Synthetic or Conventional oil?

Hey all,

Sorry if this has been discussed already but I was curious what you guys go with in your KZ's, conventional or synthetic oil?

I was just about to change my oil and bought Castrol Syntec (sp?), before i actualy run synthetic in this old girl I figured I should consult the panel I don't know if it is pointless in these old bikes or if it is a good thing. I know you all will know though! Please share your thoughts ... thanks!

I haven't run synthetic in my bike. The problem seems to be that sythetic seems to increase the likelihood of leaks in these old bikes. Or if you have some leaks it has been known to make them worse.

Some people have problems with it, some have no problems at all. I have like 3 leaks on my bike already, so I'm just going to stay away.

The conventional wisdom is to stay with conventional. :whistle:

synthetic will make your clutch jump, jiggle, and possibly slip under load (hp), too much additives will also make the clutch jump as well, remember these ol bikes have wet clutches and they depend on the dino oil to grab and operate properly.

i run shell rottela disel oil (15w 40) because it has the highest nickle and phosphat rating of any oil out there, it also has more anti wear additives that tend to clog catalitic converters.

BTW captain morgan and coke makes my grammer/spelling bad, i dont think nickle and phosphate are the right words eather.

Interesting story on this topic.

Yesterday a guy that was think about selling his pristine 85 GPz750 Turbo brought it over for GPzInfested (my nephew) to check out (as he wanted to buy it). I was talking with him while GPzInfested was taking the bike for a test ride, and he said a couple of things that I found notable.
(1) He bought the bike new and has always run Mobil 1 in the bike since break in.

(2) He uses Barnett clutchs in the bike and he is on the third one (after the original, that's four clutchs).

(3) The bike has 18,000 miles on it.

He claims the bike has so much power the clutch can't handle it (also claimed the bike will do 180 mph, and it's stock without Race Mode enabled), so I don't really believe he knows what he's talking about.

But it seems to me there might be a connection between the short lifespan of the clutch and the type of oil he uses.

Until recently I have always used Castrol 10W40 with great success. However, I have read numerous articles about passenger car oils having reduced the zinc and phosphorus levels in their products because of emission system concerns. This has lead to the destruction or increased wear on cams in many high performance engines that use solid lifters. So, being the cautious type, I have switched to Mobil 1 Racing 4T 10W40 oil. It has higher zinc/phosphorus levels than car oils along with other properties that would seem to benefit KZ engines. (see links below) and it is made specifically to be used with wet clutches. I've been using it for 1,000 miles now with good results (no leaks, no clutch slip, no smoke, etc. although I didn't have those problems with Castrol either.) My bike even seems to run a little smoother, but that's probably all in my head resulting from the cost of the oil.

www.mobil1.com/USA-English/MotorOil/Oils...acing_4T_10W-40.aspx

www.mobil1.com/USA-English/MotorOil/Oils..._Oil_FAQs.aspx#FAQs2

I've been running Mobil 1 15-50 for about ten years now, no problems, no slipping clutch, no oil leaks, and a cooler running motor. It did post it's fastest et (11.68) at the drag strip while on syn, and have backed that up with the race cars also. The cars run 13s, 12s, and 11s respectivly and by just changing the rearend lube to syn. they all dropped 2 tenths af a second, which is huge for a $20 investment. Changing the cars to syn in the engine didn't make a noticable diff. It appeared to us that the stronger molecules of the syn. made a bigger diff. on the high shear loads of the gears, than the loads incountered in the engine. So much harder to tell on the bike as et depends sooooo much on launch, and it can vary 2 tenths from run to run on any given day, but it ran all it's fastest mph's (114-115)(mph & et don't always go hand in hand)with the syn. I run a temp gauge in the oil sump on the bike and the oil runs about 15 degrees hotter with syn. confirming that the syn. transfers heat better than dino oil, but it takes much more heat (I don't remember how much) before breaking down. The extra lubracating of the syn. can help to offset the reduction of lubracating metals in the new oils. And the price diff. is less than it used to be, syn. hasn't gone up nearly as much as dino. plus longer change intervals. As far as Steell's guy, I've seen people (my brothers' one) that are just hard on bikes, jack rabbit starts with lots of clutch slipping are the norm, so don't be to quick to blame the oil. And no, I don't work for any oil co. or sell oil of any kind:laugh: just sharing what I've learned over the years with first hand experiance.

This not a doubled post, but I've posted pretty much the same info several times, in different threads.

I've been running AMS Oil 10W40 since the early 80's in all my bikes. They all run quieter and smoother and shift better because of it. None of my Japanese bikes leak. Some, like my KZ900, haven't tasted dino oil in 27 years. No problem with clutches.

I really agree with Z1R rider about rear ends just switching to synthetic gear lube produced a noticeable improvement in power in my KZ1300.

KZCSI

Post edited by: KZCSI, at: 2007/09/01 11:16

I think it all depends on how much effort you've put into the bike.

Personally, I think '76 KZ900 is the least sophisticated machine I have and think standard oil is more than adequate... BUT I might see things different if I were to sink a few thousand into the motor.

As far as the clutch, I assume the manufacturers will be able to tell us of the friction material their now using will support it. I belong to a ZX10 group and there are folks that have been running synthetic since break-in time and have 30 to 40k on the original clutch -- so there can be benefit.

I knew I could on you guys for some good info and you came through. Good arguments for both sides.

I think I may try that Mobile 1 650ed mentioned. My motor is freshly built with all new gaskets so if it springs a leak out of no where that will help me judge for next time i change the oil. My clutch is brand new so I can use it as a gauge as to how many miles I get out of the clutch using synthetic.

If your motor is fresh, be sure to break it in with dino oil first. The rings will never seat if you use syn on a new or rebuilt motor.

steell wrote:

Interesting story on this topic.

Yesterday a guy that was think about selling his pristine 85 GPz750 Turbo brought it over for GPzInfested (my nephew) to check out (as he wanted to buy it). I was talking with him while GPzInfested was taking the bike for a test ride, and he said a couple of things that I found notable.
(1) He bought the bike new and has always run Mobil 1 in the bike since break in.

(2) He uses Barnett clutchs in the bike and he is on the third one (after the original, that's four clutchs).

(3) The bike has 18,000 miles on it.

He claims the bike has so much power the clutch can't handle it (also claimed the bike will do 180 mph, and it's stock without Race Mode enabled), so I don't really believe he knows what he's talking about.

But it seems to me there might be a connection between the short lifespan of the clutch and the type of oil he uses.

Sounds iffy. And tor those in the know you should only ever use genuine Kawasaki friction plates in the turbos. Barnett clutch plates tend to break fibers off which end up destroying the turbo bearings.

Z1R rider wrote:

If your motor is fresh, be sure to break it in with dino oil first. The rings will never seat if you use syn on a new or rebuilt motor.

Very true.

BTW I just use a good quality mineral oil in my turbo, whatever happens to be on offer at the time of buying. I do not run fully synth at all. I do change the oil and filter regularly though at about 1500-2000 mile intervals depending on use.