Synthetic Oils

I would guess that this topic has been thrashed around here quite a bit, but I don't recall the discussion. Any thoughts on whether to use synthetics in KZs? I currently use Valvoline dino 20W-50 and change it at 1000 miles. My scoot has probably never seen a fake oil in its 29 years. Thanks.

I'll jump in.

My experience, and opinion is on an engine that hasn't been rebuilt, or has the original gaskets, run non-synth oil. I have found with my experience that synth oil on older gaskets and seals will tend to seep. Change the non-synth oil at least every 3000 miles or every 6 months whichever comes first.

I run 20w-50 non-synth oil all the time, in my oil-cooled engines.

Drop the oil pan, and see what's in there.

That's all I have to say about that.

It's up to you what you use, but here's my experience: I've owned my '77 KZ650-C1 since new. In the past I ran Castrol GTX. When Castrol changed the oil formula I began running Mobil-1 Racing 4T 10W40 (in 2006). I have a bit over 50,000 miles on my bike, the head has never been pulled, it has had no engine work, and there is zero smoke or leaks. I run my bike fairly hard, but I don't run it above 9,000 RPM (redline). If your bike doesn't leak synthetic oil will not make it leak. However, be sure to use MOTORCYCLE oil, not automotive Mobil-1 or you may experience clutch problems. Take a look at the info in the following links for additional data:

Racing 4T Oil

Here's an in depth motorcycle oil study performed by Amsoil:

Motorcycle Oil Comparison

I have been running rotella oil with good results. I've also seen that rotella has become popular with the 4 stroke mx guys on their 13,500 rpm 250F's that hold less than a qt of oil. Many of them feel that it is a great alternative to the very expensive racing synthetics.

BTW sweet bike, grumpy !

650ed wrote:

It's up to you what you use, but here's my experience: I've owned my '77 KZ650-C1 since new. In the past I ran Castrol GTX. When Castrol changed the oil formula I began running Mobil-1 Racing 4T 10W40 (in 2006). I have a bit over 50,000 miles on my bike, the head has never been pulled, it has had no engine work, and there is zero smoke or leaks. I run my bike fairly hard, but I don't run it above 9,000 RPM (redline). If your bike doesn't leak synthetic oil will not make it leak. However, be sure to use MOTORCYCLE oil, not automotive Mobil-1 or you may experience clutch problems. Take a look at the info in the following links for additional data:

Racing 4T Oil

Here's an in depth motorcycle oil study performed by Amsoil:

Motorcycle Oil Comparison

I use the same stuff, Castrol 4T motorcycle oil. The head and jugs have been of my bike and new gaskets installed. But no leaks so far, and the clutch likes so ill stick with it.

Thanks for the info guys and compliment mjg! Will keep thinking about this until my next oil change. Don't put many miles on the J, but the ones I do sure are fun ones!

You will be pleasantly surprised at how much easier it starts and the rpms com up with a full synth 5 or 10 w 40.

I've found over the past while that 20w50 is just overkill, and it makes for hard starts in the colder weather.

Guys have run these bikes through death valley in the summer with regular 10w40 and they have been perfectly fine, so unless you desert race, then you are fine with 40.

I use Rotella T 5w40 Full Synth. It has modifiers (like other good synth oils) that resist wear in diesel and flat tappet engines.

Just for information, I hooked up an oil temp gauge to the oil in the pan, and on my daily commuter in low to mid 40 degree F weather here in San Francisco, I'll get to work and the oil temp is 220-230F, with the stock GPz550 oil cooler. On the race bike in the heat of the summer I get 280-290F, and that's with a larger oil cooler. 20w-50 will work for any temp I care to ride in. Not dissing you TeK9Ne, just stating my experiences.

I couldn't imagine what the oil temps would be without a cooler.

Just remember to change it about every 6 months, as a rule. Moistues will get in there, and it collects in the pan, because water is heavier than oil. If you've never removed the pan, give it a look.

grumpy56 wrote:

I would guess that this topic has been thrashed around here quite a bit, but I don't recall the discussion. Any thoughts on whether to use synthetics in KZs? I currently use Valvoline dino 20W-50 and change it at 1000 miles. My scoot has probably never seen a fake oil in its 29 years. Thanks.

it is so nice it hurts my eyes...that , as i'm sure i've said already...ROCKS!!!!!

what are those in that kinda condition(if one could be found ) going for i would guess you watch em sometimes when they sell? just for kicks.......i never seem to see any on e-bay in 2010...

gosh that is my favorite....

oh....oil...yeah...20-50...change it all the time..10-40 works too..rottela and change it a lot....from what i read the rottella (sp) will be good enough...cheapo wal-mart too....chnage,change,change

2 more cents

Corey's bikes are shell bearing mains where as the big KZ/J are rollers.

Where you live & your particular riding conditions are what determine the frequency of oil changes.

There's a difference between living in the country and getting caught up in city traffic on hot summer days with air cooled motors.

That said, it's prudent to use that as part of your oil change interval formula.

Synthetic oils are outstanding IMO, as long as they're formulated for wet clutches.

Lastly, in these Japanese multi cylinder bikes, as well as many others, the oil also undergoes extra stress from transmission gears.

The one thing I prefer to do when switching from one type of oil to another is to pull the clutch pack, clean it and if possible, soak the friction plates in the new oil for an hour or so.

Which is best? Hell, there's no clear answer and even if there were, guys would debate it.

Where rebuilt engine break in is concerned, it's always the cams vs the valve buckets that problems surface. I've seen parts fail, even when good oil was used and the correct break in process was used. In every instance, it's been after market parts that fail.

Just My Observations from over 30 years of hands on experience with motorcycles...

Larry C

CoreyClough wrote:

I'll jump in.

My experience, and opinion is on an engine that hasn't been rebuilt, or has the original gaskets, run non-synth oil. I have found with my experience that synth oil on older gaskets and seals will tend to seep. Change the non-synth oil at least every 3000 miles or every 6 months whichever comes first.

I run 20w-50 non-synth oil all the time, in my oil-cooled engines.

Drop the oil pan, and see what's in there.

That's all I have to say about that.

+1

I purchased my KZ900 last May and immediately switched to Amsoil within a month (been Amsoil my whole life thanks to my Dad, who's been Amsoil since the company was founded). I started noticing oil seeping, especially around the valve cover gasket and cam end plugs (Got a set of billet plugs for the next valve adjustment). I'm pretty anal about keeping my toys nice and clean, so this isn't a major issue, Simple Green cleans the drippins' right up!

I live in the "Inland Empire" region of SoCal: this evening, it will do down to 40 degrees and tomorrow warm up to 75 or 80. In the summer, it "dips" to 60s and warms up to the +115's on occasion. So I'll gladly live with any oil seepage if I have the piece of mind of running a high quality [$$$$] fully synthetic oil.

FYI: I'm also running a stock 903cc engine without an oil cooler; and Amsoil 10W-40.

Rotella T 15-40 in my 82 KZ and my 86 Radian.Radian leaks or seeps nary a drop and uses no oil.KZ seeps from cam plug gasket even though I 've changed them twice.No oil useage.I gueess Big Daddy is just markin his turf.Both bikes have oil coolers and KZ has oil pressure gauge,oil temp gauge and cylinder head temp gauge.No problems with either bike o'heating even though in TN it gets both hot and very humid in the summer.Pans have been off both bikes and are always very clean. KZ runs a Schnitz racing oil pan valve to prevent oil pump starvation under hard accel.bj