Spark plug socket size and what spark plugs to get?

[Bminder]

So I my 92 FJ1200 purchase home. It hasn't been running for 3 years, the tank was drained but not the carbs. I want to pull the plugs, but they must be a metric size. 13/16 is too big, and 5/8 is too small. The parts store told me that's all they carry for plug sockets.
What size are the plugs?
Also, what brand of plugs do these motors like best?
Thanks

[racerrad8]

18mm

Randy - RPM

[yamaha fj rider]

Any quality spark plug you should be ok. I think my 93 came with NGK.

Kurt 

[Bminder]

Thanks guys.
So these motors aren't too picky about what plugs you use?
Some engines are kind of finicky about their plugs.

[Pat Conlon]

It depends on the oil you're using...... 

[Bminder]

Haha, ok. What oil do you recommend?

[Harvy]

resistor - NGK DPR8EA-9.    standard NGK DP8EA-9.   Iridium NGK DPR8EIX-9

Al .9mm gap


Harvy

[movenon]

It depends on the oil you're using...... 

Pat, your feeling feisty tonight     
George

[ribbert]

It depends on the oil you're using......  

....and whether you're running double clutch springs, in which case you left hand would have developed enough strength not to need one.

[Steve_in_Florida]

Kind of along the lines of this thread:

I want to perform a compression test on the bike.

What size adapter is required to fit the spark plug hole?

The gauge I have has an 18mm and 14mm adapter, but they're too big.

[movenon]

Kind of along the lines of this thread:

I want to perform a compression test on the bike.

What size adapter is required to fit the spark plug hole?

The gauge I have has an 18mm and 14mm adapter, but they're too big.

Spark plug thread size 12mm X 1.25. Take a look at this adapter  http://www.toolsource.com/adapter-clt2-compression-tester-14mm-12mm-p-100140.html
Spark plug TQ 12.5 ft lbs
George

[Bminder]

The Clymer books says to use 20/40 weight oil.
Will 10/40 work?
What are most running?
And is there an advantage to full synthetic? I switched from synthetic blend to Mobile 1 in my Dodge Ram 5.9 gas and it started using oil and I saw no improvement in mileage, so I switched back to synth blend and it stopped using oil.

[Pat Conlon]

Serves me right for opening the door...

10w-40 is fine. Any oil is fine as long as it doesn't have friction modifiers in it.
Full synthetic is fine, synthetic blend is fine, Dino oil is fine.

Oil is a debated topic on this forum. Everyone has their favorites. Do a search for more discussion.

Cheers.

[Bminder]

Over the years I've read tons of discussions and reports on motor oils.   Seems like the conclusion is that all oils are so good these days compared to 40 years ago that anything you use will exceed the manufacturer's requirements.

So I go to my backup parts store Autozone because my main parts store Advance Auto doesn't carry 18mm sparkplug sockets.
The guy at Autozone says, "I've never heard of 18mm sparkplug sockets, I don't think there is such a thing."
And we walk over to the socket section and right there is an 18mm sparkplug socket.

[FJSpringy]

Over the years I've read tons of discussions and reports on motor oils.   Seems like the conclusion is that all oils are so good these days compared to 40 years ago that anything you use will exceed the manufacturer's requirements.

So I go to my backup parts store Autozone because my main parts store Advance Auto doesn't carry 18mm sparkplug sockets.
The guy at Autozone says, "I've never heard of 18mm sparkplug sockets, I don't think there is such a thing."
And we walk over to the socket section and right there is an 18mm sparkplug socket.

If its anything like the auto stores near me it's instant dismissal once the employee exhibits any product knowledge