TOPIC:

CoreyClough wrote: Thanks for your feedback and sharing your experience.
On the clutch issue, I'd make sure there is play in the clutch cable, and a little free-play at the lever. This would be a tight clutch cable, and not releasing completely.
Higher rpm clutch slippage usually leads to needing a clutch replacement. Cut to the chase, and replace the springs, steel plates and fiber plates. Once you remove the old clutch you might see what it is. I have had great experience with Barnett Clutches, not so good with EBC.

thanks.
no problem of freeplay in this case. it has started to slip after an oil change and carb cleaning, and I suspect the old oil was masking the problem with a lack of proper lubrification, I've been abusing of rodeo starts at the red light for too long too...
EBC kits are easy to get from ebay, but I don't know Barnett's
EBC not good for racing, but still ok for a street rod?
any source for barnett kits that ship outside usa? differences in term of cost? barnett's clutches suitable for regular driving?
excuses for all those questions, but there's not so many opportunities to learn from this bike where I am.

Also, I've had clutch slippage after oil changes on several occasions. It turned out to be the oil level was too high. I filled it to the top of the sight glass, but then would get high-RPM clutch slip. If I leave an air bubble at the top of the sight glass, it seems to be fine.

loudhvx wrote: Also, I've had clutch slippage after oil changes on several occasions. It turned out to be the oil level was too high. I filled it to the top of the sight glass, but then would get high-RPM clutch slip. If I leave an air bubble at the top of the sight glass, it seems to be fine.

you are probably right. I might have filled at the upper mark or just below, but I didn't overfilled. this, and considering modern synth oïl efficiency could cause slipping.
but I think that it started like this, and that now clutch has weaken. I may have to change a cluch kit now

Just a quick update on this. I went ahead and slotted a cam gear in preparation to advance the intake a few degrees, but after rejetting I don't think I'll bother - the bike is running ***AMAZING***. Great throttle response and I got back tons of low-end. Butt dyno says the bike is making more power across the rpm range pulling strong all the way deep into redline. All I did was switch the pilots from #35 to #38 (with screws set 3 1/2 turns out using the lean drop method), and switched the main jets from 112/115 to 110/112. The bike hauls ass! Who'd of thunk a little jetting adjustment could have such an strong impact? Mileage is better as well- hit 40mpg this latest test ride, and that was driving like a complete lunatic doing at least 10-15 off-the-line blasts. In any case, moral of this story is if you're thinking of swapping zx cams into to your kz or zr 550, do it! (and rejet)

Cheers,
Mark

No eBay APP ID and/or Cert ID defined in Kunena configurationGlad you got this sorted out. Did Factory Pro assist you with this on another dyno visit? Please list you complete jetting using the air box and CV30 Carbs. Other might want to follow this same path.

Using a tool like this wide band air/fuel system, will aid in fine tuning those carbs for the street. I bought one, and just need to add the "bung" to my midpipe. You can find the complete kit on Ebay.

www.innovatemotorsports.com/products/db.php

CoreyClough wrote: Did Factory Pro assist you with this on another dyno visit? Please list your complete jetting using the air box and CV30 Carbs. Others might want to follow this same path.

I just went with Raul's rejetting suggestion from the last run. Actually he said "go down 2 sizes on the main and up 1 size on the pilot." Looks like the jet sizes jump in increments of 2-3, so I'm not exactly sure what he meant. In any case this is my current setup:

CV30 carbs
Main Jet = 110 for carbs #1,4, 112 for carbs #2,3 (down from 112 for carbs #1,4, 115 for carbs #2,3)
Pilot Jet = 38 (up from 35)
Needle = 0968h-66u, /2 clip position with 2 washers above clip (unchanged from before cam swap)
Float height = 17mm (unchanged from before cam swap)
Mixture Screw = 3.5 turns out (up from 3 turns out, and changed pilot jet)
stock airbox with K&N Filter (unchanged from before cam swap)
Kerker stainless steel race exhaust with 1.5" competition baffle (unchanged from before cam swap)

Results are phenomenal. Couldn't be happier with my little beast. She even sounds meaner. I'm thinking about doing another dyno run as my butt dyno tells me power is way up on low/mid and I'm curious what the actual numbers are. We'll have to see about scheduling/budget.

Happy you found the way to extract the missing hps. I was lazy so I chose to bring more air with the pods instead of rejetting a size down. I agree that those little bikes kick ass.
last saturday, I managed to do my first wheeling with my ZR, and it was scary as shit. won't do it twice

loudhvx wrote: The discussion below does not really affect the Zr550, but I thought I'd post it for anyone interested, or on the odd chance someone can actually confirm the swap. As Tyrell mentioned, it definitely works with the 9.5:1 motors (-1121 pistons).

With many discussions on the Gpz550 forum, the one combination we have not confirmed was the Zx550A (3-groove marks) camshafts as a drop-in swap on a Kz550 D or H (81-83 gpz550) motor (-1127 pistons). Those motors, as mentioned, also have 10:1 compression, but the valve pockets are not as deep, and likely the dome is lower compared to the Zx550A (-1166 pistons).

But there is another factor involved, and that is the timing. The Zx550A has the intake camshaft advanced through the use of different holes on the intake sprocket. The sprocket is the same casting as all other Kz550 sprockets, but it has two extra holes drilled in what would otherwise be blank panels on the sprocket wall. One of the extra holes eliminates the Kz550 intake timing mark, you can probably get a decent estimate of where the mark would be.

So then the question becomes... does the piston need larger pockets because the cam duration is longer (maximum lobe lift is about the same or even a hair lower), or are the pockets larger to accommodate the change in timing?

Another question is, are both pockets indeed deeper? The intake likely is, but is the exhaust? Since there is a higher dome to make up volume lost in the intake pocket, does it just make the exhaust pocket look deeper, or is it actually deeper (than a Kz550 D/H gpz piston)? The Zx guys seem to stick with Zx motors and the Kz guys seem to stick with Kz motors, so no one has really done a very precise, side-by-side comparison, that I know of.

If the pockets are bigger due to the timing change, then it may be safe to use Zx550-Gpz cams in a KZ550-Gpz motor, as long as you use the standard Kz timing, which, if I recall, is what Corey recommends anyway... that is, using Zx550 cams but use Kz550 valve timing. I'd like him to confirm that, though.

I definitely think its the timing events that required Kawasaki to change the piston in the ZX motor. Max lift happens when the piston is way down in the hole. Piston valve issues happen around 10° either side of TDC when the piston is chasing the closing exhaust valve or the opening inlet valve catches the descending piston.
With the below results I believe i can run either timing setup on my engine, But the inlet cam piston valve clearance is marginal when set at the zx position and leaves no room for error regarding gasket thickness or block/head skimming.

With the ZX cams and sprockets fitted I checked them at both the ZX and KZ/ZR timing marks. These corresponded with Lou's finding on his excellent 550 camshaft web page. Other than the lobe centers on my engine being 1° earlier, which i put down to differences in chain/guide wear.
I also checked piston valve clearance using the 5 and 10 degree timing points indicated on a moriwaki 550 camshaft installation sheet which corresponded exactly at the points of minimum clearance.

Checks done on KZ550H1 motor, bare head with helper springs @ 0.050 lift zero lash
ZX CAMTIMING
INTAKE
open 21° BTDC
close 33° ABDC
234° duration
lobe center 96° ATDC

EXHAUST
open 41° BBDC
close 13° ATDC
234° Duration
lobe center 104° BTDC
LCA 100°

With the inlet cam moved to the KZ/ZR timing
open 13° BTDC
close 41° ABDC
lobe center 104° ATDC
LCA 104

Piston Valve clearance was done with a KZ550H1, used head gasket, bare head, valves installed on No.1, helper springs, 0.1mm valve lash and dial gauge
Moriwaki recommends 1.2mm for the inlet and 1.8-2.0mm for the exhaust

Inlet ZX timing PVC
5° ATDC 1.24mm
10° ATDC 1.18mm
15° ATDC 1.42mm

Inlet KZ/ZR timing PCV
5° ATDC 2.28mm
10° ATDC 2.15mm
15° ATDC 2.23mm

Exhaust PCV
5° BTDC 2.31mm
10° BTDC 2.17mm
15° BTDC 2.32mm

I can confirm you can drop a pair of ZX550 camshaft (1984 to 1989) in a 1983 GPZ550 or a 1992 ZR550 (identical engines).
I tested with the KZ/ZR sprockets and timing. the engine never failed, even bursted to 11500 rpm and in road race conditions.
I also tested these cams with the cruzinimage piston kit (613cc) and a grinded head mating surface (-0.10 mm) with the same positive results.
conclusion: you can use the 3 groves cams in KZ engines. keep in mind that for better results, you might want higher compression. when riding, the engine feels more powerful but with a flater response.

On a side note, ever since changing my ZX550 Intake Cam Timing from stock, to mirror that of the ZR/KZ 550 Intake Cam Timing, the fun factory has climbed the charts. Exhaust cam timing has remained the stock. A little less in the gas mileage, but loving how it runs, and accelerates. I would highly recommend this, and should have done it years ago.

Nice job Wozza!
Thanks for the confirmation Roy!

Thanks in general, Corey!

So maybe the Zx intake timing was for mileage or emissions? Either way, good to know it's an option on the Kz's, Zr's, and Kz- Gpz motors.

I will edit the Kz cams page when I get a chance.

Roy Batty wrote: I can confirm you can drop a pair of ZX550 camshaft (1984 to 1989) in a 1983 GPZ550 or a 1992 ZR550 (identical engines).
I tested with the KZ/ZR sprockets and timing. the engine never failed, even bursted to 11500 rpm and in road race conditions.
I also tested these cams with the cruzinimage piston kit (613cc) and a grinded head mating surface (-0.10 mm) with the same positive results.
conclusion: you can use the 3 groves cams in KZ engines. keep in mind that for better results, you might want higher compression. when riding, the engine feels more powerful but with a flater response.

Hi Roy, I notice you said the 1992 Zr550 motor was identical to the 83 gpz. (As discussed earlier) the Zr550B (Zephyr) actually has lower compression pistons than the Gpz motor. So did you actually install the Zx cams into a 83 Kz550H motor, or a 92 Zr550 motor, or both? ( I also noticed you said "the engine" implying this was only done on one engine, which is why I ask.)