TOPIC:

I am in need of camshaft cap #1 for a 78KZ1000A2. I cannot locate a part # so I do not know if caps off other engines will fit. My son and I were putting the engine back together and we did not have the cap lined up w/ the ridge on the camshaft and broke it. Can anyone help out with either the part or a part number or let me know if a cap off some other engines will fit. Alternatively it looks like the two halves could be installed seperately and still do what they are supposed to do. Is that a good or bad idea if I cannot find another cap? If you have the part or number please email me at This email address is being protected from spambots. You need JavaScript enabled to view it.

thx

The caps are ground to match the cylinder head. There is no part number other than the complete head which is 11002-024-2H which lists for $836.69. However I've seen guys have the parts welded back together and even though a used cap would not be an exact match, my guess is it would work fine. I think any Z1, KZ900 or KZ1000 cap from 1973 to 80 should work if you can find a junk engine.
78kz100a2 wrote:

I am in need of camshaft cap #1 for a 78KZ1000A2. I cannot locate a part # so I do not know if caps off other engines will fit. My son and I were putting the engine back together and we did not have the cap lined up w/ the ridge on the camshaft and broke it. Can anyone help out with either the part or a part number or let me know if a cap off some other engines will fit. Alternatively it looks like the two halves could be installed seperately and still do what they are supposed to do. Is that a good or bad idea if I cannot find another cap? If you have the part or number please email me at This email address is being protected from spambots. You need JavaScript enabled to view it.

thx

It's not the diameter of the bore that's a problem, so much as the axial alignment of the cap.

No matter what you do, in order to fix it correctly, you're going to have to pull the head.

Viewing this as an opportunity you might:
1)Find a good used 'J' model head and reap the benefit of larger valves. AFAIK, no machine shop work required but it will require some modifications and additional parts. APEJay should chime in here and tell you what you'll need
2)Find a good used cap, remove valves, install with new bearings on that cam, as close to zero clearance as you can get, torque both caps down evenly with the cam in place but without the guide pins on the replacement cap, take it to the machine shop and bore some holes for alternative guide pins. Put it back together with these 'new' pins leaving the old ones out. Use bearings that give the proper clearance. You may need to have your camshaft ground.
This will give you the opportunity to check your valve springs, valve guides, replace the guide seals, and lap the valves if they need it. Something you should probably do anyway while you have the head off.
3)Find a good used, or rebuilt 'matching' head.

Personally, I would go with option '1'.

-Duck

Thanks for the info. I just invested a bunch in the head(new valves, guides, retainers, springs etc.), new pistons (1075 kit) so if I could fix the cap or find a replacement I would prefer that direction.

I searched the Archives and found the following:



kzrider.com/forum/viewthread.php?tid=26702
kzrider.com/forum/viewthread.php?tid=23998
kzrider.com/forum/viewthread.php?tid=20677
kzrider.com/forum/viewthread.php?tid=16852
kzrider.com/forum/viewthread.php?tid=8258

In that case, I suggest talking to your machine shop guy to see if he has any caps kicking around and what he recommends for getting it aligned.
I suspect you'll be real close to factory spec with new guide pins if care is taken in locating them. There might be room to use solid pins near the bolts. I'm not looking at a head right now so can't say for sure. If there is, once aligned, drilled and reamed for the pins you can tap the top of the hole for a keeper screw as insurance that they stay in their holes.

I haven't done this, just thinking through what I'd do if I needed to use a foreign cap.

Maybe a post to the parts wanted classifieds here if your machine shop guy doesn't have one.
you might also ask on dragbike.com forums to see if anyone there has other suggestions and their classifieds for the cap.

-Duck

The reason you have the cut outs and cam end plugs in a cylinder head is that they are line bored right through that cut out. Call local bike shops and ask where they get their work done. There will likely be only one or perhaps two shops in your area that do ALL the cycle machine work. This guy will be able to fix the broken cam cap. He may choose to weld or just use another cap and line bore it again.

I suggest you post your bike model/year and location in your signature as I know machinists in different parts of the country.

If you had a BIG box of cam caps, you would have a decent chance of finding the correct clearance. You need to buy some stuff called plastigage (or plastigauge?). I have heard from a fella who has a zillion caps that he has had some luck just measuring and then trying his variety of cam caps.

plastigages are indespensible for measuring clearances in areas where a feeler guage can't go. Just lay a strip on the camshaft bearing surface, install the cap, torque to specs, DO NOT ROTATE THE CAM, remove cap, and measure how much the plastigage "spread". Auto mechanics use them when measuring tolerances on connecting rods and crankshaft caps.

I havnt had a problem running (other enemy caps) but may just be lucky. Ive heard tell where an enemy cap will chew through the block in seconds, be in bed with your wife before the frame has a chance to seperate from the motor. If youve ever watched one real close you cant help but see they vibrate in place, distant snarling sounds are heard. Seriuosly though, id bolt the cam in with a different cap (dont let it bite your fingers off)! without the springs and wiggle the cam on each end, go from there. These bearing set ups are virtually indistructable. (Dont forget to wear safety glasses as they have been known to attach to your head and proceed to suck your brain out).

I've swapped cam caps between heads a few times and never had a problem with alignment.

I've been search for a # 3 cap for a while now with no luck. I hate to give up on this haed but if you want I'll sell the #1 to you.let me know

here is short thread from dragbike forum
www.dragbike.com/forum/forum_posts.asp?TID=3132