Cam Timing Rabbit Hole. Seems I fell in.

1982 kz550a
11k on odo
New to me, less than 100 miles ago.

This started as "I'm gunna clean my carbs this weekend" because they've always operated rather; how's the manual say? "blubbery". Basically, you cannot start the engine without 100% full choke and then after several miles of riding, the engine would die unless you kept about 90% choke. After 20-30 minutes of riding you _may_ be able to flip the choke off but it's a crap shoot if the engine dies on releasing the throttle OR races out of control at a stop light - to the point where I let the clutch out and try to choke the RPM down, or flip neutral and reach under the tank and twist the idle stop... neither is good; right?

So carbs coming out for some cleaning and new jets/gaskets/seals. I figured since I was going this far, why not pop off the valve cover and peek? What harm can that do? It's nice to have a baseline of knowledge/condition of your ur bike when it's an unknown.

Here's where that pesky rabbit hole opened up and I fell in.

I read the Clymer manual tirelessly over the past week to become more familiar with my kz550a.
I know that both camshafts will have to align and the ignition's timing mark too, assuming I have to pull the cams for shim adjustment.
Problem is, I cannot for the life of me (endlessly spinning a 17mm socket on the crank) get the alignment marks to align as the Clymer manual states they should.

Pictures will be coming shortly but that's my dilemma. The exhaust cam gear alignment mark never appears (at forward case edge) when the aft intake gear's alignment mark does. Rotating the engine multiple times to confirm.
What's up with that?
How can this be?
Are there aftermarket cams that won't follow this procedure?

Ultimately, I did this so I could confirm my valve lash and here's what I measured:
Cyl 1 thru 4 Exhaust:
.15-.20 / .25 / .20 / .15

Cyl 1 thru 4 Intake:
.15 / .20-.25 / .15 / .20

These readings seem to be all over the place. Honestly, I was expecting them to be close to identical on side. These readings seem to be close enough the manual spec's but some are at/over top allowance so I want to adjust them back down.
BUT
Dare I take the camshafts out? Ack! I don't know what to do? I still need to determine what shims are present so I can order the appropriate replacements.
Suddenly carb cleaning seems like a cake walk...

Is there light at the end of this tunnel and is it an oncoming train? Enquiring minds wish to know...

Thanks for any insight you can provide.

Take the plugs out if you haven't. It goes a lot easier without compression.

Also you may want to perform the high idle control mod for the 550. This enable you to independently control high idle speed under full choke. Also check and see if you still have choke flaps. Search for 550 links of member Loudhvx

R

The intake cam timing is not done by aligning a mark with the deck. It is done by counting links on the chain. The mark should be close to aligning when the valve cover is in place. But with the cover off, the mark will only line up if you simulate some slack in the chain between the cams.

There is a link in my signature on cam timing. You should read it and especially the warning.

There are also links to the factory manuals. You should download all of them.

TDC is the T mark not F. Clymer manuals can lead you into that hole. Follow loud's advice.
Steve

Thanks guys!

I did read many of loud's posts/links previously and was aware of the cam chain tensioner issue. I actually thought that may have been something that happened previously when I noticed the manual (came with the bike) had many grease/oil stains on the valve check/adjust pages.

At any rate, I went back and looked and counted the cam chain links and the gear alignment marks do in fact work out exactly as stated - between the 43rd and 44th back from exhaust alignment. So all is good. Totally makes sense now that I think about the valve cover having the chain guide built-in and depressing the chain downward between the two gears. :blush:

So I guess all is good. No rabbit hole to crawl out of and the light at the end of the tunnel is not an on-coming train!
BUT
What do y'all think of these valve gaps?
Should I bother or are they close enough to say let it go for now?
I read earlier here on the forum that since the shims only come in .05 increments, it was sufficient to measure only to that (which basically skips the "round up" part of the equation stated in the manual. This is why some measures state ".20-.25" (#2 intake above). .20mm slipped thru but .25mm did not. So it's in there somewhere but the manual states .20mm as the high-end for tolerance.

This bike was a gift from my son (who is a Harley fan himself) as I've always had an old KZ or GS kickin' around the shop since he was a kid. So I want to keep it in good shape, "forever".

Very nice looking bike.
Technically, you could probably leave most of the shims as is. The only question is #2 intake. Are you measuring with the crank at the T mark, as described in the factory manual? Measuring at different points in the rotation, such as having the lobe pointing directly away from the bucket, may alter the measurement.

The manual describes using the 1-4 T mark for the inlet valves in pairs #1 and #3, or #2 and #4 (rotate the crank a full turn to do the other pair). Then use the 2-3 T mark for the exhaust valves (same thing, measure #1 and #3 or #2 and #4, then rotate crank a full turn for the other pair).

Uh Oh...
Don't tell me this Clymer manual isn't worth the paper it was printed on?
Dang it!

What I did (3 times before I could muster the courage to actually unbolt the camshafts) was to rotate the crank until each individual lobe was pointing directly away from it's lifter and measured there. I did note that in several crank positions multiple lobes were pointing away enough and so I tried taking readings there but I found the measurements were sometimes different from my "lobe base" measures...

Interestingly or aggravatingly as the case is, upon getting to the actual shims, I found none of them had their sizes printed on them anywhere. I was expecting to see something inked or stamped on it's perimeter but not one of them has any identifying marks. I have Vernier calipers and even an older micrometer but nothing that measured in metric. So it was an hour of measuring the shims with the micrometer and then converting to metric. Ugh. I shoulda' listened more in school. :blush:

I found that the valve gaps that were most "off" (#2 intake most obvious) were thinner shims than other cylinders had. Additionally, the shims look ... old and worn.

So ultimately, if the method I followed to measure these gaps was accurate enough to proceed (my fingers are crossed tightly) then I need to buy 6 shims - 2.55, 2.50, 2.50, 2.45, 2.55 and 2.45 to get these all back into the tune-up specifications table 3 listed in the Clymer manual.

For my day off, it has been pretty gratifying (assuming I didn't screw-up BIG by following this questionable manual?). I also managed to strip down the carbs and expected to clean them, but it turns out the PO musta' been one of the good guys that took care of this neat little bike. Every carb bowl, jet, needle et cetera was clean and bright. So I'm really hoping that much of that "blubbery" engine behavior is valve adjustment or possibly some timing.

Now it's time to hunt-down some shims...

BEFORE.


AFTER:


CAMS, LIFTERS, SHIMS:

Make sure none of the parts gets mixed. The buckets seem interchangeable, but they don't always like to be swapped.

The Clymer method is ok, but it's not as consistent. A caliper is not always good enough to measure shims. It's better to use a mic (as you did). Shims are not always exactly .05 increments. Some are little thicker or thinner.

If you are calculating for new shims instead of using the factory method (as you now have it all apart), then I suggest aiming for the middle of the range.

Judging by the shim thicknesses you need, that motor has low miles. Most 550's came with 2.50/2.55/2.60 shims to start with.

The Clymers manual specifies the WRONG method on how to position the cams. You should position the cams per the Kawasaki method since this routine placed two adjacent valves on the base circle at the same time. When you point the cam away from the valve, like Clymers says to do, the adjacent valve will be depressed thus skewing the cam away from the valve within the journal clearance. Net result is the Clymers method will suggest there is more clearance than there actually is.

One tip that may help you, I know it did for me,...when you go to install the cams back into the engine first thing to do is set the crank to align the 1-4 T mark to the indicator. Next, remove the cap on the cam chain tensioner and make sure the wedge piece is pulled back so the tensioner can move in and out (the wedge keeps the tensioner from moving backwards). Then you can install the cams per the manual specs. Verify carefully and then install the valve cover back. Last thing to do is reinstall the camshaft tensioner wedge, spring and cap. You need to wait until the valve cover is installed to do this or you will over tension the chain with the rub block in the cover.

EDIT: just saw that WARNING website page! Great minds think alike it seems!

Good luck

Hmmm?

Well, I'm in no real rush to slam this thing back together... Do you think it would be better to reassemble and measure the gaps again using the factory service manual method?
I'd rather not screw up the bike if this Clymer's method is inaccurate.

Also. Any recommendations on where to buy the shims?

BTW. I did keep all the lifters (and everything else I removed) ordered and numbered so everything including the bolts even, goes right back to where it came from. I thought I was just OCD about this kinda' thing. LOL

jetsrus.com/valve/valve_shims.html
Steve

Z1 Enterprises sells shims too.

I'd measure the gaps properly. Those .25's will go down some and may even fall in spec, and the .15's will move closer to the .10 bottom.