CB750: What motor oil to use?

[BArTY]

Here's a loaded question I'm sure, but I am open to all answers and input.

What motor oil do you CB750 guys run? I've heard everything from partial sythetic to non-synthetic due to wet clutch systems in our engines. I've also read about Shell's Rotella T6 oil as being "the best" oil for our engines. Ton of people rave about it, but its labeled as a full synthetic, though many claim its not truly a synthetic. I'm hesitant to put it in my engine.

What do you guys run, success stories, failures?

Heres a link to the wiki article on Shell Rotella T6 motor oil
http://en.wikipedia.org/wiki/Shell_Rotella_T#Motorcycle_usage

[djelliott]

I've had good luck with Rotella 15/40.

[Jewbacca]

Castrol 20/50 MT motorcycle specific oil, no detergents, only about $0.25 more a quart, and the 20/50 being a bit on the heavy side keeps your 30+ year old engine nice and lubed.

[djelliott]

Bitch to start in the cold with 20/50 though.

[Flugtechnik]

Remember, Cpt. Square tire is in FL so his opinion is a bit skewed.




END OF LINE

[Jewbacca]

I'll take that as a compliment, yes, down here in FL, 20/50 doesn't affect cold starts since it's 70+ for 11 months. In colder weather, I'd go with 15/40, and keep it in the garage. Oh, and btw, it's not square tires anymore, chicken strips are only about 1" wide now, found a couple of nice curvy roads a few months back.

[BArTY]

I've used Castrol 10-40 in the passed and had an engine seize up on me. Rebuilt engine needs to be properly cared for from the start so I'm very picky when it comes to what oil I'm using. Heard great things about Rotella and would like to try it but I'm hesitant with it being called a "full synthetic".

P.S. I'm in Southern Cali so 20-50 is probably best for me too. Its friggin HOT!

[djelliott]

I should clarify, I use the Rotella T Triple. Not the synthetic..

[crazypj]

Rotella 'synthetic' also has a 10w/40
I add about 2oz of ZDDP as levels have been dropping for years and have been removed from most automotive oils
'Our' engines were designed when ZDDP levels were around 1800ppm, today, levels are around 1200ppm which is the lower limit.
Just about any diesel oil still has ZDDP in it.
Main reason to remove it is catalytic converters, it 'poisons' them so automakers want it removed.
They have to warranty emissions for up to 5 yrs/100,00 miles 'cat' could be changed at no cost to owner under warranty (could get real expensive, real quick)
 I'm running Rotella 5w/40 in all my bikes (with added ZDDP)

[Wolfie]

I have used Castrol 10-40 for over 40 years in all my bikes.
(And I am a Amsoil dealer, and still use Castrol 10-40)