A right old 650 / 750 Mess

[Royalratch]

Guys.

Got my frame and motor back today all psyched about putting it together. Have a nice new Stainless bolt kit to mount the engine too.

To my horror, my freshly rebuilt engine and powder coated frame don't seem to fit together.

The main culprit is the upper front engine mounting is miles out from the frame brackets. Its much narrower than on my 650?

The thing is, I don't even know if the motor is a 650 or 750 as it was built from a bunch of stuff - pretty sure the frame is a 650 tho.

I thought these things were all freely interchangeable?

Have I just screwed myself? As I'll need very wide spacers to get it all to fit. The bolt kit also looks like some bolts aren't long enough etc.

[pertonpc]

Hi Ratch

Some 650s used two separate shorter bolts for the upper front engine mounts - rather than the one long bolt. The bolts fit with the heads to the inside & there is a cut out in the crankcase to hold the head captive.
Perhaps this could help you out ??

[Charlie]

The Z650 and Z/GPZ750 lumps should be a straight interchange anyway. The engine outer is basically the same. Aside from cosmetics and a different cam cover, only the bore size really changed

The top front mounts are secured by two triangular mounting plates from the frame.

They secure to the engine casing with a bolt from the inside of the engine case as previously described (or they do on mine at least) and two bolts then bolt to the frame downtube.

Just where exactly is your gap wrong ?

[Royalratch]

This is n;t my issue to bud.

As I said, the front engine 'loop' that accept the bolts is much narrower than on the frame - so whatever bolt I put in the frame mounts is miles away from the engine mounts meaning 2 massive spacers are needed.

[Charlie]

Can you add a photo of the offending area ? I am still struggling to understand where it can be out on a Z650/750 motor and a Z650/750 frame.

I will add the same area photo's/measurements from mine. That way we can perhaps get to the bottom of it.

[zed1015]

You have used the later style cases (gpz etc) that had rubber bushed front mounts .
Been a while since i played with the little motors but i think the lower front mounts are also narrower if remember correctly.

[garyd]

Rubber mounting was my first thought too.

Are the holes initially very big...i.e. to fit a rubber sleeve into?

[Royalratch]

The green areas show how far off the frame brackets are from the engine brackets. They;re miles away? So confused. On my 650 the engine goes all the way upto the frame?

[KWACKERZ1]

https://www.kawasakiepc.com/SystemSearc ... N=65306424

Have a look at this there appears to be collars for the engine mount, you can look at all parts fiches here.

[KWACKERZ1]

Or here
http://www.cmsnl.com/kawasaki-1982-kz75 ... ml#results

But I can only see the top mounts not the lower ones,

What model crank cases are yours the engine number prefix may help determine the model then you can look at the frame mountings for that bike.

[oldtimer]

I dont suppose it is a ZR750 zephyr engine (KZ750 on the serial number) if so you may need these spacers.

http://www.kawasakioriginalparts.com/ka ... 1996&ca=GB

[Royalratch]

What model crank cases are yours the engine number prefix may help determine the model then you can look at the frame mountings for that bike.

Thanks for reply dude.

But this is whats so frustrating? There shouldn't be any differences between motors and frames on air cooled 650-750...?

[oldtimer]

I think we are thinking along the same lines KWACKERZ1.

[Royalratch]

I'll get motor and frame numbers up later today and hopefully you guys can tell me what they are?

The engine started life as a GPZ750 but may have had case swaps because of damage - I left that to the builder as all I wanted was the head / cams.

The frame I'm certain is a 650 - I think an SR?

[KWACKERZ1]

looking at your engine cases the casting holes look large and designed to accept the rubber bushes, I think once you have some installed in the cases you'll then be able to assess the gap properly.