KZ650 Touring Build

I bought this bike as a roller for $200 in 2015. This is what I started with :



Not the best pic (its from the sale add) but I got everything shown except the motor and tail/side covers... I also got the kick start lever, all the motor mounts/bolts, and the clocks. 

It is a early 77 B1 frame modified to accept C1 wheels/brakes/swing arm. I had most of the parts to make it a complete bike in my spares bins so this is how it started.

A couple of weeks after I brought this home I found a used 1982 Vetter Quicksilver fairing without the mount frame for $40 local to me. This is how the touring idea started.



It took me a while (2 years) but I eventually found some used 1980's? Shoei hard bags local to me for $40.



I got the bag frame mocked up on the bike and welded up a luggage rack using that frame as a base.



I also found a NOS Vetter mount kit for the 650 on Ebay for $80. I attached dual Fiamm horns.



I had some off road mountain bike LED lights I had fabricated years ago and used those as running lights under the fairing.



I used some replica MK2 turn signals on all 4 corners, on the rear I mounted them like a KZP.



At first I installed a stock KZ650 engine and rode it for a few days, but after years of riding a 831cc version I just needed more power
After searching locally in 2018 I quickly found a 1982 KZ750 Spectre engine complete for $160. Upon picking up the engine the guy also sold me a spare head and barrel for another $20!





Fast forward to 2024 and I have only put about 130 miles on the freshened 750 conversion (shaft drive to chain drive) and am still working on this bike to improve it. The Spectre is a mild cam version of the GPZ engine and is rated at 78HP to the crank. I adapted some CVK34 carbs from a 1990 750 Ninja and it has a stock exhaust system from a F2 KZ650.



The bike as it sits right now has used Progressive rear shocks and I just added a small oil cooler. I also painted the tank late last Summer.

I just pulled it out to get it running again to ride to my annual swap meet in mid June. I will update with some new pics when I get a chance.
 

Very nice, will serve you well,good job. I have a 78 KZ650 C 

That bike is begging for a cross-country adventure 

Those Vetter Quicksilver fairings are supposed to work pretty well. I have a paint matched one for the 81' Suzuki GS 1100E. Same scenario, no main frame mount but needs a windscreen. It does have both pocket covers.

My fairing came with decent pocket covers but I wanted something that would lock. Vetter did make locking covers for this model but they are very rare. I ended up making my own locking covers out of 1/4" thick ABS sheet and some hardware store locks.









They work good and no issues with them yet.

My wind screen is a bit scratched but not too bad, I do have a NOS replacement in a box when I get some time to change it.


 

The engine runs a little hot, so I added a small oil cooler last Summer using a modified KZ650 oil pan. The mounting was a issue due to the fairing, running lights, and dual horns.
I ended up mounting it off to the points side utilizing the upper front engine mount bolts.







I fabricated a stone guard which I installed today.

I also rebuild the clutch pucks and swapped out the oil pump for a tight low mileage KZ650 unit.



I did get around to painting the tank the same 1970's GM light metallic blue color as the rest of the body work.



Hopefully I will get it started back up tomorrow.



 

A true hybrid.  Very cool.

 

The only issue I had with the newer 750 engine was the wedge style auto cam chain tensioner. It failed and cause me to bend two valves because of some chain slack when it did not operate correctly. I ended up modifying the stock unit but it is really bulky and ugly. It was hampering me when trying to take the float bowls off one day. I ended up machining my own smaller manual tensioner to replace it.





You can see here just how big that stock unit was.





Lots of room under there now.
 

I installed my finished rock screen for the low sitting oil cooler.





The screen has 1/4" holes in it so I backed it up with a fine mesh screen just to be on the safe side. It was the only decent screen the metal place had in stock. I am running 3/8" rubber GM spec transmission cooler line with -6AN barbed hose ends.

I also put some thru holes in the back of the bracket behind the cooler.



Today I am getting ready to start it after replacing the oil pump. I had a low hot oil pressure reading a couple of years ago so I replaced the pump. I put a pressure gauge and a thermometer on the fitting for the main oil line in the lower case.





Before I fire it up I will cycle the crank with the starter and the plugs out to be sure oil pressure is good and oil gets up to the cams.





Hopefully this solves the low hot oil pressure issue.


 

I put some gas thru the carbs and had a pretty big leak on #2 float bowl, pretty sure its a gasket O ring pinch. Hopefully easy to fix, I do have spare gaskets somewhere if necessary.

Decided to start it with the auxiliary gas tank petcock shut. Put it on choke and it started right up.

At 2000 RPM cold the pressure gauge read 55 PSI, a good sign.

Ran the engine till it starved of gas to make it easier to remove #2 float bowl, will probably get on that tomorrow.

Only slight issue was a pinhole leak on the oil cooler at the back bottom. Not quite sure what to do about that.


 

I ordered a small oil cooler as a backup, it will be here tomorrow. That cooler on there now was given to me but I was unaware there were any issues with it. Funny that I modified it to get the AN fittings on there but that is not where the leak is

The new cooler will require a angle bracket to be fabricated for it to be assembled. I may also need to make a new rock screen, TBD.

I never really trusted that cooler, the way I had the fittings in it was a bit weak. The new cooler will have more robust fitting adapters that I can put some trust into.
 

The fuel leak was a pinched gasket O ring, had a spare so put it in and got it sealed. The engine is running good, swapped from 112.5 to 110 main jets when I dropped all the float bowls.

I got a chance to do that hot oil pressure test, the changes I did improved the oil pressure number by +6 PSI, but its still on the low end at 23 PSI @ 4K RPM. The range I saw in the 750 manual was 28-36 PSI. The only other thing it could be is worn crank bearings so might have to think about splitting the cases one day.



The picture is a bit shaky, sort of needed 3 hands.

That oil cooler is still leaking, during that test is leaked about 2 teaspoons so it needs to be taken off. I have that other cooler and have been seeing what it needs to mount it.