1981 Kawasaki GPz550: Restoration

[Cipher]

restock them in a special place till you come back for more I'm thinking.

[srsupertrap]

Did some assembling this last weekend



Although tucked in tight the Yoshimura exhaust doesn't fit all that well. Lot of effort to get the exhaust collars spaced properly

[MaurieG]

What a thread! What a build! Read the whole thing in a sitting! Steve, you've had some luck, mostly bad! But, when it fires up, and you've got a few miles under your belt on it, all that pain will be worth it! Good luck with the rest of the build!

[Killer Canary]

I can't wait for a ride report.
Back in the day I heard that these could kill a 750.

[srsupertrap]

Thank you MauriceG. I actually made more progress. Carbs are next and might get installed if the Super Bowl becomes super boring.



Don't like loosing the centerstand & oil filter access but on the plus side the Yosh exhaust is tucked in real tight
PS: IF anyone happens to ever run across a 1980-83 KZ550 Supertrapp 4 into 1 header please let me know since I have the NOS muffler which keeps centerstand etc.

[thebrandonbeezy]

Thats a beautiful bike man, glad to see its going back together

[srsupertrap]

Decided to replace the chessy plastic fuel filter



Emgo 5/16, 3" overall length



Most would say leave it out but I found some fine particulate in the carb bowls

[Nessism]

I like that filter. Good pickup.

[srsupertrap]

Getting down to finishing touches . . . found a tool tray on Ebay. The tray is not secured and just sits between the battery box and frame rail. No wonder they're scarce




picked up a tool kit when I first started this project and it barely fits

[Big T]

Steve,

Did you ever get it fired up?

[srsupertrap]

I need some help getting it out of the living room now that's assembled & heavier. I wheeled it up the stairs by myself but that was disassembled. Plan to have Ray shoot the video . . . again. How does that sound Ray?

[Ghostgs1]

Sure Steve, this weekend?

[srsupertrap]

With the help of Scott, my neighbor the GPz is back in the garage


Ray came over Sunday, we started it and immediately noise came from the #1 cylinder. Ray characterized as misfiring or incorrectly timed I thought it was similar to noise when it ate the spark plug electrode in August . . . it ran a whole 5 seconds maximum before I shut her down.

We didn't see much value in starting it up again. Scratching our heads Ray suggested perhaps a valve was stuck but we ruled that out. Ray suggested perhaps the wires to the coils were reversed and it was firing 180 degrees out. I jumped on that idea because I was not looking to disassemble this thing yet again and was hopeful for an easy fix.

I ruled that out pretty quick by reviewing the wiring diagram & photo of Coil 1-4 below when it was disassembled back in Dec 2013. The Yellow/Red is the switched power going to both coils, the black wire going to the bottom of the coil indicates it's Coil 1-4. The green wire goes to Coil 2-3 and plug wires go to correct cylinders. . . I verified that was correct.



The culprit could be the Dyna S wiring i.e. switched. I took several picture in 2014 but couldn't tell which wire of the Dyna S was installed in the 4 position connector (Kawasaki Wiring Description). Below is the Dyna S which is a bit confusing because Dynatek shows a Black wire going to Coil 1-4. In reality 1-4 is the pick up on the left side which I redlined, it's a White wire which has a heat shrinked black sleeve on it. Conversely 2-3 is the right side pick up which I also redlined. The 2-3 is a black wire which has a heat shrinked green sleeve on it.

Glad you're following because back in August I installed a new connector to eliminate the PO jury rig. The index card wiring below reflects the wiring which goes to the 4 position connector which I believe is on Page 30 +/- page. The rectangular symbols represent the heat shrink. The wires from the bottom represent the Dyna S wiring. That being said it looks correct to me.



I will have to perform a static timing check per Dynatek's recommendation to determine if I have correct spark to the right cylinder. Just to throw another variable into the mix, I performed the static timing test back in August and with the #4 spark plug removed, grounded to the cylinder head nut I saw it spark.

We also turned over the engine with spark plugs installed and the plug wires removed from the spark plugs. That sounded completely normal. . So the noise is attributable to firing, compression, mechanical damage or other. Feel free to ask questions or comment on what could cause the noise Ray (Ghostgs1) & I heard.

[Ghostgs1]

No good answer that I can think of. Do you think it is possible that the crank through moved when the piston hit the ceramic? Long shot. You could possibly check for this with a dial indicator in the spark plug holes, comparing distance to the pistons at indicated top dead center. If they are not all the same, that would be a good indication that all isn't well.

[srsupertrap]

Checked & rechecked items on Saturday including Static timing, compression check, piston location, verified Dyna S wiring was correct, coil wiring was correct nothing reversed etc. The compression check albeit low was consistent across cylinder 1-4. Then I recalled when reinstalling, the Yosh pipe in February one fibe exhaust gasket OD was too large. I made it fit by unwrapping several windings from the OD, trimmed the excess, reinstalled thinking I was good which led me to believe Saturday night maybe all I had was an exhaust leak.

Sunday I tightened up the exhaust system bolts, started it and was greeted with a loud knocking noise from the intake cam which is a different than the exhaust leak. Sounded like excess valve lash with a running clearance of .25" (exaggerating). Recall I went to all the trouble of grinding valve stems (.50mm to .70mm) max to correct the valve lash and bench shimmed the head etc. What I can share is the machinist from Iowa milled off material from the top of the several valve spring retainers but didn't increase the counter bore depth. With the valve shims installed in the retainer several shims actually rocked back and forth (red X) and one shim once installed could not be removed. To alleviate that situation I replaced those valve spring retainers with EBay KZ550 un-machined valve spring retainers, the rocking valve shims went away and the shims could be easily installed & replaced. Apparently some valve stems were no longer contacting the valve shim. That's the only thing I can deduce. I think I heard a valve spring keeper came loose but won't know till I open it up . . . again


4/4: I pulled the valve cover tonight. I turned the engine over by hand, no mechanical interference felt & crank resistance seems normal. Cam sprocket bolts installed and have not moved. Checked valve lash on 3 & 4 Intake which measured .009" & .008" respectively which is were I set them. I will check rest Wed.
Sounds like a stupid idea but can I learn anything from running it with the valve cover removed?