Oil Spec 81 CB750C

[ArjaiC]

Hi everyone, great site here!! I am thinking of using Amsoil Metric 10w40 in my 81. The website says it is compatible with wet clutches with the GL-1 specs. Not Gl-4 or 5. I checked my new Clymer and the owner's manual. No where do I find anything referring to GL-1. This is the oil: http://www.amsoil.com/shop/by-product/motor-oil/motorcycle/10w-40-synthetic-metric-motorcycle-oil/?code=MCFQT-EA I am pretty confident it will be OK. Just thought I would ask you all since there are many more of you familiar with my bike. This is my first bike in 20 years, love it by the way, and I don't know if this will be fine or not. Thanks! [hidden email]

[TOOLS1]

Oil is the most often debated subject on motorcycle forums. Everyone seems to have their favorite brand that they are loyal to death over. I recently had a discussion about oil with my friend that owns/runs an independent repair shop that does a lot of work on older Japanese motorcycles. Amsoil did come up in the conversation. He said that they had seen motorcycles come in with engine damage that had been using Amsoil. He would not recommend it. His preference was Castrol GTX. He has started using it years ago in his drag bike after several engines with crankshaft damage, and not one after switching to Castrol GTX. Myself, I use Havoline oil. When I worked as a mechanic for a Ford dealership years ago, I took apart many engines. Most had some dirt/sludge in them, some looked like they had a cake with with fudge icing baked in them, and some were spotless. I would inquire about the oil used. The cleanest engines with the most miles almost always used Havoline. I have used it in all my vehicles since then. However Havoline oil is getting hard to find now. I might be switching to Castrol GTX unless I can find some place still carrying it near me.
Another popular oil for motorcycles is Shell Rotella. This oil is easy to find, and very affordable.
Whatever you decide to use, just be sure to change the oil and filter regularly. Evey 2K miles, or every season if you do not ride that much.
TOOLS

[ArjaiC]

Funny, I have been reading posts, for a few days, and I could have predicted your love of Havoline oil.

Also, I find it funny that your friend sees one engine and condemns an entire company.

I have no real love for oil, aside from the one I sell at work, Pennzoil. However, they do not, to my knowledge, sell a synthetic wet sump MC oil.

So, after spending a, short, time researching synthetics, I came across a number of names I had not encountered before and others, that I have.

Of those, AmsOil is, by far, the best of that lot. What threw me for the loop is that they list a Gear Oil number. One I could not find in any of my resources, pertaining to this bike. So, why they did that I am unsure ( does anybody run gear oil in their Honda's?).

What I am asking then is, aside from Tools Buddy, does anybody fear this oil is bad for the bike, in question AND has anybody used AmsOil in their Vintage Honda and had issues?

Not sure that will narrow it down but, let's not turn this into an oil argument. I'd rather stick a fork in my eye!

[TOOLS1]

It was more then "one" engine. This shop probably works on a thousand bikes a year. You seem to be sold on the Amsoil so go on and use it. I did put it in one bike for one of my customers that insisted on using it. It has been working fine, but the bike is hardly ever ridden. It did however start leaking oil after putting the Amsoil in it. As for gear oil, the transmission shares the oil with the engine and clutch. I doubt either one of them would work well with the thick gear oil.
TOOLS

[ArjaiC]

That, is the thing with synthetics. If you have a leak, possible gummed up with carbon, synthetics will immediately show you the spot! So, if one's gaskets are in good shape, it will not cause leaking.

I am not necessarily "Sold" on AmsOil. But rather don't want Royal Purple (junk, BTW) and the other few names I hadn't heard of.

I will do some more research. I need to know more about this, before my next change, probably in June.

If anyone else has a synthetic suggestion, please feel free to mention it hear.

Thanks, oh, and Tools, sorry I misunderstood. But I have a feeling the problems with those AmsOil bikes was not directly caused by the oil.

Oh, and another thing. Rotella, putting a diesel oil in there does not cause smoking? Plus, that stuff is god awful smelling!

Thanks for putting up with me, a "New" newbie, or, a Second Hand Newbie...My last bike was in the late '80's, early '90's. I had a 750 NightHawk, then joined the Army, Came back and had forgotten how much I loved Riding! I feel like I have re-discovered an old flame!

Unfortunately, this time around I don't have a garage to work in. But, I shall adapt.

[shinyribs]

Nah, Rotella won't make an engine smoke. It's referred to as diesel oil, but diesel's are just engine's, too! Rotella is designed for tractors, earth moving equipment, semis, etc. Those guys are hard on engines and they pretty much sit under load nonstop.  Cheap, tough oil that is designed to work with wet clutches - almost all tractors and earth moving equipment run wet clutches. Rotella supposedly ( I don't have a way to verify this) has the highest zinc content of any off the shelf oil, so that makes it's good for older engines with valvetrains such as ours ( sliding surfaces vs modern roller surfaces).

Not bike related, but when I started Running Rotella in my drag car I stopped losing cams/lifters. And I was buying offroad only, racing oil that was supposed to be chocked full of zing up until then ( Just happened to be Pennzoil, btw... lol). I fully trust Rotella in any engine. I think it was just able to handle the heat better--which is also good for our old air cooled/ oil cooled engines. It's just a bonus that it's so inexpensive. Supply and demand, though. Sooo many semis and farm equipment and other stuff running around using that stuff ( some of those trucks hold 10+ gallons)...it helps keep the price down, I think.

The reason it gets called diesel oil is because it's help control soot in the oil, which gas fired engines don't really have to worry about.

[ArjaiC]

OK, which Rotella? The T4 conventional, T5 Synthetic Blend or the T6 Full Synthetic?

I am a fan of it, But have only sold it for diesel engined trucks, and it smells awful draining that oil out!

If T6 is useable in my '81, I will use that!
 

[ArjaiC]

Also, can I get away with using the 5w40? Everything I read says 10w40. I know I won't be riding in the winter but, cold morning starts will still be good w/ the 5W40, I imagine.

I am actually amazed that I could use this in my Motorcycle. But it make complete sense, the more I think about it! Even better bonus? I have EcoBoxes of this stuff at work!! 3.7quarts won't even be a drop in the bucket!

[ArjaiC]

Thanks guys! I think my mind is made up! Can't believe the answer has been right under my nose, the whole time!! LOL! And at my price!!

Next stop, filter purchase.
http://www.motorcycle-superstore.com/6553/i/hiflofiltro-oil-filter
http://www.motorcycle-superstore.com/6547/i/k-n-performance-oil-filterhttp://www.motorcycle-superstore.com/18609/i/vesrah-racing-oil-filter

[shinyribs]

Personally, I use the conventional 15/40. I use it in everything I own. Bikes, trucks, Jeeps, tractors...only one type of oil to keep around.