J motor Fitment

We are now fitting the J motor and just a couple issues. I have tried search on this matter but can't find any information. It looks like I have to remove the lower engine mounting tabs on the frame to be able to get the rear mount to align on the J motor. Has anyone done this swap?

Could it be you have swapped the LEFT/RIGHT upper engine mounts???

 

You will also need to add front lower mounts

According to this picture you don't really need the lower or bottom engine mounts...



This is a reinforced KZ650 frame that zed1015 built into a lightweight racer.

Build thread here - z1ownersclub.co.uk/phpBB3/viewtopic.php?f=7&t=14312&start=30

A drag bike frame builder also told me the most important engine mounting points for any KZ are the rear case mounts, that is where all the power and twisting is transmitted from the chain and sprocket.

When I put my Z1 engine into my 650 frame I made extra thick rear upper mount mount plates to replace the thin stock ones and gusseted the mount under the front sprocket.

Injected wrote:

According to this picture you don't really need the lower or bottom engine mounts...

This is a reinforced KZ650 frame that zed1015 built into a lightweight racer.


 

I'm going to disagree with you on this one !!  Zed's bike is a modified 750Zephyr frame (as per previous BOTM feature) but also it uses a "pre-"J" motor. The "J" uses the three points in green (doesn't have a rear lower case mount) and the earlier motor uses the three points in red. If you could get hold of the cross member with the mounts from any "J" motored bike it would make things easier and stiffen the frame. See attached pic of Lee's "J" powered 650 and the three motor mount locations

My mistake, I thought they had a rear lower thru mount. Nothing a little welding and fab could not solve, the shop where those pics were taken looks pretty capable.

 

Rob what am I missing ? - I don't see how you could use the same three points as your bike when the "J" motor doesn't have anywhere to attach the "lower rear" mounting point to ?????





 

Wookie58 wrote:

Rob what am I missing ? - I don't see how you could use the same three points as your bike when the "J" motor doesn't have anywhere to attach the "lower rear" mounting point to ?????

 

Forget my previous ( now deleted ) ramblings.
It was the result of a very rare brain fart which mixed up the details of both J motor into Z frame and vice versa  .

The soild bush conversion for the front mounts is still recommended though.


 

You completely confused me with that one buddy (not difficult) having been intimate with my "K" for nearly 3 years now you put me in a "tailspin" - how much more vibration do you get with the solid mounts ?

wrote:

You completely confused me with that one buddy (not difficult) having been intimate with my "K" for nearly 3 years now you put me in a "tailspin" - how much more vibration do you get with the solid mounts ?


 

Not sure about a 1000 but my '82 750 engine I converted from rubber mount to solid mount vibrates about the same as a stock 650 bumped up to 831cc, hardly noticeable.

I thought the J1000 might have had the rear lower mounts recessed like the front lower ones, that is the way they have them on the later 750's (just thought I could not see them in the pics)

Wookie58 wrote:

- how much more vibration do you get with the solid mounts ?

It's not noticable, just the same as a normal Z.