1 Engine block wear Thu Aug 09, 2012 12:40 pm
shay
active member
Hi,
I recently installed new piston rings in my 1989 K100RS.
The reason was low compression in cylinder 4 (120psi) and avrege 130 psi in the rest.
When enegine head was off i sent it to a pro to treat the valves and to change the valves oil stem seals.
Before i did the change the bike wasn't burning any oil.
After i rebuilt the engine the bike started and engine works smoothly except it heavilly burns oil during accleration.
compression in all 4 cylinders is good 150psi
When pistons where out i visually checked the cylinder for wear of the nickaseal
coating and it wasn't shown with an unnaked eye,also when putting a new ring inside the cylinder to search for signs of ovalness,ring fit nicely and no light was passing through the gap between the ring and the cylinder wall.
i'm telling all the story since i was told by a local bmw dealer that this models when reach high milage tend to get oval shaped cylinders which causes the problem.
i'm about to take the engine head off again hoping the problem is from that area maybe an oil seal from one of the valves?
Any ideas ???
I recently installed new piston rings in my 1989 K100RS.
The reason was low compression in cylinder 4 (120psi) and avrege 130 psi in the rest.
When enegine head was off i sent it to a pro to treat the valves and to change the valves oil stem seals.
Before i did the change the bike wasn't burning any oil.
After i rebuilt the engine the bike started and engine works smoothly except it heavilly burns oil during accleration.
compression in all 4 cylinders is good 150psi
When pistons where out i visually checked the cylinder for wear of the nickaseal
coating and it wasn't shown with an unnaked eye,also when putting a new ring inside the cylinder to search for signs of ovalness,ring fit nicely and no light was passing through the gap between the ring and the cylinder wall.
i'm telling all the story since i was told by a local bmw dealer that this models when reach high milage tend to get oval shaped cylinders which causes the problem.
i'm about to take the engine head off again hoping the problem is from that area maybe an oil seal from one of the valves?
Any ideas ???