z1 - how to adjust slotted cam gears?

Hi guys,

To start out...
I'm not asking about finding the cam lobe centers with a degree wheel. I'm purely asking how to turn the cam within the cam gear...

Getting the cams set up on my 74 Z1, and have a quick question about how to adjust my slotted cam gears.

See image. (1 and 4 at TDC).
Everything is already set up and tightened down.
Blue thread loctite on cam gear bolts.

I'm now thinking I maybe want to advance the intake 1 degree, and retard the exhaust 1 degree, compared to where they're currently sitting in the image.

Is there any way to do this without having to remove the cams again from the bike?
For example...
Can I loosen the 3 cam sprocket bolts, and then somehow move the cam a little bit while its still all assembled on the bike?
Or will that basically not work, and I need to pull the cam out and do it on the work bench?

Sorry if this is a stupid question.
How do you guys normally do it?

thanks,
Ed

When you loosen the cam gear mounting bolts, the cam may want to jump (rotate slightly one way or the other, if it is not in a stable position), so make sure you have a mark from cam gear to camshaft, so you can get it back to where it started.

It seems like it would be easier to rotate the crank, and let the camshaft sit where it wants to be naturally, then use your mark to tell where it is relative to where it was.

What cam sprockets are those?

I bought the cam sprockets from dynoman performance.

They're the dynoman brand. They're pretty nice.
Have all the necessary markings on them including the 28th pin mark.
$70

www.dynomanperformance.com/engine/cam-sprkts.html#kawa

I think omr probably has a how to video on here someplace.

After looking at the pic of your cams I looked at a pic of my
GPz750 cams timed correctly look at the exh. lobe compared
to yours.

Actually, his (emy111) timing looks right. I don't know how different a gpz750 would be, but here is a thread for a KZ750, and it's timing looks very similar to the original poster's photo. The 750 manual I have shows the bolt closer to 12 o'clock, which would put the exhaust lobe further down, at about 9 o'clock. (That is also how the 550's look. )

www.kzrider.com/forum/2-engine/189116-re...nt&type=raw&start=20

In your photo, Dave, can you see the timing mark for the EX? I can't make it out. Maybe the gpz750 has a really advanced exhaust cam, but I doubt it would be by 30 degrees?

loudhvx wrote: Actually, his timing looks pretty close. I don't how different a gpz750 would be, but here is a thread for a KZ750, and it's timing looks very similar to the original poster's photo. It also looks like how the 550's look.

www.kzrider.com/forum/2-engine/189116-re...nt&type=raw&start=20

In your photo, Dave, can you see the timing mark for the EX? I can't make it out. Also the mounting bolt for the camshaft looks to be too far advanced, but maybe the gpz750 has a really advanced exhaust cam?

I was gonna say my 650 is like that in my manual and in practice too so was thinking maybe the GPZ is different and advanced much more ?? ..... wanted a second opinion to be sure first though since I don't have a pic and am going by memory.

I edited my reply after remembering I have a 750 Clymer manual.

The 550's, and I assumed the 650's and early 750's, have symmetric valve timing, so the lobes, for a given cylinder, should really look like mirror images of each other when that cylinder's piston is set at TDC. The ZX bikes started to have asymmetric timing, but it was only by about 4 cam degrees or so. Dave's picture looks like the exhaust cam is about 20 to 30 deg of cam rotation advanced.

I downloaded a factory manual for the KZ/ZX 750. It shows all cam timing is symmetrical, so the cam lobes should mirror each other at TDC. The ZX750 cam timing is different from the KZ750, but it's still symmetric (unlike the Zx550).

loosen cam sprocket bolts and move motor a touch, 1 degree of cam is very little (0.5 degrees of crank rotation)

Beware of a compressed valve spring whacking the cam around against the loosened bolts - I ruined one megacycle cam doing that.

Dialling-in extra overlap can work for rpm power, albeit 2 degrees, the issue with slotted cams isn't so much how to set it but what to set it at.

1 degree of cam rotation is 2 degrees of crank rotation.