Reno Del Ben has over 800k on his K75. He maintains it, and it still runs well.
Quick calculation: at 500k miles in 5th gear, the engine has done more than 2 billion cycles. :eek2:
From the K-BMW mail list;
Quote:
Just for the record, I't now 712,000+ miles on my K75. I just completed by second trip to Death Valley, CA, this year three days ago.
Reno A. Del Ben
Tenafly, NJ
1993 K75; 2005 R1200GS
This was posted as a follow up;
Quote:
Since you asked:
1) The original cylinder head was replaced at 327,404 miles with a salvaged head. This was done because I was down to a 2.05mm shim on exhaust valve #2, snd while I would be down to minimum clearance with the smallest shim available in about 20,000 miles, that would have been in the middle of the summer, so I chose to replace the head in January, 2001.
2) The salvaged head was not really that good, since, while my original head started with exhaust valve shims of 2.45mm, the salvaged head started with exhaust valve shims of 2.25mm, or half of the shims available as the original head (the smallest shim size is 2.00mm), so the salvaged head only lasted for 132,000 miles before I was out of available shims (valve clearances decrease as the engine ages, with the exhaust valve clearnces decreasin at a rate that is about 4 times the rate that the intake valve clearances decrease.
3) At 459,449 miles in February, 2004, I had the orignal head rebuilt, with new injectors and valve seats and the salvanged head was replaced. The valve seats on the build were cut so that I started out with valve shims of 2.80mm, much more than originally. At the time the rebuilt head was installed, new cam shafts were also installed.
A new timing chain was also installed -- but I consider the timing chain to be a normal maintenance item and it gets replaced about every 150,000 miles. The original head (albeit rebuilt) is what is now on my K75, and I expect it to last at least another 200,000 miles, based upon what size shims I currently have installed.
4) At 507,746 miles, in March 2005, I considered that my K75 had probably reached half-life, and that I should do some work on it. New pistons and piston pins were installed, and all bearings in the engine were replaced. At that time the fuel pump, brake hoses, thermostat, and throttle cable were replaced. Also replace was the water pump, which I again considerer to be a normal maintenance item, and the water pump gets either replaced or rebuilt every 150,000 miles. The piston skirts showed some wear. The cylinders were like new, with the manufacturer installed cross-hatching still clearly visible, and nothing was done to the cylinders.
5) The starter motor brushes were also replaced at 507,746 miles for the first time. The original alternator brushes and regulator were also replaced -- but the brushes and regulator I consider to be normal maintenace items which get replaced about every 150,000 miles.
So at this point the original engine and the original cylinder head (both rebuilt) are in my K75, and I don't expect to be doing any major work on the engine (other than normal maintenance items) for a long time.
Reno A. Del Ben
Tenafly, NJ
1993 K75 with 712,000+ miles; 2005 R1200Gs
