1-w40 oil is too light for a CB750, if that's what you are asking about.
Use never less than 15w40 diesel-rated oils, 20w50 is much better. Avoid detergent oils in the 750.
Sentence 2 & 3 are conflicting. Use never less than “15w40 diesel-rated oils, …. Avoid detergent oils……🤔
Diesel oils are some of the highest detergent oils made, excepting perhaps Mobil 1…..
Detergent oils are known to neutralize acids and prevent oxidation and corrosions…
Even Shell’ AeroShell” non detergent 65 - 120 oil designed for piston engines (not non detergent hydraulic oil) is only recommended for break in for new or newly rebuilt. It’s been along time since the no oil filter engine days….
Even Honda originally included dg & dm (detergent diesel oils of the day) recommendations in their service manuals.
What non detergent oils of today are currently rated for flat tappet type camshafts or diesels ?
🤔
Shell's Rotella diesel is one good, low-detergent oil, and there are others. If you use high-detergent oils in diesel engines it can cause them to not be able to shut off, even when the Emergency Stop air dam has been dropped, if the engine is running hard and fast. The foaming oil becomes a fuel for the engine. We learned about that with 2400 HP frac engines in the 1980s when I was then directed to create halon-injection systems to guarantee E-stops when someone had installed the wrong oil by accident. It happened more than once! I can't even begin to describe how dangerous the situation was that this scenario created, but as it ended, I had 2 more 'backup' systems behond those to ensure shutdowns. That worked, and still works today. 
I don't understand why you would install a halon system to chop a diesel where a gate valve does a better job and you can buy them ready made for most intakes. Or, just slap a piece of plywood over the intake opening and it dies toute suite.
Not to mention, firing off a halon system requires hours of paperwork afterwards. We had halon fire suppression systems on all our choppers and fast movers and when one fired off accidentally (maintenance, not inhibited, tech not paying attention to which button/lever, etc) we would all let out a collective groan because we knew there was going to be hours and hours of environmental impact paperwork, investigations, interviews, etc.
I've never heard of a runaway diesel because it had a high detergent oil in the crankcase and I've worked on diesels for a good 35+ years. Sure, crankcase oil will burn in a diesel, but there's no way for it to get into the combustion chamber unless there a mechanical fault somewhere.
Not trying to bust your B's, but none of that makes any sense to me......
👍 Exactly….Read my mind….
Only engine I’ve seen run on its blow-by had over 600,000 miles. A VW rabbit engine, a whole 52hp NA diesel…
It would only “idle” on its blow-by and not shut off. The owner rerouted the hose to the atmosphere, stayed out of California, and it shut off without holding something over the snorkel hole.. A far cry from a 2,400hp engine that would probably consume the Rabbit’s WFO fuel delivery at an idle…
The halon systems I’ve seen on heavy equipment were on coal (ignitable dust) equipment, and they utilized high rpm automatically triggered intake air shutoff valves…similar setup to what the larger modern diesel trenchers use to keep from runaway rpm if it cut through buried gas or fuel lines, excepting no halon systems….
Surely there must have been a direct path to the intake. A bad turbo or supercharger oil seal was common back in the day…
Old 2cycle Detroit’s had their intake air shut down valve incorporated in the GMC blower housing. No compromising of the air filter system that way….
I still don’t know of any “low detergent” Rotella. Shell is constantly bragging about their “triple protection additives” ability to keep class8 engines like new clean….🤔
