why is everyone saying stay away from synthetic oils

[Mr_RPM]

so im aware of synthetic motorcycle oils could cause clutch slippage on our old machines. I havent had any problems running synthetic in my stock 110.
well i recently got an old part made by powroll so i went to their site for siggles and ghits and found some reading on oil.

Oil. A good quality motorcycle oil is even more important after the engine is modified. Synthetic oils are absolutely not recommended in air-cooled four strokes with bigger cams. Change oil on modified engines even more frequently than their stock counterparts.

ummmm why?

Use a high quality motorcycle oil and change it often (about every 20 hours for the average rider, after every race for performance engines). Lack of quality lubrication will ruin an engine, fast! Four strokes with replaceable/cleanable oil filters need to have these maintained also. Powroll has found that only MOTORCYCLE oils (Hondaline, Yamalube, Torco, Powroll brand, etc.) are able to withstand the pounding a clutch and tranny deliver. Powroll does not recommend Synthetic oils for most four stroke applications (they're fine for two strokes)
again why?

someone know why synthetic oil on a engine with a bigger cam would be a problem?
i have ran all sorts of synthetic oils with no problem.
and your basic motorcycle yamalube for 4 strokes has a synthetic blend.
so its used every time you run yamalube (i know alot of people who use it)
why the hate on synthetics other than clutch problems?

i also know your not supposed to break in engines with synthetic oil because of glazing problems.

anyone know why for any of this?

[fabiodriven]

Sorry I don't know too many details, but I like synthetic in bikes. Small engines run hot and work hard (especially with me at the helm:naughty:) and I think synthetic oils are better in that application.

In my cars and trucks I use diesel oils since they have removed a lot of the good qualities of the oils in an automotive application. If I had to use a non-bike oil in a bike, I would use 15w-40 diesel oil. That's just me though.

[Mr_RPM]

so i did some further looking and found this:

WHY NOT SYNTHETIC?
Every test I've seen shows synthetic holds up longer than petroleum. Why don't you recommend it?
If you run your engine for extended periods without changing the oil, synthetic is probably the best choice.
However, the one thing that seems to keep engines healthy is frequent oil changes.
If you are changing the oil after a weekend of riding or racing, you aren't using this benefit of synthetic.
Petroleum oil seems to have an advantage over synthetic in how it sticks to the metal, and protects metal to metal contact areas better.
This is especially helpful in older style four strokes where you have many of high pressure metal-to-metal contact areas - cam and rockers, cam and head, etc.
No matter what oil you run, changing it frequently will keep your engine running longer.

also found some sweet atc 90 parts lol : http://www.powroll.com/P_HONDA_90EARLY.htm

i have even run yamalube full synthetic and could tell a difference on how smooth it shifted.
but maybe on my 110 now that im building it up ill just stick with GN4, synthetic or not i plan on changing it alot since i get oil free alot of the time.

here check out the whole site: http://www.powroll.com/tech_specs_OIL.htm. i found what they said about small engines interesting

[Grizzlypeg]

There's no reason a synthetic oil would be any more problematic for a 4 stroke bike engine than any other automotive oil. The key point is friction reducing additives. They can interfere with clutch operation. A synthetic rated JASO-MA is approved by the Japanese Automotive industry for use in wet clutch motorcycles and does not contain friction reducers that will impair clutch function. Synthetic oils are not that different from refined oils. They simply contain a more homogenous blend of oil molecules of similar length, making them more resistant to break down and viscosity change. Molecularly, the synthetic oil is made up of the same constituents as conventional oil, it is simply that it is more engineered to produce the ideal molecular length, rather than simply refining and blending various constituents. It is not made of a different substance, its carbon atoms strung together just like conventional oil. Synthetic oils are synthesized from natural petroleum components, but through synthesis, rather than refining, they can be made more ideal and the mixture more homogenous and ideal. Whether a suitable synthetic is worth it or not is another question. Me, I just buy a quality conventional oil and change it at manufacturor specified intervals or sooner (unless the application is for some reason more extreme than conventional oils can handle / Indiannapolis 500 for instance).

[Mr_RPM]

so running these motorcycle specific synthetic oils shouldn't be a problem.
i originally planned on breaking in on GN4 then using the honda 10-30 for the colder half of the year and the yamaha 15-50 for the hotter half.

[atc350xer]

I didn't know it was so high tech... I buy my oil at the mini mart :lol:

[Grizzlypeg]

That's interesting that they say not to use synthetic oil for 4 stokes, specifically with high lift cams. Non-roller cams rely on dry film lubricants and not the oil itself for lubrication between the cam lobe and lifter. The pressure at the point of contact exceeds what splashed oil can lubricate. They used to use zinc compounds (zinc disuphide), something STP was enhanced with for dry film lubricant. I seem to recall that zinc lubricant content has been curtailed owing to some other problem. Perhaps due to emmissions or oxygen sensors. Not sure.

Does you engine have a high lift cam?

[Mr_RPM]

That's interesting that they say not to use synthetic oil for 4 stokes, specifically with high lift cams. Non-roller cams rely on dry film lubricants and not the oil itself for lubrication between the cam lobe and lifter. The pressure at the point of contact exceeds what splashed oil can lubricate. They used to use zinc compounds (zinc disuphide), something STP was enhanced with for dry film lubricant. I seem to recall that zinc lubricant content has been curtailed owing to some other problem. Perhaps due to emmissions or oxygen sensors. Not sure.

Does you engine have a high lift cam?

yep, high lift cam, high comp piston, the works. building it now and gonna have it together in the next week or so. this is a 84 110 btw
got new rockers, new HD valve springs....ummm trying to think what else might effect the oil. ummmm new ebc clutch. lol
im just wondering about the 2 oils i posted after breaking it in with normal oil.
i have used synthetics on a 400ex with a stage 2 hot cam.

my father was telling my all this synthetic scare is not with the new synthetic Motorcycle oils made today like the ones i posted. and powroll did say their testings are old.
but my dad is just a motorcycle mechanic not an oil specialist or a race engine builder specialist.

[NINJA]

my father was telling my all this synthetic scare is not with the new synthetic Motorcycle oils made today like the ones i posted. and powroll did say their testings are old.
but my dad is just a motorcycle mechanic not an oil specialist or a race engine builder specialist.

Your father would know, automobile engines don't even come close to the performance output of a motorcycle engine nor are their engines near as advanced. BTW I'm "just a motorcycle mechanic" too.

[Mr_RPM]

haha its just hard to trust him all the time because i live with him and see him build alot of stuff and sometimes see him not sure about something. Now i don't trust anyone for building stuff because he is one of the leading mechanics in the area and even the only certified can-am spyder mechanic for miles and miles and is supposed to be one of the best and yet i still see him un sure about alot of things. lol so it makes me realize alot of these "professionals" are just normal guys who don't know everything lol. i like to double check and be sure. or i hate it when i correct him whens hes supposed to be the pro. lol
also where he works they dont take in old machines like trikes and stuff so hes not used to all the old stuff. we tore down the 110 and had things falling out that he didnt know what they were for and i had to find them in the manual. lol also i bought an old race carb the other day and the jetting comes out the side for easy changing and he had never seen that. also never saw the brass float it has.
it just lowers my confidence lol. thats the problem with working on everything is you cant remember it all, rather than just being a specific machine specialist.
you get what im saying, when he asks me to go ask the guys on 3ww rather than knowing its a confidence downer haha not that you guys arnt really knowledgeable because you are.

[NINJA]

If your father is still learning new things or says he hasn't seen something before or you see him pondering a problem, then I'd say he's a great mechanic. It's the guys that act jaded and never admit mistakes or claim to have seen and done everything that you should be leery of.

[MTS]

If your father is still learning new things or says he hasn't seen something before or you see him pondering a problem, then I'd say he's a great mechanic. It's the guys that act jaded and never admit mistakes or claim to have seen and done everything that you should be leery of.

That's very well put, There will always be something new, Or old you haven't seen before...Its much better to ponder on a problem You know Nothing of and Try to understand it, rather than Giver and make things Worse (most often then not)...Sounds like a guy worth learning from at any-rate. I'm Not quite sure why That particular company has a Hate on for synthetics. I did scan a few page's on Oils and Lubrication from some of my schooling on bikes..to give people a better understanding on it rather than a long winded post..cant seem to get them to load..to large of files??...not so wise when it comes to computers...will try to get them up...have Lots of other info too if anyone is interested.

[Mr_RPM]

alot of people, not just members like oil info. Oil threads get alot of views because non members on google looking for help will ponder along the site and take a good reading on oil. oil is always something we always question about even though we have all been using it for years. Everyone wants to find that miracle oil that they can poor in the will help promise a longer engine life. Its a hope everyone has that may never happen but we keep asking lol.
give us any links you might have on oil, more people than you might think will appreciate it.

and oh yeah my dad is a great mechanic, i just like to double check and even challenge him sometimes haha. helps us both learn. Its a Father n' Son thing lol

[Dirtcrasher]

I've got 4 HARD years on a 26 yo 350X engine thats never babied, never opened............

I run Walmart oil - 5 quarts for 11$ and I change it often. It does not tick or have clutch slippage. I read that and AGI, SLE or whatever rating system there is, the oils will all work relatively the same. So I roll with that.

But, I have 2 crate motors for spares and a 3rd in pieces :D

I'll have to talk to John about the diesel stuff so he can set me straight; I'm always open to options :beer

[MTS]

Here is The Few page's i have...Basic stuff...Might be a bit dated, But Info never hurts

[blue27]

What you have to watch is some syntheics will cause clutchs to slip, car do not have there clutches in motor oil, if you use a motorcycle synthectic they are designed for a motor oil wet clutch. I run Castrol 10w-40 and have no problems but my wife keeps telling me to use motorcyle specfic oil, blah blah blah. lol so far I have had no problems with Castrol and I like to agitate her.

[Cuztom Racing]

I run full syntheic Royal Purple Max cycle in all my race engines and i will run it in my 86 200x. It has a clutch additive. I've done a ton of research and called all the major oil companies and bottom line is Syntheics will work in all our ATV engines as long as it has a open clutch additive. If it doesnt they will slip..

[cr480r]

i read somewhere(sorry i forgot) that motorcycle oil was superior to automotive oil because automotive oil has stricter requirements it must meet for enviromental reasons... and that for the motorcycle oils they can put more zinc and phosphorus in it. I dont know if this is true but it sounds kinda legit to me.. Definately something worth looking into.. I know higher concentrates of zinc are used in engine break in oils and suppliments. Before reading that I always figured they just put the same oil in a bottle labeled "motorcycle" so they could charge more.. Lately I was actually thinking about using motorcycle oil in one of my trucks because nobody sells racing oil in my town, but i still gotta do some more research.. Supposedly regular oils contain detergents for longer oil life that can cause detonation in high compression engines.. I had it happen in one of my trucks when i tried some delo 15-40(diesel high detergent) i had given to me.. instant ping... put 10-40 back in.. ping was gone.. Then later i read that racing oils have special detergent additives for this very reason, but the oil doesnt last as long because of it. I wish I knew where to find this info again..

[Cuztom Racing]

Royal Purple Max cycle, hints the word "cycle", is a motorcycle oil made for wet clutch motorcylce/ATV motors only, it is not a automotive oil..

[Mr_RPM]

my dad ran the basic yamalube in an old subaru wagon. basically because the car was on its last leg and he gets the oil free alot of the time. It had no problems at all. I wouldn't do it to anything that matters but it worked.