yet another oil question

[cpark_12]

should i use fully synthetic or semi synthetic oil? i plan on getting some lucas 10w 40, but don't know which to get. this will be the 1st time i use synthetic or semi if that matters. also, what are the pros and cons of both? thanks

[H-2 CHARLIE]

im going fully syn. castrol r-4 superbike real soon it will be my first on the 600 kat iv seen a few bad reports on lucas motorcycle oils but you cant beat fresh oil

[hardlydangerous]

There is no reason Not to use a synthetic

Most of the stories people have heard over the years are nothing more then myths.

The only one I know of that is true is... if you have an oil leak on a higher mileage engine. OR its useing a lot of oil. It will leak and often do use more oil. The fix is simple.. change the seal or gasket.
The reason synthetics can cause a engine with a very minor oil leak to leak more is because sludge and crud build up around seals and gaskets from years of using mineral oil can slow or block the leaks. Esters and other additives in Synthetics actually clean your engine as you drive/ride and these deposits and sludge build up will be cleaned away and a damaged seal or gasket that has a leak slowed by deposits may start to leak more. As for using more oil.. Synthetics are much more stable at all temps and have better flow and migration then conventional oil. Again with the deposits, ring lands carboned up and valve stem seal gunked up can be slowing oil flow past the rings and seals. once the deposits are cleaned away the engine may start to use more oil.

If your engine is in decent shape and was maintained well you should never have any issues..

I highly recommend a full synthetic and recommend one that contains no mineral oils
Redline, Amsoil, Royal Purple Are among the best of the best.
Mobil 1 is said to be a group IV or V synthetic but a freind requested the MSDS sheets and said it states it contains mineral oil.
but regardless if they contain mineral oil or not Mobil 1, Motul and even Castrol are better them most of the other syntheticsand much better then semi synthetics
The less heat, friction and mineral oil and byproducts in your oil the better. Your engine, trans, and clutch will thank you in the long run.
Sure some will use an conventional oil all their life and never have an issue... think about this..
Why is it so many Harley owners rebuild there engines so often? Is it because they use the cheap brand name Harley oil?
Why is it you ask a katana owner or other sport or cruiser owners how many miles you can get before a rebuild and they tell you something like 60,000 or something like that.
That is proof that there is people having issues with thier current conventional oils and mineral based 100% synthetic oils.

So how does a conventional oil reduce engine life?? well this is just 1 of MANY ways.
The friction pates are porous and are squeezed during engagement. When spinning, the oil oozes thru the material to the surface where it dissipates heat and reduces ware. An over heated clutch will over heat the oil. The heat will oxidize byproducts in petroleum oil that will form a glaze on the fiber plates. This reduces the porosity of the friction material, which restricts the flow of oil. With less oil flow there is less cooling and more heat and more oxidization and more glaze. A glazed clutch is referred to as a burnt clutch, Once the glaze starts the clutch won’t last long.
The heat from the slippage will cause the steal plates to bend and warp and wear unevenly. Warped plates only contact each other at the high spots and ware away friction material. Bits of this friction material flows thru your transmission and engine like little cutting tools wearing on the gears, cyclinders, rings and bearings. Not fun, but what can you do.

First thing is to use a 100% synthetic lubricant that has no byproducts that will oxidize Amsoil Redline and Royal purple contain no byproducts or petroleum products that will cause clutch glazing. Besides nearly eliminating clutch wear and glazing you transmission and engine will run cooler, last much longer and improve fuel economy and performance

How can you tell if the engine is suffering any damage?
The easiest way is the oil sight window.. how fast does you new oil turn black. How does it smell after a hard run?
This is often just one way mechanics can tell when an engine has been running quality synthetics and for how long. If you can put 3~5000 km and ther oil is still transparent and looks like syrup you know its not suffering bad blow by or burning the oil or deposits floating through the engine.

FWIW I'll toss is an Amsoil testamony here.
One of my good friends has a KLR650. After setting up his bike with the lowest possible gearing he could and changing the sprockets he called me up so we could head out on the trails for a nice day's ride to test out his new set up. After several hours we were on our way home and stopped to take a leak and that's when he noticed his KLR leaking oil like crazy from around the skid plate. I quickly found the problem. Turns he had forgot to tighten the front sprocket nut and this allowed the sprocket and seal bushing to slide out of the countershaft seal and thus causing all the engine oil to be pumped out. We found a hose clamp among our tool kits and attached it to the end of the counter shaft to keep the sprocket in place as a "get me home fix" We rode the hour or so back and parked the bike in my shop and checked it over. We drained the remaining oil to check for any metal that would show signs of damage. We only managed to drain about 150ml of oil out of the engine!
This engine had run for at least 1 hour with out oil. Who knows how long before that? No oil shavings were found in the oil.
We pulled the valve cover to check the cam/valve buckets for wear and everything was in good shape including the compression. The edges of the cam were a little stained from the heat but everything was fine and still within’ specs. The bike is still running strong a years later and has well over 65,000 miles

[ICEG]

full synthetic

[ctandc]

Oil threads ALL over this sight, just search. Most come down to personal preference.

Me personally I use Mobil 1 full synthetic 15w-50 (no friction modifiers, works fine with wet clutch) for @$20 for gallon jug at Wallyworld....use Suzuki filters.

No complaints in almost 10K miles.

[quik89Kat]

amsoil in all my bikes ...Just dont use a car synthetic it is not designed for wet clutch use..

I have also used rotella and delvac(sp) diesel truck oil as it works with a wet clutch
harleys need constant rebuilds because of there poor v-twin engine design not because of the oil ...the degree's at which the cylinders face puts lots of stress on the bearings ...also the way the carbs are set-up isnt a great design either ,ask any harley tech

harley is stuck on nostalgia if they change something too much people get ****y

[katman05]

I use Motul semi synthetic, just a question of choice.

[darrell3535]

I didnt see any mention of Repsol full synthetic...hopefully that is good quality as I have been running it for the last 2 oil changes / 6K miles.

[hardlydangerous]

I've never seen Repsol on a shelf here in Canada

Oddly enough the Repsol sponsored bikes don't run repsol oil.
I was talking with a tech at Mosport last year and they said they run thier own blend of oils but would not say what kind it was. From what I did get out of our little talk it sounded as though they run 1 l of 20w-50 in with there 10w-40

[The CyberPoet]

Some additional comments to the original poster:
- Make sure you get an oil rated for the bike -- no using oils intended for modern cars (No using API SM rated oils for example, nor any oil marked "energy conserving" in the lower half of the API ring) -- specifically look for the JASO-MA (or the newer JASO-MA2) rating specifically on the oil as your assurance that it's right for the Kat's needs.

Mobil 1 is said to be a group IV or V synthetic but a freind requested the MSDS sheets and said it states it contains mineral oil.

Although I agree with you on 98% of stuff, this is the kind of intentional misinformation I would attribute to someone who pushes Amsoil motorcycle products heavily as a distributor/dealer...

Every oil company on the planet has different formulations for different markets. For example, Castrol R4 is different in the USA than it is in the UK, and both of those are different from their Australian version. Without being able to see the version of the MSDS your friend supposedly looked at, I can't comment directly about it, but I do know that Mobil 1 motorcycle oils are 100% synthetic in the USA (see Mobil 1 Racing 4T 10w-40 MSDS (RTF/Word Doc) and Mobil 1 V-Twin 20w-50 MSDS (RTF/Word Doc)), and according to their engineers, in all of North America, Western Europe & Australia/New Zealand as well.

On the other hand, RoyalPurple's own oil engineers have told me over the phone that their products are based on Group IV oil stocks purchased from other companies and then blended with their custom additive package, whihc does make them a PAO synthetic basis. I doubt that has changed in the last 18 - 24 months since I last talked to them, but it definitely was the case. However, I am still disturbed by their website data claim that "Max-Cycle exceeds API/JASO new warranty requirements" without specifically listing a JASO class (JASO-MA1, JASO-MA2, JASO-MB, etc), and their lack of additional technical data (I expect flash temp at minimum, which is why I had called their engineers the last time I spoke with them, to get that and the HTHS values).

Cheers,
=-= The CyberPoet

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