1981 Kawasaki GPz550: Restoration

[Nessism]

I'd take all the guts you can and move them over. With only 6300 miles on that engine the internals should be in great condition.

[srsupertrap]

Steve,

Hope you're swapping out the primary chain and starter clutch also, while you have the two motors apart

Good approach Big T, I agree 100% and will add oil pump & secondary shaft & clutch hub too if they are the same. Here are the KZ550 entrails.

Other progress: Just pulled the trigger on a EBay Wiseco K615 & cylinder assembly from an 550LTD. The KZ550 parts bike has the angular fins which are not period correct.

[srsupertrap]

Im surprised that did not bust your crankcases or do some other sort of horrible damage.
Did you dind all the bits in the oilpan? Are these parts still available?

Good question, here is the extent of the damage to the upper case. I will examine it closer but hoping for the best & plan to increase the radius. I want to keep this crankcase since its a survivor (S/N 000030 or maybe its 25). I did fish out most of the shattered cylinder liner parts and will be splitting the crankcase halves this weekend.

PS: Free boat anchor inside, you pay shipping & handling

[Big T]

Steve,

Hope you're swapping out the primary chain and starter clutch also, while you have the two motors apart

[Nessism]

Coming right along Steve. Good work.

Using the head would be very tempting. I'd look at it closely to see if the seats and valves are truly as good as the compression numbers suggest. On my 750 head the seats were uneven for width, presumably from the factory, so that had to be cleaned up even though the engine was low mileage. Don't assume anything...

[rphillips]

I was disappointed with the 1st picture, didn't look like a donor bike. Impressed with next pictures, does look like a donor. Hope things go a lot better this time.

[srsupertrap]

I cut the chain off yesterday with a bolt cutter which caused problems today removing the clutch hub nut today. I pm'd Gearhead13 and he reminded me to use the rear brake to remove the clutch hub nut (Doh!). I used a crow bar wedged between the foot peg bolt to hold the inner clutch hub stationary. The Harbor Freight impact worked as advertised which brings me to the donor. Dr. Steve the donor has been anesthetized . . . I want your crank

[srsupertrap]

Been busy like everyone else but making good progress. The KZ550 donor which I got for $400 looks much better on the outside, Gas tank is totally rusted inside, carbs the same, chain seized solid. PO lived on a road base country road. A field mouse made a nest in the airbox, ate or chewed up the air filter and used the rear frame tubes for a crap pile. The fork are soaked in oil but the fork tubes are good



Another smelly view


Last week before getting serious about dismantling, I checked the compression by running cables from the Tacoma. The girl still has life in her. 150 psi across cylinder 1-4 with oil squirted into cylinder #2. Check out the plugs above.



I had fun dismantling the cylinder head because pretty sure this motor has never been apart. The I & E valve lash were still set to the loose side and every cam bearing bolt snapped loose. Here is what the lash & shim sizes look like. I suspect Kawasaki set the valve lash right in the middle of the range of 2.00 to 3.00mm. I am tempted to use this head considering its condition. Lap the valves, change the valve springs and then replace the valve stem seals it should be tight.

KZ550 Valve Clearance
Date: 4/16/17	Cyl 1	Cyl 2	Cyl 3	Cyl 4
In .004-.008	0.008	0.006	0.008	0.008
Shim	2.60	2.60	2.50	2.50
Ex .006-.01	0.007	0.008	0.007	0.007
Shim	2.45	2.60	2.55	2.60
Compression (Psi)	150	120*	145	150
* 150 with oil

Some must die so that others may live.......

As a 17 year old I used to drool over a neighbours Gpz 550, it's been great reading your thread, even though it has been painful at times. You will get there, keep us all informed when you can.

A strong cup of tea works wonders over here at these moments.

Cheers,
Greg

Oh man Steve, you're killing me! That's the nicest looking parts I've seen in a while! Damn shame to tear that thing apart! A man's gotta do what a man's gotta do though.

+1 To nice for one of my projects

[Nessism]

Oh man Steve, you're killing me! That's the nicest looking parts I've seen in a while! Damn shame to tear that thing apart! A man's gotta do what a man's gotta do though.

[srsupertrap]

Thanks GSers (Nessism, rphillips, SVSooke, Cipher, Ghostgs1) for all the supportive replies. Did want to respond to Cipher's point I was able to fish out the majority of the broken parts from the crankcase. I should have replaced the connecting rod or had it inspected back in August . . . Oh well. I don't the trust the crankshaft now either, everything needs to get replaced. To that end, meet the donor 83 KZ550 Standard with 6300 miles

Same Crank 13031-1014, Same, Rod Assy 13251-1004-KK, Same Valves 12004-1016 (In) & 12005-1013 (Ex), different pistons & cams

[roeme]

Forum cross-pollination! I like it!

Definitively watching this thread.

[srsupertrap]

Oh, so this is where you've been hanging out all these years! I applaud you for sticking with it.

Corey

Hey Corey,
Thanks for watching and checking in, never thought the GPz550 project would take this turn or take so long. For the GS Resource forum community, introductions are in order, Corey is The GPz 550 Forum administrator, resident Subject Matter Expert on all matters of GPz550s with over 16K replies, owns a GPz550 track bike, daily rider as well, overall great guy and works at Motion Pro too. The "Forum Newbie" tag does not apply .

I ran a 1981 Kawasaki GPz550: restoration thread over on The GPz550 forum. Although the number of GPz 550 members are smaller, everyone was just as helpful as the GS Resource Forum. When I had rotary cuff surgery in 2015, then recovered I couldn't find the old thread which explains my absence. Should have because you cannot have enough friends.

BTW, I did rebuild those Mikuni TM27 D1 Flatslides you sold me. The original set on mine sounded really good for about 1 minute.

Steve, Sorry to hear this, that's worse than I was expecting. I think you are correct, all related to the spark plug insulator. Doubt much more damage was caused by the recent attempts at running it, probably all from first start. New liner, rod, bearing insert, but hopefully the crack can be salvaged. Ray