Engine fitment

Ok, I may be jumping the gun on my build. I purchased a 1981 J model 1000 for my 1978 KZ 1000 frame, it doesn't look like it will work to me. Any thoughts or advice?

Why do you think it won't work ?

Being a novice at bike building...after some more thought and measures it looks like it will be okay. Does PDM on here still do business? I tried contacting but haven't gotten a response yet.

I would think Zed1015 would be your best source of advice

Ref PDM Les Holt hasn't been on the forum for a good while but that doesn't mean he ain't working, StreetfighterKZ I believe you know Les well, is he still taking work on ??

Wookie58 wrote:

Why do you think it won't work ?
 

My impression is that with the introduction of the "J" motor in 1981 the motor mounts were changed to add rubber dampers. I've never tried to do this swap, but I'm guessing it's not a direct bolt-in swap.

As far as I know, all of the "big four" engines (Z1, kz900/1000) made from 1973 to 1980 use the same motor mounts and should bolt directly into any frame from 1973 to 1980.

Swapping across that 1980/1981 dividing line is where things get more complicated. Someone else will have to chime in with how complicated.

The J/GPZ motor into the earlier frame has been done tons of times.
Upper rear mount is the same location as is the upper front.
Upper front mount will need spacers as it is narrower ( replace the rubber upper mounts inserts with solid aluminium bobbins )..
Once installed on those mounts you will see where the J engines lower front mounts differ from the Z frames lower mid mounts which will be redundant and where the new lower front mounts with a cross tube for the J need fabricating . 
It's been over 30 years since i did one of these as well as a GPZ1100 motor into a Z650 frame and it slips my mind whether the lower rear mount lines up too for the 1000 frame or whether it needs extending out to meet the engine. 

The 1000J and GPZ1000/1100 will fit but you have to made an extra engine mount to the frame for the engine case rubber damper.

 
 
 

Good info guys thanks. I feel better about proceeding with this engine!

It's not a project without a bit of "fab" 

Wookie58 wrote:

It's not a project without a bit of "fab" 

I've come to realize that and accepting.