Topic: Yes another Oil Question

[Quail "Owner of the comfortable k8"]

Is it ok to use the castrol GTX 20-50 like I would get at k-mart it does not say it is for motorcycles.   My k8 has 24,000 miles on it.

Terry

[douglascoolgrey]

I use motorcycle oil. I like my motorcycle.

I also like going to the motorcycle shop and talking with the people in the parts department. It may be their job to say so, but they also use motorcycle oil. No one at K-Mart has ever hooked me up with free stuff or offered good technical advice.

[Harry]

Check the oil FAQ. If the Castrol is a mineral oil, its ok. 20W-50 is also ok.

[heffay]

lets get to the bottom-a-this...
why mineral / 20w50

  i have my beliefs but i wanna hear yours too.

[Harry]

lets get to the bottom-a-this...
why mineral / 20w50

  i have my beliefs but i wanna hear yours too.

Well, from the FAQ I snipped:
"10-40w MINERAL oil is what Honda recommends. When these bikes were first sold, the API oil rating and formulation level was SD or SE. 20W-50 MINERAL oil can be used on older, worn motors. Don’t use synthetics. Synthetics have a reputation for a high detergent action. That is, if you have an old engine that has some sludge or deposits internally, the synthetic will sometimes remove it in chunks. There is some risk of plugging or restricting the oil pickup screen, which would starve the engine of oil. It also affects some old seals adversely causing them to leak (from shrinkage if I remember correctly) and often leads to clutch slippage (see Clutch FAQ for clutch slippage comments)."

Years ago I put high quality synthetic oil in the box and boy, did I quickly learn what clutch slippage feels like! Flushed gearbox with diesel which helped a lot, and changed to 10W40 mineral for winter, 20W50 for summer. Used a bottle of "stop-drip" additive too, worked a treat.

[Hop on a Honda]

The last one is 100%right.
The Honda has such small oil galleries for the oil, l that the pressure is absoutely parramount to get to the Over Head Cam.
Mineral oil actually lubricates rather than makes the the thing slippery and when the clutch friction plates ends up in the strainer then its all over rover. Red light warning. NO pressure.
It acts like blood, it actually carries the life through the engine too.
If you had to use oil in your engine I would protect it too with the best.
Castrol do make a dedicated 20w/50 for 4 strokes??.
Dave  in Australia.

[Uncle Ernie]

I use Honda brand 10-30. Automobile oil is now made for the closer tolerances of new car engines and is TOO slippery for motorcycles with wet clutches that share tranny and engine oil. Castrol 20-50 is good for a bike like a BMW, but not a Honda.

[kghost]

Come on now boys.... I've got a 72 750K2 and run Castrol 20W-50 in it with no problems
Buddy of mine runs it in a 71 bonnie and has had no problems.

Tried the Castrol act-evo 20W-50 and didn't like it, Its a semi synthetic.

On the other bike I have I run Aeroshell AD 120 which is detergent mineral oil for aircraft use. (its a new rebuild no sludge) and it loves it. Aeroshell was made for aircooled engines.

[fergie]

Honda 10-40 GN4. End of story. Fergie

[Dragman836]

I've used them all in my dragbike (74- 836,1050,&1080) and had no problems with any one or mix of any I really liked AMSOIL 0W-20. i KNOW that syn. oil is 5 molecuels longer than petroleum oil and it sticks to eng. parts when youtear a motor down you can feel it on your internal parts. therefore if you want cold start protection I sugest using it(them) Also I use 100% mobile 1 in my cruiser , no problems?

[Gordon]

I think the only concensus we're ever going to come to on this subject is this:

It is good to have oil in your engine.
It is bad to not have oil in your engine.
Synthetic oil is not advised for wet clutches.

I have heard plenty of folks extoll the virtues of the oil they use, but I have never heard anyone state that using a certain type of oil caused damage to their engine.  The only truly important point is that you keep the oil at the proper level, and change it (and the filter) when it's needed.  The rest is just personal preference, or whatever makes you feel warm and fuzzy inside when you buy it.

As for me, it's Castrol 10-30 in the Winter, 20-50 in the Summer.  I'm sure it would be fine with 10-30 all year long, but that's just what I like to do.

Gordon

[AndreRA3]

I agree with gordon on this, and will add the following:

I have used Redline synthetic for 500+ miles (I previously mistyped 1500 miles, but if you don't know what I'm talking about, ignore it).  Since then I flooded the crankcase with gas (forgot to close petcock) and put Royal Purple synthetic in.  Both were 20w50, none motorcycle specific.  Nothing evil has happened yet, but rest assured I will post something as soon as my engine implodes into a supernova.  I will also take donations for wheelchairs at that point.

BTW, people always say that synthetic causes wet clutches to slip.  How would that present itself?  I mean, would the bike rev up and not move even when the clutch handle is not pulled, or would it scratch into gear when I pull the lever?  That is, would it seem like the lever would pull itself at random, or would it seem that the lever won't pull at all? Answer me that and I'll waive the wheelchair donation bit.

André

[Quail "Owner of the comfortable k8"]

gordon

Is the Castrol 10-30 in the Winter, 20-50 in the Summer a special 4 cycle oil?  I can not find motorcycle oil!!!!

Terry

[kghost]

Synthetic oil causes loss of friction betwwen the friction plates and the steel discs. Manifests itself by slipping clutch. Just like it was worn out. Clutch disengages fine and lever works normal just slips under load.

Barnett Clutches are approved for synthetic oil. I have run them with both and have not had slippage.

[fergie]

Most modern bikes have wet clutches and they don't have any problem with slipage. all sorts of people are running synthetic in them .What gives?

[kghost]

Designed for them. We're dealing with 30+ year old stuff here. Like I said above the Barnett clutch plates work fine with synthetic. But, thier Kevlar and such.

[Einyodeler]

I`ve been using Shell Rotella T 15W40 for years and never a problem,WalMart has it in a 4 qt container for $7.99.

[smithrelo]

My bike has OIL?




Just kidding!
Linda

[x2qwk4ux]

YES!  IT'S OK!  IT'S CHEAP & WORKS FINE!  Been using it for YEARS!

[kansassteve]

Can someone tell what the 'API' rating means.

[Bob Wessner]

I believe it stands for American Petroleum Institute.

[Gordon]

The API code is not actually a rating.  It just shows that the oil meets current standards.  The code changes when new standards have been adopted.  They started at "SA", now we're up to "SL". 

Gordon

[dpen]

Bottom line is - oil and filters are the cheapest insurance policy you can have for your bike. Don't muck around with no-name or cheapies etc, it's not worth it in the long run.
Everyone has their own preference - mine is Pennzoil 20-50. I run this in my K7 as well as the FJ1200 & BSA Thunderbolt.
Use good quality oil, change regularly and your motor will love you. Just as importantly, when it comes time for a rebuild your motor will love you so much that it won't attack your wallet too badly.
It's a seventies superbike not modern plastic crap, therfore, no synthetic.

[Quail "Owner of the comfortable k8"]

So "The Answer Is..."  Yes you can use automobile motor oil in these 750 engines.  I was concerned I would do some type of damage not uing some 4cycle or motorcycle oil.

[kghost]

Hummm.....All the SOHC Hondas are 4Cycle.