1981 Kawasaki GPz550: Restoration

[srsupertrap]

I could buy a Proform 66785 Manual Ring Grinder on Amazon/Ebay but delivery pushes assembly out. Checked out You Tube this morning and found this video which makes use our the handy dremel tool.

https://www.youtube.com/watch?v=YSTPdZA3KV8

I purchased a Dremel grinding kit about a decade ago, I have used lots of Dremel 420 cutting wheels but never anything from the kit. I decided to test the grinding ability before moving onto piston rings. Pulled out the damaged connecting rod, s/b steel.

Looks like I have the right equipment just have to fixture everything. Wiseco rings are only .8mm thick

 

[srsupertrap]

Here is my version of the You Tube piston ring grinder; I switched to a finer grinding wheel for more control. Price was right!

All the top rings now have .013" piston ring gap, second ring measure .017"

Bought a EBay piston ring expander but its too big for the Wiseco .8mm rings

Installed the new Wiseco 615 pistons too

PS: Still looking/need 1981 GPZ550 camshafts (Tach Drive). These cams are identified by two circular grooves on both In. & Ex Cams adjacent to the Cam Sprocket.

 

[srsupertrap]

Weekend update. Wonder if I should use any RTV on the base gasket before I move onto the cylinder head

 

[dweller]

This is a great build. Keep it up!

 

[roeme]

Weekend update. Wonder if I should use any RTV on the base gasket before I move onto the cylinder head

Friend of mine recently replaced the base and head gasket on his Z500 and did use RTV.

 

[exdirtbiker]

I would do what ever the factory did... esp. if you're using factory gaskets.

 

[srsupertrap]

Yep using factory gaskets, so I will skip the black RTV around the cam chain tunnel.

Regarding cams, I sold those Moriwaki cams and just received a set of 81 GPz550 cams on Monday which is the only GPz model which a tachometer drive. The later H1, H2 & ZX550's all used electronic tachs. I am using a ZX550 cam (Same .325 lift & different duration) for the intake which I bought from Corey and 81 exhaust cam which Corey also located for me on EBay. Last night I benched shimmed the exhaust cam. What caught my attention while bench shimming both cams was the fact that the shim size before and after the "valve job" did not really change. In some cases not at all . . . Hmmm

No longer using the adapter plates for the Mikuni smoothbores but decided to use the Felpro gaskets with a film of black RTV to fill in the uneven surface on the carb boots I purchased back in 2014. Installed 8 new allen head screws

Installed some of those compressible fibre exhaust gaskets. I purchased them from an EBay seller in the UK and unfortunately found the OD was too large. Although the seller sent me replacement gaskets, apparently my experience was not an isolated case. I like the design but the quality sucks . . .

[/IMG]

 

[srsupertrap]

Some more progress, assembly should move pretty quickly. Decided to use Valvoline 4T 10W-40 for initial break in

The cylinder fins are polished like the original 1981 GPz cylinder head

Torqued to 17 Ft-Lbs

Camshafts went in no problem, liberally lubed all contact surfaces with CRC assembly lube, check valve lash later today

Need a T electrical connector like the one below, If you have an extra please PM or let me know.

 

[Corey]

Hi Steve. Great progress.

Could you elaborate more on that connector? I will see if it is used on my A Model. Here to help.

 

[srsupertrap]

Thanks Corey, I might have found one of those T-shaped connectors. More progress over the warm Thanksgiving holiday

I used Threebond 1184 on the half moon gaskets

That damn exhaust header may tuck in tight but the exhaust port spacing between 1 & 2 and 3 & 4 cylinder fits like crap. If I ever find a Supertrapp header I will sell it in a second and be happy to have a centerstand back.

Be installing the cables & K&N's tonight

 

[nvr2old]

Gettin' close.... Looking forward to the finished product.

 

[srsupertrap]

Same here Larry, with some mild weather I finished up on Sunday. Those Mikuni smoothbores were only made for the GPz550 not exactly a smart marketing move by Mikuni. I have also heard the stock GPz throttle cables don't work on these carbs but I have never had an issue.

The Kz550 parts bike donated the owner manual and plastic case which fits neatly in the cowl

Old New Mexico plate circa 1994 when the PO likely parked it. My new plate. Still have to modify
chain guard so it doesn't contact the rear wheel

 

[alke46]

Man, this thing really turned out nice. Worth a lot of coin in this condition, I would think.

You must be proud of all your efforts and your talent level and attention to detail is very admirable.

 

[Zaddict]

Inspirational job, really beautiful work. I learned a bunch reading this thread. That thing is going to be so much fun to ride!

 

[Nessism]

Won't be long now Steve! Can't wait for the video of the first start! You are taking one aren't you? Ha ha, easy for me to say. I've never done it. The first ride may require a snowmobile suit too eh?

Looking good and fingers crossed for a successful transition from project to runner!

 

[srsupertrap]

Man, this thing really turned out nice. Worth a lot of coin in this condition, I would think.

You must be proud of all your efforts and your talent level and attention to detail is very admirable.

Thanks Larry, I am not sure what it's worth but I do like the modifications the PO did. Looking for a warmer day and some spare time before giving it whirl.

Won't be long now Steve! Can't wait for the video of the first start! You are taking one aren't you? Ha ha, easy for me to say. I've never done it. The first ride may require a snowmobile suit too eh?

Looking good and fingers crossed for a successful transition from project to runner!

I hope so Ed. Although I am confident the second build should start right up there is always unknowns like the crank bearing tolerances etc . . . I will try contacting Gsghost1 to help with the video . . . again

 

[GregT]

I've just recently had a race 550 through the shop. He'd had an inlet cam sprocket bolt come out and had broken the piece off the cam...
So went through his existing head, finding that it needed several valves which came from his spare head stocks.
Reshimmed it and handed it back with an inlet fitted from a spare head. Ok so far...
I suggested to him that it was worth him bringing the bike to me to dial the cams in once he'd refitted the head as I'd noticed a mixture of cam sprockets...
Sure enough, the actual cam figures didn't match any model in the manual.
So dialled them in to 104 inlet, 106 exhaust.
He wasn't too happy when he took it out at the major meeting he'd been getting it sorted for - it was hitting top gear about 100 yards earlier than before and could easily have used a gearing change...

Anyway the moral is that mixing cams and sprockets may not give you the timing in the book....

 

[Corey]

So, any new progress on this? Looks like you are getting ever so closer.

 

[exdirtbiker]

Did you find more of these? Looks very much like the battery plug on my Grandskids' 6V battery powered ride-on toys.

 

[srsupertrap]

So, any new progress on this? Looks like you are getting ever so closer.

Well like many parts of the country I need some warmer weather on a weekend. Last week was zero overnight here in Colorado and the weekend was no better. One last issue, the plastic chain guard lost its original shape. Unlike a GS chain guard which is rigid plastic the GPz/Kz chain guard is pliable and the width of this one expanded to the point where it's presently rubbing the rear wheel hub. I have had several chain guards in my possession now and the all have the same problem. Maybe I should use an LTD chain guard which is chrome metal but that would look weird.

Did you find more of these? Looks very much like the battery plug on my Grandskids' 6V battery powered ride-on toys.

Yes I did. Jeff Tuttobene sold me one from his electrical connector collection. I will have to follow up with him on the kit information but I believe he purchased one of those vintage Japanese electrical connector kits. He raced those GPz's in Box Stock back in the day but recently sold his GPz550 eye candy pictured below.