1981 Kawasaki GPz550: Restoration

[srsupertrap]

Thanks JeepRusty

Guys, I need the Moriwaki cam valve lash specification also. If anyone has the Moriwaki cams installation instructions in their magazine collection, aftermarket catalog, performance archive etc please let me know. I have Andrews GS1000 specs (.004 - .006") but that's no help here

I decided to check the valve lash and found some interesting measurements



Looks like the Intake Cams were adjusted to give maximum lift. While the Exhaust Cams were set very loose to perhaps prevent burning a valve? Measurement (In)



Let's review the Moriwaki cam timing specs that JeepRusty found below. Assume I have the street cams would you guys agree with the following cam centerline calculation?

Intake: R1(BTDC) + R2(ABDC) + 180/2 - R1 where R1 = 15 & R2 = 45
15 + 45 + 180/2 - 15 = 105 Centerline

Exhaust: R1(BBDC) + R2(ATDC) + 180/2 - R2 where R1 = 40 & R2 = 13
40 + 13 + 180/2 - 13 = 103.5 Centerline

I got this info from http://medlem.spray.se/biker661/Camtiming/htm (Opps no longer there, I have the hard copy)

To say noting of the uber powerful and sublime gs550e 83 onwards.

[Big T]

One of these days I'm going to have to get one of these. After seeing yours Todd I've had a real itching to have one. We don't see them up for sale very often around these parts, it's probably the same everywhere I guess. Not sure what their production numbers were like back in the day.

Rob,

They sold thousands of them over the years

They were very popular, especially with racers and canyon racers, as the 81 was ground breaking machine. As a result, most were crashed/blown up. I know of 2 others locally

The 82-85 unitrack models are more common as the became less competitive as racers with the rise of the 500 Interceptor and 550 Seca

excllnt we have a winer
that is the bike of my dreams I recall 30 some yrs ago the articles for hopping up these lil bikes.

First gen 550 gpz is the bike of my dreams.
It probably the only mc that I would go without lunch for

[srsupertrap]

Is that and M E oriented logo?
Could be Moriwaki Engineering.

What do you think? I think we have an answer . . .

I also sent a picture to Escondido Cycle Center in CA. which is a Moriwaki importer. Scott said he would forward the picture to Moriwaki Japan to verify.



Another picture



PS: They never replied . . .

One of these days I'm going to have to get one of these. After seeing yours Todd I've had a real itching to have one. We don't see them up for sale very often around these parts, it's probably the same everywhere I guess. Not sure what their production numbers were like back in the day.

[Big T]

Okay, here is a stupid question is Moriwaki Engineering still in business?

Google is your friend

http://www.moriwaki.co.jp/global/

http://www.moriwaki.co.jp/global/partner/02.html

Awesome thread. Always wanted a lil GPZ550. Stock though. All that aftermaket stuff is cool but I have no use for it. Plus it just complicates a restoration/rebuild.

Good luck though. Looks like you have all the help you could need here and on the GPz forum.

Subrscibed. Looking forward to the updates.

[srsupertrap]

Is that and M E oriented logo?
Could be Moriwaki Engineering.

Thanks JEEPRUSTY for posting that information, I will have a closer look when I get home tonight and try to take a better picture too

Okay, here is a stupid question is Moriwaki Engineering still in business?

[Big T]

Hmm, 615 kit, Moriwaki cams, mikuni flatsides, Yosh exhaust

That thing may be faster than your Suzuki

[blowerbike]

yes you would see the weld up from the side of the lobe.
i can't tell from the pics myself.
if you could measure the lift and compare to factory specs that would get you headed in the right direction.

also the casting letter's/numbers might not help.
look on the cam flange where the sprockets bolt on and look on the end on the cams.

also if the cams was of much increase in size you would see clearance work around the bucket's and maybe on the valve cover over the lobes.

lastly...
if the cams was degreed then the bolts can be anywhere in the sprocket slot...that may be where the exh. cam was set when installed.

Is that and M E oriented logo?
Could be Moriwaki Engineering.

[srsupertrap]

GSers & GPzers,
I could still use some help identifying the cams . . . I took some more pictures tonight so perhaps rapidray, Trip or someone could help identify these. Please have a look.

Blowerbike, How does one distinguish regrind cams? I don't see weld lines. Could be stock?

Photo of the slotted cam sprockets, exhaust looks to have moved. We can see R1 directly below the Intake sprocket bolt.



More views of R1 stamping



R2 marked on the Exhaust



View from the other side of the Cam Chain, I also removed the half moon gaskets but no significant marking. E is marked on the exhaust & 8 marked on intake

[blowerbike]

modified stock tensioner...i'd keep it if the cams turn out to be anything much over stock.
put an indicator against the shim bucket and check the lift then compare to stock.
you may have re-grinds in it and they may be hard to identify.