RB25DET compression question

[THE240guy]

Hey guys looking for some reassurance. I bought a 1996 240sx SE with a swapped RB25DET series 2 over the weekend. I am just going through the car making sure all is good. I did a compression test on it and my finding were 150psi across the board except cylinder 4 which had 175psi. I took my borescope and looked inside all cylinders and all looked good. Any thoughts on the one cylinder having 25psi more then all others? Should i be concerned at all? Thanks in advance!

[VStar650CL]

Standard compression on the RB25DET was 175, so #4 isn't necessarily high, the other 5 cylinders are low. They're still above minimum (130.5) but the 25 psi differential is way past spec, maximum variance between cylinders is 14.5. First thing I'd do is repeat the test wet-dry and confirm that the #4 reading isn't an artifact. If it isn't, how does the crown on #4 look compared to the others? Carbon buildup due to an injector or ignition issue can drive up compression on an individual cylinder.

[THE240guy]

@VStar650CL Thanks for the reply. I will clean everything and try again. The only thing i didn't really like was 25psi variance between #4 and the rest. I wasn't disappointed in the 150psi but will try the test again in hopes of a bit different reading. My plan is to run it on stock turbo a little higher than stock boost with intake manifold, intercooler, injectors and exhaust for the rest of the year then pull the motor and build it for next year.