[tbrown]

I am replacing my '86 750 motor this weekend, and had one question. At the shop from which I am purchasing the motor, they have done a compression test, and drained the oil to check for metal. Obviously, the best thing is a leakdown test, but will a compression test detect oil consumption. I ask because I once rebuilt a GPZ750, and although the compression was restored after the rebuild, it still burned oil like a champ. Any experience with these matters?

 

[SNAKEYES]

rebuilt engines will burn oil for a while till they are broke in everything is so tight it has to burn oil till the parts lossen up a bit and get seated. you can get compression if you drop oil in the combustion chamber it seals the rings for a while till the oil leaks by the rings. no compression test womn't tell you if it burns oil white smoke will.

 

[garef001]

remeber that the valve seals can also leak oil.

 

[customizedcreations]

Actually you ll have blue smoke if you burn oil, not white. White smoke means coolant/water being burned. A compression test can reveal bad symptoms, but you can have bad valve seals as stated and still have decent compression. A leak down testor is a great tool to use. If your rebuilding the motor, you will mostly likely pick up compression as the motor breaks in. If you rebuild the motor, and its burning oil badly , then chances are that something is wrong. Small haze is normal, huge mosquito fog is not.