Hi guys. Im a student living in christchurch new zealand. Im looking at buying a k100rs on saturday. it has done 67000kms but im looking at offering him $500. What are the main things I should be looking at? It still has a plate so I should be able to re register it with a brake declaration. also he said the abs sensor wa faulty but that he had the replacement part.

Hi Ya welKome to the Knuthaus.  For $500 buy it

Welcome to the asylum from OZ. Bricks do not like sitting. Check and replace all fluids oil filter and fuel filter, clean air filter and replace if necessary. Check and replace all fuel hoses and vacuum lines, breather hose and vacuum caps. Check the condition of the fuel pump damper ( known to turn into Vegemite when left sitting in ethanol fuel) and fuel lines which much be rated EFI submersible. If you want to get serious about preventive maintenance and make life on the road easier, go over all the electrical connections with Deoxit. The four pin connector under the right hand side of the fuel tank is a known source of electrical gremlins and should be cleaned if not replaced by a waterproof quality one. The Brick if well maintained is ultra reliable.
Regards Martin.

ok thanks guys. im not sure how long its been sitting or if there is any maintance history. but he said its starts up first pop everytime.

Welcome!  $500 for 67,000km is a good deal in my book.  Definitely follow Martin's advice.  Also get into the drive shaft and lube the splines.  It's a good idea to pull the transmission back and lube the splines on the clutch as well.  The brain trust here has a pretty good track record of getting neglected bricks running, so you have come to the right place.  That it starts on the first try is a good sign.

I believe the electrics that drive the fuel pump enter the bottom of the tank on the front left side.  Well, they did on the 1985 model I had.

It has ABS so it's post 88 and just as Martin said.

$500 for a relatively low kilometrage  () K-bike? Having $1000 in reserve for replacement parts, a mechanical aptitude, a place to work on the bike and an abundance of patience all should be part of the picture if you get it at that price. You already have plenty of positive attitude.

cool guys thanks for the info and encouragement. so the ABS sensor shouldn't be much of an issue?

For ABS info see Tosi he is the guru http://bmwk10075abs1fix.web.fc2.com/