Four engine questions '78 1000 A2

I have questions for all of the engine gurus. My bike is a 78 KZ1000 A2 and I am starting with a stock engine rebuild. So far I have determined that my bores, pistions, rings, and cams are all re-usable.

1) Should I worry about getting into my oil pump to check the clearances inside? Doesn't look like that gasket is in a rebuild set. Do the pumps ever give trouble?

2) My Clymer manual says that 20 links of the cam chain should measure less than 6.21" However there is no drawing to show you where to measure. What I mean to say is do they want you to measure from the far end of link #1 to the opposite end of link #20 or do you measure from the the front pin on #1 to the same side of the same pin on #20? Hope that makes sense. The chain looks new, and I can't detect any slop. It's measures longer than 6.21" if you use the first method that I described. Or do I just replace it? $40, cheap insurance.

3) My manual states that the carbon ridge at the top of the cylinder should not be removed if the original pistons and rings are being reused. Does this mean that I shouldn't hone the cylinders before I re-assemble? I would normally hone the cylinders on any other engine to break the glaze.

4) As I stated before, my clutch friction discs will need replacement, but I discovered extra plates in my clutch. Z-1e's website says 8 fiber discs and 7 steels for this bike. I have 10 fibers and 9 steels. Two of the steels are noticably different than the other 7, but all of the fibers look the same. So is it 8 or 10? I never got to ride the bike, but the clutch actuation was quite stiff. could this be due to the four extra discs putting more preload on the springs?

where the plates different colored and thin the extra plates i mean. if so it sounds like you may have a barnett clutch kit in the bike. if i'm installing new rings if the cylinders check out then i hone the glaze off if i'm reinstalling the old rings then i normally dont unless they are badly glazed. i normally would try to put in new rings unless you have measured the free gap and they check out fine. rings lose tension over time. so they can not seal as well as new rings. as far as measuring the cam goes i just normally replace but if you want to measure pick a 21 link section and measure from the center of the first one to the center of the 21st.that will give the 20 pin count that your looking for. i know it sounds strange but that is how it is done.if your topend looks good your oil pump should be fine. i reuse all the time.

1.check the pump for slop or grooves in gears or pump body
2.are you splitting the cases?if you are definately throw a new chain in there.dont forget the guides and rolers
3.is there a ridge on top of your cylinder?that suggests excessive wear to me anyway.measure pistons and bores

Thanks timebomb. Yes, the extra steels are copper colored and seemed thinner. I did measure the free gap and it is very close to the specs for new rings. I only need this motor to get through a year or so. I want to see how it runs as a stocker, and accumulate the needed parts to convert to 1075cc with mild cams and street ports. Cams looked good, and I will check out the head and valves this weekend.

PLUMMEN wrote:

1.check the pump for slop or grooves in gears or pump body
2.are you splitting the cases?if you are definately throw a new chain in there.dont forget the guides and rolers
3.is there a ridge on top of your cylinder?that suggests excessive wear to me anyway.measure pistons and bores

Thanks Plummen. Boy did I ever split the cases. The ridge, if you can call it that that does exhist is just carbon buildup. I carefully measured my bores and pistons. The results are in my build thread on page 9 IIRC. I'm thinking of doing the cam chian even if it is good. this would allow me to put the 1075 kit in later without splitting.

every time i have the topend off and split the case i replace the cam chain cheap insurance as far as i'm concerened if it just carbon don't worry about it scrape it off car cleaner eats carbon fast if the cylinder isn't glazedto badly then just clean it up nice and put it back together.if you hone it you will end up bereaking the rings in again. and just wearing the rings abit more. there by opening up the ring end gaps even more.

Why take it apart with the intention of putting it back together with the same used parts...if possible?

Work Smart - Not Hard

1- Leak test it

2- Manually turn the motor over with the valve cover removed to inspect cam chain for stretched spots.

3 - If it's got the extra plate clutch kit in it, the damage may have already been done to the basket. Inspect the fingers for grooves / ridges. Those clutches are no good on street bikes, especialy a stock motor. The stock clutchs is the best clutch you're ever going to find for a street ride.

or a race bike as well

larrycavan wrote:

Why take it apart with the intention of putting it back together with the same used parts...if possible?

Work Smart - Not Hard

1- Leak test it

2- Manually turn the motor over with the valve cover removed to inspect cam chain for stretched spots.

3 - If it's got the extra plate clutch kit in it, the damage may have already been done to the basket. Inspect the fingers for grooves / ridges. Those clutches are no good on street bikes, especialy a stock motor. The stock clutchs is the best clutch you're ever going to find for a street ride.

I took it apart for two reasons.
1) I needed to replace the crankshaft. The alternator rotor had spun, and I was advised by other members that the only permanent solution was to replace the crank and rotor.

2) I wanted to. I like to tinker, its a hobby. I wanted to make sure that there were no foreign bodies in the crankcase or combustion chambers. The bike had been sitting outside for 15 years. I'm also prepping for a later 1075cc kit with mild cams and port work. Wanted to make sure that the lower end was all good, so that I can simply pop off the head and jugs without getting any further into the motor at that time.

I'm sure you'll want know, why not do the 1075cc now? Well I never got to ride the bike stock, and would like to know how much improvement I get. I'm also spending considerable time and effort and about all my money to build and paint the bike.

Ok...now I see where you're coming from

larrycavan wrote:

Why take it apart with the intention of putting it back together with the same used parts...if possible?

Work Smart - Not Hard

1- Leak test it

2- Manually turn the motor over with the valve cover removed to inspect cam chain for stretched spots.

3 - If it's got the extra plate clutch kit in it, the damage may have already been done to the basket. Inspect the fingers for grooves / ridges. Those clutches are no good on street bikes, especialy a stock motor. The stock clutchs is the best clutch you're ever going to find for a street ride.

So what keeps the new chain from strectching as well? I think mine is stretchedddd, and so is the drive chain. ??????? Do I just keep tensioning the new one until it stops stretching? And then what do I got? A need for yet another chain? ?? Do they just keep stretching then finally break or what?

I think that all of these type of chains stretch over time. But compairing the drive chain to the cam chain is apples to oranges. The cam chain has to turn about 5 lbs. worth of camshafts, and it lives in a sealed environment, bathed in oil. The drive chain has to pull a 525 lb. bike with a 200 lb. rider and it is bathed in roadgrime, grit, and only gets lubricated 1/3 as often as it should. Cam chains should last considerably longer than drive chains.