Topic: Best oil for 1974 Honda CB750

[jembers]

I know this subject is probably beaten to death. In a search there are so many opinions out there so I have no idea what I should be buying. I'm also new at this.

I'll be buying from fortnine and was wondering if you guys suggest anything in particular for my .74 Honda CB750?

https://fortnine.ca/en/motorcycle-oils-chemicals?cat=1082

Thanks in advance.

[Stev-o]

Best oil?!  Click here....


http://letmegooglethat.com/?q=Best+oil+for+SOHC+CB750

[Honda3]

I know this subject is probably beaten to death. In a search there are so many opinions out there so I have no idea what I should be buying. I'm also new at this.

I'll be buying from fortnine and was wondering if you guys suggest anything in particular for my .74 Honda CB750?

https://fortnine.ca/en/motorcycle-oils-chemicals?cat=1082

Thanks in advance.

I have 5 bikes. I have oil experience.

No snark here. I noticed one reply and reminds me that I cant stand when ppl are rude to ppl who have legitimate questions. Its stupid.

Happy to help. Valvoline 4 stroke 10W40:  https://shop.advanceautoparts.com/p/valvoline-4-stroke-motorcycle-10w-40-conventional-motor-oil-1-quart-vv740/8080023-P

[RAFster122s]

Oil threads are classic flame fest or high dissention topics on automotive and motorcycle forums.
Spectro makes a good oil for our bikes using mineral oil.  20w50 weight for above 40F operation and it has the necessary Japanese MA2 clutch compatibility.
There are other good brands, some are better than others. Old SOHC motors require a certain level of ZDDP in the oil as well, the Spectro oils have enough to provide the needed lubrication for the camshaft and rockers.

If you have to buy from Fortnine, the Bel-Ray EXL mineral 4T would be my first choice followed by Motul 3000 mineral 4T oil.

My $0.02

[DaveBarbier]

I also use Spectro, but that’s not on your list. When deciding on oil the tie breaker for me is the zinc levels. Higher the zinc the better. 3% is good. Break in oils usually have like 3-5%. You can find the zinc levels in the safety data sheet on the manufacturers website.

The Valvoline Honda3 links to has less than 1%. He really has no idea what he’s talking about so ignore him.

The reason zinc is important:
http://forums.sohc4.net/index.php?topic=119643.0

[PeWe]

There are several fresh threads about this and is easy to find if searching.
Do not forget 20W-50 bike oil (wet clutch) for a CB750

[andy750]

I bave used Shell Rotella 15w-40 - from wikipedia

"Though marketed as an engine oil for diesel trucks, Rotella oil has found popularity with motorcyclists as well. The lack of "friction modifiers" in Rotella means they do not interfere with wet clutch operations. This is called a "shared sump" design, which is unlike automobiles which maintain separate oil reservoirs - one for the engine and one for the transmission. Used oil analysis (UOA) reports on BobIsTheOilGuy.com have shown wear metals levels comparable to oils marketed as motorcycle-specific."

I have recently started using Motul Aceite 4T 5100 10W40 4T 4L (semi-synthetic) in my 1974 CB750K4.(836cc). Attached are the safety data sheet and technical data sheet.

For years I ran regular car oil with no apparent ill effects until I opened up the engine and oil was baked into the lower cases. Lot of top end parts had to be replaced though it was at 60,000 miles. Depends really on your budget and long term investment in your bike. As DaveBarbier points out zinc is good for our engines though I searched for zinc content in Motul could not find it.

good luck
Andy

[ekpent]

I know this subject is probably beaten to death. In a search there are so many opinions out there so I have no idea what I should be buying. I'm also new at this.

I'll be buying from fortnine and was wondering if you guys suggest anything in particular for my .74 Honda CB750?

https://fortnine.ca/en/motorcycle-oils-chemicals?cat=1082

Thanks in advance.

I have 5 bikes. I have oil experience.

No snark here. I noticed one reply and reminds me that I cant stand when ppl are rude to ppl who have legitimate questions. Its stupid.

Happy to help. Valvoline 4 stroke 10W40:  https://shop.advanceautoparts.com/p/valvoline-4-stroke-motorcycle-10w-40-conventional-motor-oil-1-quart-vv740/8080023-P

  Steve showing a whole list of previous oil threads here on the forum sounds helpful to me and not "snarky". Think he deserves a Thank-you !

[jlh3rd]

I'm a manual guy unless specifically proven otherwise. So here's this from a manual. Also, oils labeled " energy conserving " are not good for our wet clutches, stay away from them. They've reduced zinc ,as stated, so use an oil that has more, i use the rotella for that reason. Synthetic oils are best, my opinion, except my 550f began seeping from the head gasket ,so i switched back to conventional...it stopped seeping. I don't ride my bike, so i don't need the better synthetic protection . Looks like 10w-40 , 20w-50 is recommended. But, define " extremely high temperatures "...

[frenchy51]

Spectro 20-50 is what I use (to replace Castrol-that I used to use). Seems to run better and shift smoother with the Spectro. It's all I'll use in my '76CB750F. It's known as a Harley Oil but works wonders in my Honda.

[Tracksnblades1]

I know this subject is probably beaten to death. In a search there are so many opinions out there so I have no idea what I should be buying. I'm also new at this.

I'll be buying from fortnine and was wondering if you guys suggest anything in particular for my .74 Honda CB750?

https://fortnine.ca/en/motorcycle-oils-chemicals?cat=1082

Thanks in advance.

Jmember,

https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/

This is a lengthy read. Read at least to the last update date (9/2/19).... You will find it's updated regularly.

A Canadian's ME approach to oil testing to failure. Warning this is like the shower room, yours may not measure up.

Rotella oil is a great oil for diesels...I've used it for years.. It's yield strength is around 71,000-72,000psig old/new.  Plenty for large area diesel rod and main inserts....

Check out the new natural gas developed oils yield strengths besting 120,000psig. Perhaps even designed for the demand of today's small area rods and mains.

Honda's owner manual for their new air cooled cb1100 specs 10w-30.  To add more confusion, the new cb1100 crankshaft rod and main bearing clearances are similar to old cb750...
But then most all of the 10w-30 oils tested very high....

Choose well....

[jamesw]

I buy the Bel Ray 4L 20w50 EXL mineral oil from Fortnine whenever I need oil.

[johans]

Honda 3   +1 on your response  =)

[Honda3]

Honda 3   +1 on your response  =)

Thanks. Its SO much nicer to be nice than not.

[Duke McDukiedook]

For these bikes Spectro oil is your friend and Bob is your uncle.
Anything with zinc in the oil is what you want to use otherwise.

[PeWe]

New engines in general  have much tighter tolerances and therefore thinner oils. A thick oil will have issues to enter those thin gaps were oil should be, especially at cold start.

CB750 is old tech. If you have a pressure gauge mounted you will see if oil is too thin when running very hot, pressure will not keep up. Bearings might scratch metal to metal.
Crank bearings, rod- wrist pins and cam shaft/ rockers get scuff marks.

Not only a very hard gearbox with problems to find neutral when really warm.

Viscosity must keep up the pressure when really hot. Synth is therefore often used.