Water doesn't mix with Oil

F115 yamaha ,has been teaching me many lessons about LIFE. Changed oil and found it didn't look good ,too grey.Shop man said water in oil.Motor runs great Idles great, nofouling on plugs.Compression from #1 to #4 cyl. 155,155,150,148. The water intake on Exhaust jacket is salting up a bit and there is evidence of salt leakage on the port edge of the the headgasket between #3 and #4 cyl. Is there anything else I can check before Cracking into the head?

Check that compression with the motor warm and the throttle open and you should see around 200. Check the t-stat yet? The exhaust guide and all related gaskets under the powerhead are a more likely target in my opinion. Especially if your motor is an early F115 or if your motor is pushing a heavy hull and maybe over propped and not getting 6000 wot.

Thanks PBRMAN, I just changed T-stat and it was open.I havn't compression chkd it warm. Motor came off 17.2 KW and had 21p stolleto,and wouldn't turn 4800 rpm WOT.I just changed boats to a 18.5 displacement hull (Atlantic well skiff). I put an aluminum 19p and it runs at 5800 wot all the way down on the transom. Thanks for the feedback,your advice is always IMPECCABLE( Without Sin)

Thanks , MOONMAN60

If you run much of a load in that skiff you might consider a 17 pitch prop.

I hope this water/oil problem doesn't require lifting the power head but the more I investigate the more it seems inevitable.I drained 5qts of oil out and let all drain for hours to remove every drop and I noticed that there was no gasket on my drain plug .Could that have anything to do with milky oil? And I noticed,as the oil was flowing down the drain tube a number of dark small bubble like inclusiions about 1mm in dia. as well as splotches of carbon,not allot but present.I've never watched oil so intensley but I want to go fishing not over haul my motor!!!

Thanks for anyones insight.