Compression test fun

[Craig380]

My 380 developed a small leak from the head gasket of the centre cylinder, with oily smears visible. It's because of a loose head stud, which I'll fix over winter.

However, it's still running great and hasn't lost any performance. So just for fun I did a compression test after a ride at the weekend. Left: 132psi Centre: 135psi Right: 134psi.

It goes to show something, I'm not sure what that is, however

[titan performance]

Back in the early 80s, I was always cracking heads on my 500s, and like you, I would end up with oil misting all over the place....but the bike still went well, with no detectable loss of performance.

[Craig380]

Are the 500s prone to cracking heads? Where on the heads do they crack?

[Suzukidave]

Lots of great 500 info here http://www.ozebook.com/compendium/t500index.htm" onclick="window.open(this.href);return false;

[ja-moo]

The speed of the combustion cycles is just milliseconds, and the area of a crack so miniscule, you won't see any difference in compression, until it's in 2 pieces, then you will see a big drop......