1978 KZ650 Bike Build

cases from a z650 f4 version also fitted on z750 models:)

DoctoRot wrote: Wow that must have taken a serious hit. Looks like there are many more cracks, possibly some you cannot see. might be better to cut your losses on those.

Yep. Saw that one. The case is a mess and I'm considering my alternatives. I only have about $400 into this project and should be able to recover that much from the parts.

I do not think it is from a z650 F4 or z750s, but could certainly be wrong on that. I say so due to the location of the shift pattern is located. On all the 650 and 750s I have seen (in person or pic of said) have the shift pattern behind the shift shaft, while the pics show this in front of the shift shaft. I am still not sure what they are from. Have done some search on line and have seen several that look very much like them, but they have Kawasaki on them. Appear to be from police 1000s.

DOHC wrote: I agree. Not a 77/78 kz1000.

My guess is they are a 79/80 mk2 kz1000 covers. The 81 and later J model had an added undercut.

I’m in agreement here. There was a lot of 1979 kz1000 stuff in the lot I purchased. I’m saying there are not KZ650 covers. Thanks for the input.

HRM sorry to take away from your post. I wish they were something you could have used.

Mikaw wrote:

DOHC wrote: I agree. Not a 77/78 kz1000.

My guess is they are a 79/80 mk2 kz1000 covers. The 81 and later J model had an added undercut.

I’m in agreement here. There was a lot of 1979 kz1000 stuff in the lot I purchased. I’m saying there are not KZ650 covers. Thanks for the input.

HRM sorry to take away from your post. I wish they were something you could have used.

No worries! Some more work on the bike today. Slow going and lots of impact pounding. The PO managed to damage every single screw head on the bike. I guess they don't teach JIS in mechanics school.

I’ve been seeing 650 engines all over the net cheep, cheep!. Might want to weigh the cost to get a different engine...

Yep. Cases seem to be really cheap...less than $100. But you don't know what you've got til you get it. Photos are useful but not good enough to see everything. I'm trying to pull the drive out of its case...one more buggered up screw to go. Looks like I'll need a complete set of JIS screws to replace all the ones the PO ruined with his Phillips drivers.

I finally managed to get the screws out holding the main drive chain, thus releasing the crankshaft as well. After cleaning the case a bit I started looking for other signs of damage or repairs. Here is what I found.

This photo shows the seal location at the end of the crankcase. Looks like the end was welded up and then new grooves were cut into the weld. You can see voids in the weld on the inner groove. You can also clearly see the joint on the case face.


This photo shows the flip side of the previous one. You can clearly see where a piece had broken out and was replaced by weld.


This photo shows the opposite side, where the case was welded and a crack remains on the flange.


This photo shows the crack from the previous photo on the case itself. There is a very fine line showing where the case is cracked.


This photo shows the opposite side of the case to the first photo. Notice how the PO used permatex to help "seal" the end seal, but he used too much and the lube hole is partly obstructed.

I applaud your cleaning efforts, but I am afraid it is a futile effort. Those cases are only the value of aluminum salvage rates at this point. A very clear example to all reading this of what is NOT ACCEPTABLE in repair methods.

Skidmark wrote: I applaud your cleaning efforts, but I am afraid it is a futile effort. Those cases are only the value of aluminum salvage rates at this point. A very clear example to all reading this of what is NOT ACCEPTABLE in repair methods.

Precisely what I was pointing out.

OK...a little update. After discovering even more damage to the cases I decided to scrap them and try to find some better ones. 650 cases are pretty cheap on ebay but with only photos to go by it's tough to know the dirty little secrets. Nevertheless I think I found some from a '78 bike...same as mine. They were already vapour blasted, and the seller had 100% satisfied record (but so do a lot of scammers) so I took a chance and bought them. They should be here within a couple of weeks, along with the new tail piece.

Meanwhile I've been examining all the engine components. When I bought the project the PO said he had replaced three clutch friction plates that were cracked. Today I took the clutch apart and....found a broken clutch plate. Talk about dirty! It took me an hour and a full can of carb cleaner to get the dirt and grime off the clutch housing. He also said he replaced the con rod journals, and I was debating leaving them alone, but now I guess I'll have to take them apart and check them.

By the way...a couple of questions for those who know the 650. Are the fork uppers the same size as a Z1? And is the triple tree the same? If you don't know then can someone measure the diameter of the upper forks? I want to use a spare set of Z1 forks but if the won't fit the triple tree then I may need to buy a Z1 one.

Just jumped in on your thread Hardrock and it looks like we are in the same boat for sure, you have a few advantages over me in being in the state and not on a rock in the middle of the west Atlantic.. at least you inners are ok right and just the cases and covers to be sourced but that frame though.. ill be keeping an eye on how this turns out.