Topic: Break-In Oil?

[jrich44]

For a newly rebuilt CB750 engine would you recommend a special break-in oil? I have a gallon of cheap conventional 10W-40 because I assumed I would dump it relatively soon. Would I be better off with a better quality oil like Rotella from the beginning?

[calj737]

You will get a HUGE array of opinions on this topic. I would never use cheap oil under any circumstances in any engine, especially if I just rebuilt the darn thing. Quality oils always.

Special break-in oil: that's up to you. I'd suggest you decide between the following math problem: 4 quarts of oil costs about $20, plus a filter, another $10. Or opening up a freshly rebuilt engine and replacing a bearing, a ring, or chain due to insufficient and inferior oiling. Cost: priceless.

You decide.

There is simply no definitive answer and anyone that expresses their experience, is telling you their anecdotal experience. Some do, some don't. It's a decision you need to make. Me, spend the money and don't cost yourself 10x more than you save.

Hope that helps in some way-

[70CB750]

You could go with Mobil Delvac - gallon for 13 bucks or so in Walmart - and that's definitely a good oil.
Or Valvoline 20W50 for motorcycles in the same place will not set you back much more.

What Cal says, are you gonna take your chances?

[ekpent]

Conventional oil for break in so the rings can seat well and also a proper run in without a lot of idling or prolonged running at one low rpm range. By fluctuating the rpm's you help the rings to seat better.

[flybox1]

I'd suggest you decide between the following math problem: 4 quarts of oil costs about $20, plus a filter, another $10. Or opening up a freshly rebuilt engine and replacing a bearing, a ring, or chain due to insufficient and inferior oiling. Cost: priceless.

You decide.

Amen brother! 
You'll probably never hear "this highliy recommended oil killed my fresh rebuild"
My first oil change was at 50 miles, and ran me $50.  I used Valvoline VR1 20w50 conventional.
Thats a $1 a mile!  I made sure I got every rpm out of that $1   
Its an investment in the longevity of your engine.

[Jerry Rxman Griffin aka MuthaF'er]

How about conventional motorcycle specific oil (for the clutch's sake). Honda GN4 10w-40 comes to mind. Conventional to help the rings seat. Synthetic thereafter.

[Don R]

 There are break in additives you can add to your oil, Lucas makes one. It contains more zinc, moly and whatever to coat your wear items. 
 I'd use the Honda or Valvoline 20w50 motorcycle oil. Save the cheap stuff for a throwaway engine.

[lrutt]

Conventional oil for break in so the rings can seat well and also a proper run in without a lot of idling or prolonged running at one low rpm range. By fluctuating the rpm's you help the rings to seat better.

+1000. Do NOT use synthetics. Use a motorcycle grade oil that can live in that tranny. I think I'd wait a few thousand miles before switching over to syn's myself. Has worked well for me in the past. Some of my bikes I never switched over.

[lucky]

When the CB750's came from the factory they got non detergent oil for the first 500 miles, then they got regular oil after that.

[jrich44]

Thanks for everyone's input. On a side note, has anyone had experience with Amsoil motorcycle oil. I have an Amsoil dealer account and noticed they have motorcycle specific oil (synthetic). I have had good luck with their oils in my other vehicles so far and was thinking about trying it in the cb750 after the engine is broken in with conventional oil.

[calj737]

I use AmSoil extensively. If all my cars, trucks, bikes, boats, and equipment. Nothing better that I have ever found or used.

It is my opinion that their motorcycle oil is perfectly good for these engines. I've used it in all my wet clutch bikes with zero issues.

[jrich44]

I ordered some Amsoil 10w-40 motorcycle oil last night. I'll try that after I run Rotella conventional oil for a while. Thanks for the input.