Motorcycle Safety & Driveability: Oil levels... manuals for Suzuki GN250, oil levels, auto oil

Question
I just acquired a 1992 Suzuki GN250 motorcycle... I need to know:

a) Where's the dipstick?  
b) How much oil and what sort of oil does she take?  (ie. What oil is recommended...? or will any 10w40 oil do?)
c) How can I tell how much oil to put in without a diptstick?
d) Any idea where I might be able to lay hands on a copy of the workshop manual for this bike?

Thanks mate; hope you can help...


Answer
There's no dipstick on the GN250, however, there is an oil sight window on the right side of the crankcase to measure oil.

10w40 is fine. I recommend you use motorcycle-specific oil and not automotive oil, because the engine and transmission share a crankcase (the transmission gears shred the oil polymers so it breaks down very quickly with regular auto oil). But I've used regular auto oil in older bikes and it seems to work okay.

You can buy a shop manual for it online at places like Jcwhitney.com, clymer.com, or themotorbookstore.com.

Good luck and have fun.

Pat