Topic: Oil Recommendations

[Vintageguy]

I know this is a rabbit hole, but what do y'all think is best oil for a 1978 CB750F with 9,000 miles? I live in Florida and obviously it gets real hot here. I do get some false neutrals at times. Currently running Valvolene synthetic 10-40 as per factory handbook. I know some other references state 10-50, others 20-50. Any responses are appreciated. Thanks.

[bryanj]

10w40, 15w40 but mineral not synthetic, synthetic isn't worth the extra cost as you cant leave it in any longer

[American Locomotive]

There are a billion different opinions. Some people run 10w40, some 15w40, others 20w50. I used to run Rotella 15w40, but I switched to 20w50 this last oil change and the shifting seems a little better. I'll probably go back to Rotella next oil change to see if the shifting is actually noticeably different or if its just in my mind.

Basically anything between 10w40 and 20w50 will be fine. Look for the "JASO MA" rating on the back of the container, which means it suitable for wet clutches. If it doesn't have the JASO MA rating, make sure it doesn't say "Energy Conserving" otherwise your clutch will slip.

[PeWe]

Search with Google:
Sohc forums + cb750 + motor oil
Motorcycle oil semi synth 20W-50 is my tips.

[jlh3rd]

manual says 10w-40...or 20w-50. If oil says energy conserving,as stated previously, don't use it. Synthetic oil offers a higher degree of protection against viscosity breakdown, excellent for aircooled engines. It did cause my 550 to seep oil from the head gasket...so I went back to conventional...others seem to have good luck.....
     I use the rotella for diesel engines because zinc has been reduced in automobile oil..my understanding...( google it)....I'm not sure if there is a synthetic diesel...
   

[beemerbum]

I know this is a rabbit hole, but what do y'all think is best oil for a 1978 CB750F with 9,000 miles? I live in Florida and obviously it gets real hot here. I do get some false neutrals at times. Currently running Valvolene synthetic 10-40 as per factory handbook. I know some other references state 10-50, others 20-50. Any responses are appreciated. Thanks.

For what its worth, when I switched from 20-50 Maxima to 20-50 Spectro in my K7, the shifting improved noticeably.

[Vintageguy]

hecked and bottle says JASO MA, and not engergy conserving, so I guess I got that part right (by accident). Also says specifically for wet clutches. Guess I'll go with what I put in there this time, and try 20-50 just for grins next time and see what (if anything) happens. Thanks, all.

[newday777]

hecked and bottle says JASO MA, and not engergy conserving, so I guess I got that part right (by accident). Also says specifically for wet clutches. Guess I'll go with what I put in there this time, and try 20-50 just for grins next time and see what (if anything) happens. Thanks, all.

That'll work. 20w-50 is good for high heat. But hard starting in the winter temps.

[Vintageguy]

Thankfully no real winter temps in Florida.

[bryanj]

not just hard starting it takes longer to get to the cam

[grcamna2]

I regularly use Rotella T4 15/40 and the bike starts,runs and shifts very well,I've been running it for years and a gallon is less than $15.My clutch basket 'fingers' are 'notched' from hard powershifts on my bike and I need to remove my clutch basket and file those notches smooth:that really causes me hard shifting.