TOPIC:

Quick update...


looks like I have valve issues. Gonna pull the head and have a look-see!

I don't know how I missed the updates on this thread, but it looks like you are well under way to have some track fun. Really excited for you to have fun with that bike. I actually miss racing my GPz550 since retiring it back in 2013(like that was so long ago). I still commute daily on my 1985 GPz550(615), and it's not too far from race trim either.

I read through your whole progress, and I didn't see where those rearsets were identified. They to be Raask. Omars Rearsets sells them, so if you need parts, that place should be able to help. I found Tarozzi Universals worked great, and never scraped the pavement. Like them so much I am still using them on my commuter today.

My experience with carbs is TK27 ('84-85), CV30 (ZR550) and CV32 '85-92 (ZX600C). Simplistically, the TK27 will work for you, as they did for me. If you decide to add a cam, then you might want to move up on the carbs. Initially ran it on a dyno with air/fuel, because I wanted to know, and it all started from there. Any engine mod/change, I dyno'ed it not to squeeze out the power, but to make sure i wasn't running lean. Cams really woke the engine up.

You can even run total loss, by removing the flywheel. I just brought a spare battery, and a trickle charger, and even using the stock starter, never had to battery die out on me. 5 lbs. off your rotational mass does make a difference.

Raptor makes a cool little shift light, than it a 3-wire, and easy to adjust at the light.

Believe me, you won't be looking at your tach.

That GPz550 Engine will make power from 7500-11,000 rpm in stock form. You should get about 55 at the rear wheel.

I added a Trail Tech Oil temp Gauge to the left side of the oil pan, and even when running the larger ZR550 Oil Cooler, I still would get readings of 290*F at the end of a race.

Maybe practice some launches at the local drag strip. Believe me it is a learning experience, and not as easy as it looks.

What size wheels are you running?

OK back to your topic. I have subscribed now. Have fun.

Hey Corey! Thanks for chipping in here! I appreciate it very much!

My little Gpz is just going to be a track bike... no racing! I'm not pushing it to 10/10ths by any stretch. Drag-type launches won't be needed.

That said, I'm liking how you're thinking.

What I have, and what I'm just trying to get sorted and running right, is a complete '85 Gpz engine in my '81 kz550 frame. The donor Gpz was pretty beaten up, so I'm not totally surprised to find some 'issues' to clean up. The valve seats are pitted and worn on at least 3 of the 4 cylinders. They leak pretty badly. Any idea how that would have been caused? In any case, we'll be looking into a repair and then work at getting it properly jetted for the track. We have K&N pods, a Dynojet carb kit and a Kerker KR 'track' pipe on it.

The wheels are 18" Sun aluminum rims. I believe we have a 100 BT-45 on the front and a 120 BT-45 on the rear. Nothing race-worthy, but pretty adequate for track days on the rough pavement here at Toronto Motorsports Park.

Once we get this thing sorted and running for my next foray on the track in September, we might 'look into' some of those mods you're suggesting. No racing though... o'k?

You're welcome, and I'll bring my excitement for you down a notch and remember you are not racing this bike.

Are you planning on using the 85 TK27 Carbs, or are you staying with the 81 TK22 Carbs once the engine swap has been made? If you run the 85 carbs, you will need the 85 throttle assembly and cable. You will also need to use the 85 intake holders.

The clutch is different from the 81 and 85, So you will need to swap the clutch/perch assembly and cable from those bikes too. Here is how I route my stock clutch cable with pod filters.


Not sure about the valve seat pitting, but looks like a head go through is on your radar.

The bottom ends of these engines are very stout, and as long as you keep clean and fresh oil flowing, it will last a long time.

Look forward to reading your progress.

Yep Corey, we have the whole '85 Gpz engine, carbs... the whole shootin' match! We were changing the needles and jets to suit the K&N pods, when we discovered the valve 'issues'. Yes, we'll be looking to get a little work done on the valve seats, etc.!

Well, sending the head out for some 'massaging' tomorrow. Hope to have it back in 10 days or so.

Well, 10 days and no word yet...

September's coming fast!!

2 weeks and still waiting for word on where it's at.

Maybe this week.

Too bad on the wait Drew.
Are you going to Mosport next weekend?
I hope to be there Friday or Saturday.

rstnick wrote: Too bad on the wait Drew.
Are you going to Mosport next weekend?
I hope to be there Friday or Saturday.

Hey Rob... but of course I'll be there!

Well, the rebuilt head finally found it's way home.

So, on with the rebuild. I'll get some pics up asap.

Well, we got the head back on but there's some valve adjustment necessary.

I've lost my work space for a while though, so I'm getting a buddy to do the final set up. Kinda sux, but I wanna put this to bed before the winter really sets in.