General motor information for newbies

Hello everyone! I’m new to bikes completely though I am mechanically inclined. I bought my first bike being a 1982 KZ 750. The guy who sold it to me said it was a Twin. Now I’m noticing as I learn that it is not. The vin is hard to read but I am in the process of trying to figure it out. On this bike the motor reads 750B. Which I presume is 4 cylinder. But this head only has 2 spark plugs and 2 exhaust ports. Please school me!

Welcome to KZRider 
2 plugs , 2 carbs  , 2 exhausts     equals a twin cylinder bike
I fixed your pictures for you to be full size 
Next time complete the install by  clicking the install all tab 
Dave

The pictures are a Twin as is the engine number. It's possibly an 80 G1 Ltd.  see replies below >> KZ750-M1 CSR.
www.cyclechaos.com/wiki/Kawasaki_KZ750G  
www.cyclechaos.com/wiki/Kawasaki#KZ  

Here's a 4-cylinder. It's a KZ650-CSR but the 750H Ltd is virtually identical in appearance.
The exhaust pipes on every other KZ In-line 4 are going to look pretty much the same

Buy/download a factory service manual.

It's likely a 1981 KZ750 M - right year, twin-cylinder, spoked wheels.

It may have had it's engine swapped at some stage. The engine has KZ750B1 stamped, which would sensibly match a 1976 KZ750 B1 . But I'm not an expert on engine numbers/codes and how they work.

Whatever the case - you have a KZ750 twin, not a four. Kawasaki were quite annoying in that regard - they had a KZ750 inline 4 (KZ750H, KZ750E, KZ750F) and also had a Kz750 twin (KZ750B, KZ750G, KZ750M). It's very confusing - even some of the CycleChaos links are wrong listing i4s as twins and vice-versa.

Whenever you are buying parts, check that the letter matches for a twin - most KZ750E parts will not fit on a KZ750B for example.

When I got my KZ750H2 (inline 4) I think the previous owner got a rear sprocket for a twin, because they put a 38 tooth sprocket (stock on a twin) on the rear instead of the correct 32 tooth (stock on a inline 4). The gearing was all messed up, but gee it was fast off the line.

I think you're right about it being a KZ750-M1 CSR.  It's hard to see but it appears to be stamped KZ750BExxxxxx.  All 750 Twins appear to use the same engine numbering.  The engine is probably original to the motorcycle.  I forgot about the 750-CSR, doh. 

There was also the 750K, twin cylinder, belt drive, LTD. As Martin said, so far as I have been able to discover, all of the 750 twin models used the same engine, so they are all stamped with 750BE.
You can download e document I linked to below, and look for your frame number to verify the model.

www.kzrider.com/filebase/download/64-gen...78-kz-by-the-numbers

The only way to know for certain which model you have is by looking at the frame number (vin) stamped on the head stock. There should also be a decal beside the stamped number with the frame number, date and country of manufacture clearly printed on it. Since your bike has been repainted, that decal may not be visible.

You might find the link helpful   kz750twins.com/?cat=23  

You can find manuals to download, info on frame and engine numbers, ect.