Autonerdz forums

This is a cranking compression waveform from a Suzuki DRZ400. I am trying to understand why it looks like this. The valve clearance was out, the 1 exhaust bucket and cam lobe is badly worn so obviously the valve timing is out. The engine was turning over very slowly and uneven as the starter is just about baked as well. I do not understand how it can have 2 peaks. It looks like the exhaust valves were not opening but they are, Any thoughts?

Does the DRZ have a decompression valve? New to picoscopes but that may be your second peak.

Here you are. A little history. Bike was brought in mostly disassembled for a valve adjustment only and I did an in cyl compression check before I took the valve cover off. - Bike had no flywheel pickup or stator, ign coils, cdi etc, as customer was doing some work on it.  basically just the starter as far as electrical which was also on its last legs. So I couldn't reference the comp waveform to anything. It is really just a curiosity as to why it look like it does as the problems were obvious and have been addressed other than I am still waiting for cams.

Sorry, don't know bikes.  Is this a four stroke engine?  Could you post up some system operation?

Yes, it was the Beta software. It is a single cylinder 4 Stroke double overhead cam 4v engine. Cams operate the valves via a bucket and shim arrangement. Had a decompression release but had been removed as they were aftermarket cams.