Block was machined and assembled my a reputable shop, head was taken apart & inspected then just had the valve seals relaced (honda valve seals) It seems to burn oil on deceleration. I had it idling the other day for maybe 10 minutes then moved it and as soon as I touched the gas (not high revving, just enough to get it moving in first gear) it let out a fair sized puff of smoke. Also, at the track people notice it puffs when I let off the gas then hit it again. Under normal daily driving it goes through a liter within 2500 kms or 1500 miles. I have a friend with a GSR and he got new aftermarket valve guides pressed in, he claims the GSR heads specifically have poor valve guides. My motor had over 300,000 kms or almost 200,000 miles at the time of rebuild.