Ok, from experience so far -

Airbox rubber
Inlet stub
Carb
Throttle cable
2-stroke pump and tank
19inch rear wheel
CDI slightly tamer
Stator coil for lighting circuit has 2 coils opposed to one
Ignition key under seat
Steel tank
Exhaust is different

The pistons DO interchange, SR and R piston are different, but they DO interchange
The head is the same
Not sure on porting, people claim its different but I'm yet to see them side by side
There is a thermometer on the SR head that goes to the CDI, not sure of its purpose? (if anyone can answer)


If anyone has any more to add or in better detail, slap it in after

Some other differences that I can think of are:

Gear ratios (see separate post)
Swinging arm
Exhaust is bolted to front of cylinder rather than by using springs
Front brake master cylinder (probably) as it has a brake light switch incorporated.
There is extra framework under rear guard to fit blinkers and rear extender to.
Thermostsat in cylinder head

No idea about the thermometer on head going to CDI - my 1989 Aussie F model (SR) doesn't have that.

Cheers

Do you know what the different gear ratios are?

Thankfully my SR came with a bolt to spring adaptor :D

I've just posted up the gear ratio differences:http://www.dirtrider.net/forums3/sh...ad.php?t=181527

Looking up the part #'s at kawasaki-motors.com/ for the SR, and buykawasaki.com for the R, I saw that the head, piston, rings, cylinder, base gasket, and cases were different.
Here's the part #'s:

Part________SR model_____R model_____prices for R parts
head_______11001-1301___11001-1291__$186
piston______13001-1290___13001-1295__$ 69
rings_______13008-1110___13008-1116__$ 33
cylinder_____11005-1585___11005-1569__$427
base gasket_11009-1817___11009-1994__$ 6
cases______14001-5264___14001-5262__$433

Looking up the SR parts costs at www.bikebandit.com I saw that the head, cylinder, piston/rings, and cases were not available. So they'd have to be gotten from the UK (contact corby.kawasaki@btinternet.com) although I have successfully used regular R model piston/rings, head gasket, and base gasket.

Piston - The only difference in the piston is the ports on it, the SR ports are 5 small holes and the R piston has one big hole.

Head - I have the head from the R and SR model, the only difference is the SR has a temperature sender in it which goes into the CDI for some reason? (perhaps a thermistor to alter the timing? blanked since I bought the CDI Jaguar above makes :D! CHEERS AGAIN FOR THAT! i've put switches on the rad guards now to change "maps")

Cylinder - only thing I can think is the porting might be different, power valve components are all the same, I am sending my cylinder, head, home made power valves and the piston off to Mick Abbey to be ported etc next week and will make a port map before and after and provide some pictures (assuming he permits this, I will ask 1st)

Base gasket - no different to R model from what I remember, R model fits straight on.

Cases - Cases have a hole in to incorporate the 2 stroke pump which is very easy to remove and make a blank up for... (does anyone need a 2 stroke pump? got one kicking about in the back of the car!).