again.

I'm not to fond of bypass coolers on the plain bearing KZ's (550/650/750) because I just don't know if the pump has the excess capacity to make up the volume and pressure lost to a bypass cooler under all operating conditions.

All the aftermarket oil coolers that I have seen for the KZ's are bypass type.

If you have access to a TIG welder, you might be able to split the passage in the 650 pan and weld on an outlet and inlet.
Never tried it though.

What kind of swing do you have on your lathe? Enough to bolt the block to a face plate and bore all four cylinders?
I think it would probably take at least a 20" swing.

Yeah, I gotcha, I was wondering about capacity and the like myself...I'm an engineer.

Yeah, dont have a lathe big enough for that, the biggest I have access to is a 16" King, and thats garbage compared to the Colchester I normally use.

SO I'm on the lookout for a GPz750 Oil pan and cooler...what years did you way bolt right on? oh, i see it, 83-85...

77_650B1 wrote:

your rings sealed perfectly in a newly honed cylinder after 4 revs? wow, yer my hero, i thought that took miles and miles of breaking in.

I pulled the rope a few times and no vac at the intake port, a few more pulls and the rings seated fully, that machine never ran well according to the owner but it had alot of snap after the rebore. Originally there was 12thou between the piston and cyl. He informed me that his son raced motocross and the diff. between a wiseco pis and a suzuki is half life. And showed me how the piston shrinks from skirt to skirt. This one probly 4 or 5 thou. This guy knew what he was doing and told me he did work on the side too, 20 a hole. I asked another shop that did my 900 to leave 1.5thou clear. and he said i wouldn't do it not on an air cooled motor. I wish I had told him to do it anyway. The bores WERE off center and i did complain but they got defensive and i let off the subject. I sent my 900 head to an auto machine shop in town and they cut my valve seats for 14.00 total. The kid said he blended the bowls for me and asked what the head was from. Nice price, nice work and extra consideration. I had the same shop bore a 350 and mike everything for 100.00. He checked the oil passages for me and cleaned ev. up. As long as they know what cautions are involved with the motorcyle head they can do some nice work.

Yes, yes, thats fine. No hard feelings man, we're just staunch believers in tolerance thats all, I'm a little bit of a machinist, and steell seems like a fully fledged one.

So steell, last question. Will a GPz750 Turbos's oil pan and cooler from those years work as well. I'd imagine they had the same engine, just different CR's, just want to make sure though.

I know the 83-85 GPz750 pan and oil cooler will bolt on the 650/750 motors and work, there are several people here that have done it.

I don't know if the earlier GPz750's even used an oil cooler, I have never had one

The 750 Turbo is a little different than the regular GPz750, it has an extra oil pump to scavenge oil from the turbo, so I don't know if the pan will work.

If you have access to 750 Turbo parts, I need a clutch basket off one

Naw, i just found a cooler on ebay, thats all. The guy has got a transmission from a turbo 750 though, heres the link to his store.

stores.ebay.com/Jacks-Used-Cycle-Parts

Hey,

I've been looking on kawasaki's parts diagrams, and theres isn't a GPz750 listed for those years, just the ninja 750. Is this what I'm looking for?

Thanks

Edit: Nvm, figured it out (says GPz on the fiche, but not when you're searching)

Kawasaki.com parts diagrams are kind of weird, you have to use 740cc as the displacement for 1980 KZ750E, and 1020 as displacement for pre 81 KZ1000's.

83 GPz750 AKA Ninja 750R, ZX750A1-A3.

I sold 3-4 oil pans to members, saved the last one for myself

I screwed up and sold all my GPz750 cams to members, then had to turn around and buy a set on eBay that cost more than what I sold mine for :blush:

Aww, that really blows. Do you think I should get GPz cams and intake valves while I'm at it too? Would it give me a lot of increase?

What kind of riding do you plan to do with the bike? Is it going to be a daily driver, a commuter, a streetfighter that only comes out on nice evenings, or?

Take a look at what reborn650 has done to his bike, he rides it fairly often and seems to be real happy with it.

I have a 750 twin for a daily driver, and I love it for that purpose, my KZ750E four cylinder project bike is a different animal, rearsets, no passenger pegs, Suzuki front suspension and wheels with a modified GPz750 swingarm, fuel injected, GPz750 cams in one motor with MegaCycle cams in another motor (I have 3 motors), etc. It's just a go fast at all costs bike, I'd hate it for a daily driver.

Build it to handle the way you plan to use it, or have different bikes for different purposes

I PM'd reborn650 and asked him to pop in here and tell you about his 810 650, he did an excellent job with it.

My problem is that i want my daily driver to be absolutely nuts, but also very reliable, aka it starts without trouble and i dont have to screw with it all the time. i'm a bit of a nutjob, and cant abide slow vehicles. i think what i have planned, the valve job, 810cc, and a carb rebuild and rejet will give me the oomph i'm looking for. the suspension upgrades will do the rest. i think i'm happy without going nuts with different cams valves etc.

i want my daily driver to be absolutely nuts, but also very reliable, aka it starts without trouble and i dont have to screw with it all the time.

What you want is a GPz750 Turbo, starts with a push of the starter button and just sits there idling smoothly.

Then, you take off, yank the throttle wide open, the tach hits five grand, and your arms get yanked out of their sockets :laugh: