CVK Keihin conversion for old Zeddies

[Gosling1]

OK here are some photos from the work today.....

1st shot - these are the 2 plastic T-pieces. The OEM RX is on the right, its now 10mm shorter in overall width than it needs to be. The FCR spare is on the left. Its 20mm longer than the RX piece.....

I had to take 10mm off the tapered end, and replicate the small O-ring grooves. Also had to take the taper off and turn it back into a circular cross-section so it would fit into the body of the carby properly. Careful use of the angle grinder soon took care of the taper and the 2 O-ring grooves !!






Here is the ghetto lathe with the T-piece inserted in the chuck and the young bloke pulling the trigger.......I slced off the end, removed the taper - and cut 2 O-ring grooves. Working plastic is pretty easy






Here is a pic of the new inlet manifold stubs bolted up to the motor.....





Rubber manifold boots fitted......






and finally - 36mm Keihin CVK semi-flat slides fitted. These are the same style of carbies used on ZRX's......I am really looking forward to seeing how they go on the old 77 Z1000.



Filled the bowls with fuel and a temporary fuel tank (funnel ) - gave it a kick in the guts and after a few winds - she burped into life Happy about that I was. Throttle is not hanging either on the shut-down, so it looks like there are no air-leaks around the new alloy manifold stubs or the inlet rubbers.......

Sounded fine, good response considering that the jetting is just a shot in the dark. Need to spend some time with the manometer now and get the butterflies balanced properly - with all the dicking around today with the throttle-shaft adjustments etc - the balance is a bit out. Not a whole lot but it needs to be sorted. I intend to keep these carbies on now and get them working 100% so this old girl may even get a run at Brett's dyno I am sure he will be stoked at another old bike going in there .......

[J.B]

Nice work!

I've got a mate who's been wanting to fit a set of these to his KZ for a while now. I'm sure he'll be mighty interested to see the results

[Gosling1]

time for an update .....

despite spending far too much time sorting out KTM electrics - I have put an hour or 2 into this job, as I need a bike for winter and the 77 Z1000 is the one.

Got the tank fitted today and after a few small teething issues - had the bike started and idling nicely with the 36mm CVK's.

So decided to saddle up and go for a quick spin around the block - just to make sure everything was working properly.....

well FMD. The carbies work way better than I expected. They give the old 2-valver a nice smooth power curve down low, but still work really well when you give it some stick.....really well

The smoothness of the response is what blows me away. The carbs are essentially the same as what you find on much later model kawasaki models - even up to the ZZR1100/1200 motors, ZX6R and ZX9 motors. These all used a carbie much the same as the GPZ1000RX. To have these fitted to an old 2-valve motor is a massive improvement over the old-school 26mm Mikuni slide carbs. I still need to balance these CVK's - but given how easily the bike starts and idles with these carbs fitted - I am not sure how much of an improvement will be gained with a balance. They seem pretty good straight off the bat.

I will be taking the Zeddie for an inspection shortly, maybe even this week. Updates will be done on the dedicated thread to this bike, this thread is more about the carbie conversion only. JB - if your mate wants some more info on the conversion, just let me know.

[J.B]

I'll have a chat with him next week. I'll have a set of carbs handy by then too so he might just start twitching