What engine oil for 1982 XJ750 Seca

I'm looking at the Manual for a XJ750 Maxim online and it recommends either 20w/40 if temps above 5°C or 10w/30 if temps below 15°C

What should I use? Or should I just go with 10W/40? (Looking at other posts)

 

Howdy!

I have an XJ750 Maxim, and I run 10W/40 with no issues so far. I run conventional oil in mine as it prefers running on dinosaur bones, but I think there are some folks on the forum running synthetic.

 

The short answer is: just use Shell Rotella T4 15W-40 and sleep well at night.

Of course there are other options and opinions. The main discussion of the topic is here: https://www.xjbikes.com/forums/threads/choosing-the-correct-oil-for-a-wet-clutch-motorcycle.43702/

 

Would that be better than 20W/40? I don't plan on riding below 0°C

 

I don't think the cold viscosity rating of 15 vs 20 will really make a difference. They are both "warm" rated at 40 anyway, so in theory, once warm, 15W-40 would be the same as 20W-40.

Most of the discussions around here about what oil to run are mostly about base stock and additive packages.

The consensus is that Rotella T4 15W-40 is the best option, for several reasons:
1. It is old-school mineral base stock (not synthetic). Some people have reported drive clutch and starter clutch slippage with synthetics.
1. It is JASO rated (plays nice with wet clutches). Does not have the friction modifiers that wet clutches don't like
2. It's widely available (WalMart usually has the best prices and will deliver for free, at least for me, your mileage may vary)
3. It is inexpensive

Given the millions of miles ridden with Rotella T4 15W-40 and no known problems that can be traced to the oil, it is by far the safest bet.

 

http://xjbikes.com/forums/index.php...orrect-oil-for-a-wet-clutch-motorcycle.43702/