1982 GPz750 Phase II Making It more Unique.

swest wrote: Well if you're going to redo it, might as well make it better than it was. :woohoo:
Steve

No doubt. The question is, how much better? Money is also a factor the 810 kit is a few hundred bucks then boring and rejetting on top of that....

I'm sorry to hear about your accident! I'm glad you didn't end up with an ambulance ride.
It is a sobering reminder to me of the risks I take when just tooling around on my bike in town.

I'm glad you aren planning to build a replacement engine rather than throw in the towel.

As some have pointed out, the zr-7 head is a way to easily replace the head. They are plentiful on ebay and will bolt right on. But I believe they are cosmetically different enough to require their own matching cam cover.
The 83-86 gpz/zx750 heads will work, but note that the exhaust valves are recessed into the combustion chamber by .50mm which makes shimming exhaust valves to your current '82 cams a royal pain. But the zx750's had better hotter cams, so if you go that route, get the matching cams and you will be better off in many ways.
I ironically searched for an '82 gpz head as those where factory ported and polished by Kawasaki. Instead, my '81 head turned out to be in better shape than I thought and I just did my own port and polish and had a valve job done. ( shimming the zx750 cams into my '81 head is a work in progress.) It also remains to be seen if my 810 pistons interfere in any way with my NON bathtub heads.

As for the 6-speed swap, it is totally up to what kind of setup you want to end up with and how much you want to change or spend.
My entire goal was to retain the exact factory gear speeds and rpm's, but add on a "highway" gear. This required not only the 6-speed, but different front and rear sprocket ratios combined with a 530 chain pitch and my custom rear wheel size. I was already needing to replace all of those things anyway, so it was a non issue for me. You may have no intention of spending the extra money on things you don't need to replace.

GPzMOD750 wrote: FUCK!!!

Well apparently this isn't my day. I just dumped it taking a short cut to fill up on the way home. Looks like I'm done riding this summer. At least this bike.

Damage doesn't look too bad but my DynaS is toast. I have spares for almost everything already.....

I was turning left here. That's enough dirt to break my tire lose apparently.


I'm ok, shoulder is little sore. I was wearing gear so I won't have a ton of road rash.


Waiting for a tow......

I'll post pics when I get home.

CRAP!! Man I had this happen to me last fall.
Don't feel so bad though because I went down in some sandy junk in a slow speed 25mph left curve 48 miles from home.
I slid over to the shoulder under complete control (old motocross rider) but hit the super soft shoulder dirt and the bike just stopped dead at the rear and high sided me. Damage?
Bent my brake lever a bit, the handle bar, scratched up my points cover, bent the RT turn signal stem, knocked the headlight brackets all to Hell and scratched the crap out of my tach cover.
Repair costs were minimal but the bad news was my right foot went under the engine, my Achilles tendon got caught by the FRONT of the foot peg rolled my foot up...
That broke two toes, dislocated three, stretched the tendons in my toes to the breaking point, bruised three ribs and my MF'r medical bills with rehab were almost $12,000,00!! Jesus H Christ. $12,000.00.... probably three times the value of my F'n bike.

Drove the thing home nearly 50miles in some serious pain.... almost four weeks on crutches and no way to ride.... until this spring.
So, put it all into perspective my friend!!

Daftrusty wrote: I'm sorry to hear about your accident! I'm glad you didn't end up with an ambulance ride.
It is a sobering reminder to me of the risks I take when just tooling around on my bike in town.

I'm glad you aren planning to build a replacement engine rather than throw in the towel.

As some have pointed out, the zr-7 head is a way to easily replace the head. They are plentiful on ebay and will bolt right on. But I believe they are cosmetically different enough to require their own matching cam cover.
The 83-86 gpz/zx750 heads will work, but note that the exhaust valves are recessed into the combustion chamber by .50mm which makes shimming exhaust valves to your current '82 cams a royal pain. But the zx750's had better hotter cams, so if you go that route, get the matching cams and you will be better off in many ways.
I ironically searched for an '82 gpz head as those where factory ported and polished by Kawasaki. Instead, my '81 head turned out to be in better shape than I thought and I just did my own port and polish and had a valve job done. ( shimming the zx750 cams into my '81 head is a work in progress.) It also remains to be seen if my 810 pistons interfere in any way with my NON bathtub heads.

As for the 6-speed swap, it is totally up to what kind of setup you want to end up with and how much you want to change or spend.
My entire goal was to retain the exact factory gear speeds and rpm's, but add on a "highway" gear. This required not only the 6-speed, but different front and rear sprocket ratios combined with a 530 chain pitch and my custom rear wheel size. I was already needing to replace all of those things anyway, so it was a non issue for me. You may have no intention of spending the extra money on things you don't need to replace.

ZX750 head it is then. Any changes in the rods or pistons, i.e. cam journal, wrist pin sizes, I need to worry about?

I think the 810 will have to be decided on later determined by my bank account.
(Selling some parts probably wouldn't hurt the situation.) And I can always do it later.

I'm already running a 530 chain rough equivalent to one tooth up on a 630 rear. I'll bet if I go one more tooth up I'll be more than happy. Sprockets are cheap...

It depends if you re-use your '82 crank or rods as the '82 was also the one year only for piston oil squirters. Kawasaki stopped using them for fear that they robbed to much oil pressure. (But, if you are going to use a Zr-7 oil pump, that will not be an issue. ) EDIT: So they use different connecting rod bearings than the other gpz's and they can be expensive.
The zx750 cams drop into any kz/gpz head. Only the exhaust cam base circle is smaller which is what complicates valve shimming on non-zx750 heads.
The wrist pins are all identical through out the years.
Not that you mentioned it, but just in case you considered it.....The Zr-7 crankshaft has a splined ignition rotor, so if you want to use a Zr-7 crank you are kinda forced to use a Zr-7 ignition setup and module. Otherwise it would fit in a gpz engine case.

I was kinda "forced" into the 810 pistons as my bores were beyond tolerances and I wanted higher compression pistons than the stock 9:1 anyways.
So initially it made sense to just get 69mm Pistons and bore out my cylinders rather than find good used 9.5:1 pistons and a usable cylinder block.
But just the cost of boring out the cylinders by a reputable company has put me deep in debt not to mention the cost of the 810 pistons. If you can reuse your stock pistons and cylinders...do it.

Don't get to bummed out over the crash, the bike can always be fixed but not you so as long as your not too hurt everything will be fine.
In 2011 I crashed my 78 KZ650 which I have owned since new and on it's first ride after a frame up redo. Went down at 80 mph during rush hour on one of the busiest freeways in California the I-14 to I-5 interchange. Slid across 4 lanes of traffic my bike flipped end over end and I though for sure I was going to be run over by a car. I stopped on the side of the road with only a broken wrist. My riding gear saved my life, Yeah. The bike was totaled, I dragged it home a week later and it sat in the corner of my garage for a year. I would go out and stare at it and cry every once in awhile. In 2012 I manned up and redid it, with help from several member here it's back on the road better than it was before the crash.

2010 right after rebuilding it

May 2011 crash, 500 miles after the above picture was taken

Broken wrist

Now after new frame and body work and LOTS of blood sweat and tears.

Bummer. Wish I had pics of Bossie after the wreck. What caused it?
Steve

F*&King asshole talking on a cell phone during rush hour traffic. Like an idiot I let myself get boxed in and I had nowhere to go when the asshole wandered into my lane and hit me. First crash in over 30 years of riding LA traffic. CHP found the guy at fault however since he never stopped and no one got a license plate number I was out of luck.

Daftrusty wrote: It depends if you re-use your '82 crank or rods as the '82 was also the one year only for piston oil squirters. Kawasaki stopped using them for fear that they robbed to much oil pressure. (But, if you are going to use a Zr-7 oil pump, that will not be an issue. ) EDIT: So they use different connecting rod bearings than the other gpz's and they can be expensive.
The zx750 cams drop into any kz/gpz head. Only the exhaust cam base circle is smaller which is what complicates valve shimming on non-zx750 heads.
The wrist pins are all identical through out the years.
Not that you mentioned it, but just in case you considered it.....The Zr-7 crankshaft has a splined ignition rotor, so if you want to use a Zr-7 crank you are kinda forced to use a Zr-7 ignition setup and module. Otherwise it would fit in a gpz engine case.

I was kinda "forced" into the 810 pistons as my bores were beyond tolerances and I wanted higher compression pistons than the stock 9:1 anyways.
So initially it made sense to just get 69mm Pistons and bore out my cylinders rather than find good used 9.5:1 pistons and a usable cylinder block.
But just the cost of boring out the cylinders by a reputable company has put me deep in debt not to mention the cost of the 810 pistons. If you can reuse your stock pistons and cylinders...do it.

Thanks,

I've been looking on ebay and can only find 1 non turbo 83-86 ZX750 head and it doesn't look so hot. No cams or caps and no shims and one bucket is missing. I guess I'll keep an eye out...

baldy110 wrote: F*&King asshole talking on a cell phone during rush hour traffic. Like an idiot I let myself get boxed in and I had nowhere to go when the asshole wandered into my lane and hit me. First crash in over 30 years of riding LA traffic. CHP found the guy at fault however since he never stopped and no one got a license plate number I was out of luck.

Yeah, another reason for the bike cam. Left LA in 76 and never looked back. It can happen anywhere. :dry:
Steve

swest wrote:

baldy110 wrote: F*&King asshole talking on a cell phone during rush hour traffic. Like an idiot I let myself get boxed in and I had nowhere to go when the asshole wandered into my lane and hit me. First crash in over 30 years of riding LA traffic. CHP found the guy at fault however since he never stopped and no one got a license plate number I was out of luck.

Yeah, another reason for the bike cam. Left LA in 76 and never looked back. It can happen anywhere. :dry:
Steve

I'd like to get one of those Go-Pro things...
But really, keep in mind that motorcycle riding carries a much higher risk then say, driving your SUV to the grocery store or across town!
And if you have been riding a motorcycle for as long as I have or many of us have.... there is a pretty good chance you've been knocked off or spit off one!
LOL

I don't know how many times I've been down in the last 40 years. I do know the first year was the worst. 350 Honda so it wasn't too bad. Mostly stupid things. The drivers around me has always been my biggest concern. The cam is under $50 delivered and I hope to have it on the next time I get cut off or worse.
Steve