ZR750 oil lines and pan on a kz650?

Has anyone tried a Zephyr ZR750 oil pan, oil lines, oil cooler on their kz650?
It looks like the ZR750 engine is missing the lower mounting points of the kz650 crankcase casting, so I'm uncertain whether the ZR750 oil lines will fit.
I'm using the Zephyr oil pan and cooler, but have put together oil lines from a GPZ.

Zephyr 750 oil pan fits KZ650 and there is no issue with oil lines of Zephyr 750 oil cooler: there is still a gap between oil lines and crankcase.

Zephyr 750 and KZ650 oil pans to compare:

Do you live in a particularly hot climate? I ask because a KZ650 wouldn't normally need an oil cooler except maybe for a racing application. If you do run an oil cooler you should consider installing a thermostat to ensure the engine reaches and maintains an appropriate operating temperature, otherwise you may end up with condensation in the oil. Ed

weeZee: Sorry, looks like I misguided you. I have two sets of Zephyr coolers and lines. One of them is installed on my KZ650 project bike as a model and yet another one (which is in perfect condition) lies in box and wait to be installed on finished bike. I took lines from that newer set and checked: the line that to be mount to lower oil pan port fits without issue but line for upper port couldn't be installed until its first bent aren't slightly unbent.

However it's simple to do. All you need is old 7mm bolt (or some rod of same diameter), valises and bare hands.

Do you live in a particularly hot climate? I ask because a KZ650 wouldn't normally need an oil cooler except maybe for a racing application. If you do run an oil cooler you should consider installing a thermostat to ensure the engine reaches and maintains an appropriate operating temperature, otherwise you may end up with condensation in the oil. Ed

Our climate is continental, we have quite severe winters and warm summers. However, all three of my air cooled "inline four" motorcycles (Kawasaki Zephyr 750 and two projects based on Yamaha XJ600 51J and Honda CB750 RC42 engines) equipped with factory oil coolers . I also registered no issues with condensation in oil not for all my mostly 100K km experience with Zephyr 750 nor during tens of thousands of kilometres on other air cooled bikes. Lot of that kilometres I rode when temperature was less than 10C or even slightly below 0C.

On the other hand, oil cooler is mighty useful in tight city traffic and when days are really hot. I definitely never have had an issue with overheat, even when one of rides on Zephyr ended up with hole burnt in one of pistons.

gazzz wrote: [quote

On the other hand, oil cooler is mighty useful in tight city traffic and when days are really hot. I definitely never have had an issue with overheat, even when one of rides on Zephyr ended up with hole burnt in one of pistons.[/quote]

You've got it. The oil cooler is not for cooling the engine, is for removing the heat from the clutch.

And how does the oil cooler know which is clutch oil and which is the rest of the oil? It cools the oil it doesn't know where it came from?

weeZee wrote: It looks like the ZR750 engine is missing the lower mounting points of the kz650 crankcase casting, so I'm uncertain whether the ZR750 oil lines will fit.
I'm using the Zephyr oil pan and cooler, but have put together oil lines from a GPZ.

I'm confused by the highlighted sentence. Could you explain further?

And for what it's worth, I added a cooler to my 750 and the bike runs great. I think the pan came from a ZR-7 and the cooler/lines from a 700A. The lines fit perfectly. The only part that wasn't a straight bolt-on was mounting the cooler itself.

I'm confused by the highlighted sentence. Could you explain further?

I have only this old photo to illustrate what weeZee said. As you may see, unlikely to KZ650 and KZ750 Zephyr 750 crankcase has only one front mount, on upper half of case.

Interesting the pan would still fit.
Steve

Interesting the pan would still fit

In fact Zephyr 750 engine is direct descendant of KZ650-750 engines. Quite a number of parts in KZ-Zephyr engines have same part numbers (including oil pump and secondary shaft) , other are compatible, like camshafts, oil pan, clutch, ignition and alternator covers and so on. Even kick starter mechanism from KZ650 could be transplanted into Zephyr engine.

The kz650 and the zr750 use more or less the same crankcase casting, however while the kz has four mounting points at the front of the engine, the zephyr does not have the lower mounts. This removes a lip or flange from the zr case and the oil lines might not clear this lip on the kz cases.
As to whether the bike needs an oil cooler, I have a oil temperature filler cap on the crankcase and regularly note the engine going north of 90 degree C on hot days in traffic. Once the oil is over 50-60, it should drive off water condensate, but once it is over 90-100 it's cooking all those fancy additives and shortening the life of the oil. As the smaller zr550/750 bikes are pretty much a direct descendent of the kz650/750/550, I reckon the engineers would have added the oil coolers for this reason.
Thanks for the plumbing tip, seems I'll have to do the same when the hoses arrive.

Does that make sense?