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Just remember the engine is brand new. It's not sealed yet, and no matter how much you will crank it now, the oil will not fill all the gaps otherwise it would and then stay there after being turned off. 0n top of that - it is cold. The head will also need re-torquing once it gets hot and cools down. You said they tested the head, and the block has been done as well (deglazed, new rings). There is really not much around there to fix more, all is done.

I have no idea what the numbers should be in this situation, so just based on the work done, if all done correctly and there are no hidden defects like cracked block or damaged gasket, I'd personally leave it as is. I haven't seen the bike up close though. Did you reuse the head gasket? 0r got a new one. I suppose all is sealed and tighten with proper torque.

Yep, new gasket, sealed with very little sealant just around the waterways, torqued correctly.

I'll leave for now. Once I have it running and have a couple of miles I'll re-check.

Paul

I followed up on this and I think this would be the best quote I found:

My last rebuild on my KZ650 I installed a big bore kit. After I got it all together my compression was really low below 80 on all cylinders. I got it started and broke it in. After about 500 miles my compression went to 170 PSI on all cylinders

So, not to repeat myself, in short: the cylinder rings are not properly seated yet in the cylinder sleeve (not sealed yet), no oil, cold. I wouldn't worry and run the engine until it brakes in fully after a 1000 miles. I have a feeling it will be just fine, and you will not even think about checking the compression again. It would be interesting though and I am sure you will be tempted.

0ne thing to add is to do a proper brake in and the initial maintenance when the time comes.

Another note that just popped up in my head. When I cranked the engine after rebuilding for the first time (but in frame and all hooked up to the controls and indicators) it showed the red oil pressure for a while. Then the light went off as the oil got distributed. Every time I cranked afterwards the oil light behaved like it should - red when key inserted, off soon after a crank.

Fast forward to the first 'real' start up. The oil light lit up red for a considerable time after the engine started running. It almost made me worry. Then - suddenly went off!
Since then, it's been just as it should - red on the key in, crank, goes off immediately when the engine starts.

This just shows how much is needed to really distribute the oil to all the places where it should be, and 'real' pressure of a running engine is needed to accomplish this. 0nce done, despite oil dripping to the oil pan when off, there is lots of oil trapped in all the different tight places around it. And don't forget the viscosity! And that includes the piston rings. Dry cranking the engine like you did will not seal it with oil.

It just shows how important is to have the engine running to evaluate certain things, and how much it affects it. Same with the compression test. The engine needs to have some mileage to truly evaluate certain things.

Are you holding the throttle wide open when checking the compression?

Its just an engine... nothing attached, not even carburettors.