Big Bore Z1

Carbs look like 28mm. from 74-75 with drains in float bowls, not threaded cap style 73's. Definitely not the 26mm. Miks that 76 came with. My guess on the pipe is RC Eng. or maybe early V&H, but it's not a Kerker. Without sleeves the largest bore in for 903 barrel was 1045cc. according to Wiseco, with sleeves I've had 1200 cc. motors.

Stock battery is okay.

Dyna green 3 ohm coils.

28 mm Mikuni carbs from earlier year Z1
(oem KZ900 had 26mm)

Empty hole under sprocket cover access cap looks like where earlier year chain oil pump was attached.

What's engine i.d.#? Thinking maybe from an earlier Z1, perhaps 1974 which had unpainted engine, and chain oil pump wasn't used on 1975 Z1.

Thought is was Kerker exhaust, until seeing Jack's post, and see it doesn't have the typical Kerker bend in the can.

Good Fortune!

Thanks for the replies guys. So for the chain oil pump... it was only used on 74 and earlier? I dont remember the whole engine code but it started in Z1E-..... can I bolt up the sprocket cover and that would be okay? Also, considering that these are probably 28mm mikuni's which pod filter size works on these?

Cheers,

Kyle

Kyle_w11 wrote:

Thanks for the replies guys. So for the chain oil pump... it was only used on 74 and earlier? I dont remember the whole engine code but it started in Z1E-..... can I bolt up the sprocket cover and that would be okay? Also, considering that these are probably 28mm mikuni's which pod filter size works on these?

Cheers,

Kyle

Non-chain-oiler models don't have the hole. The chain oiler drive went through the hole, and as I recall engaged a fitting built into end of the countershaft sprocket shaft.

For peace of mind, would fashion a cover to bolt over the chain pump drive hole, to keep any crud from getting inside.

"Z1" was made only three years, being 1973, 1974 and 1975.

In 1976, it became KZ900.

Good Fortune!

Kyle_w11 wrote:

...considering that these are probably 28mm mikuni's which pod filter size works on these?....

Pods for any year Z1 should fit.

Another option would be an KZ900 air box, or maybe a Z1 airbox as carried by Z1E --- but would first check with Z1E to see whether fitment of Z1 air box would be feasible on KZ900.

Good Fortune!

Click on these links for some info about pods and airbox.

www.z1enterprises.com/detail.aspx?ID=2670

kzzone.com/carbs.html

www.z1enterprises.com/detail.aspx?ID=2671

www.z1enterprises.com/detail.aspx?ID=220

Good Fortune!

What should the compression be on a big bore? I guess it depends on what's been done to the head huh...

Looks like an old Carpenter pipe.

and it has a GS1100 swing arm.

The shock mounting is a little sketchy. It should have clevis type lower mounts on the shocks, the type that straddle both sides of the lug on the swingarm. How close is the shock to the chain ?

Good eye on the clevis mount! I didnt see that and I am nervous about it too.. i'll look into other options for the setup.

Here's a little update, I'll try to get some pics up later.. i've got most of the missing parts together and i see the first startup in 27 years in sight.. I am just waiting on an oil filter assembly and two front sprocket cover bolts. it still baffles me as to how some of the parts that I have had to source, were actually missing. There was no oil drain plug. there was no oil filter assembly. All bolts were missing from the starter cover and front sprocket cover.. all of those are pretty distinctive and definitely valuable stuff.. anyway.. it's almost all together now.. I pray that this thing starts when I get it all together!