i pulled the cooler off and flushed both sides of the water and oil. it flows freely. I also reinstalled it and ran the boat with the drain plug out of the cooler to check flow. it does flow water but it is pretty warm water so I am assuming that it is trying to dissipate the heat. am I looking too far past the cooler simply not being adequate? there are no bypass valves to change the adapter is the correct one, all the lines are ran right and the only other dispute is that the oil runs to the filter before the cooler but thats how it was rigged on my other motor and this system worked fine?:drink:

Lake,
Are is your carb and jettting the exact same as before he rebuild?

yes the jetting is the same. it is not a rebuild this is a totally new motor. I started witht the same jets and was going to work from there. the plugs are nice and brown with no hint of detonation. if it was detonating to the point of heating the oil wouldnt you guys think there would be some splatter on the plugs? or at least the plugs look white? the oil temp will heat up to 140 while letting the boat idle for a bit through the no wake zone. as soon as I get the boat up on plane the oil temp gradually inreases and will continue to inrease until I slow down. when I slow down and go through an idle zone the oil temp doesnt really come down like it should. the temp will decrease but not like it did with my old motor. the only way to get the oil to cool down totally is to shut the motor off and let it sit for awhile. the is the exact same oil system that I had on my other motor and it worked great. If the bearing clearances were too tight wouldnt the oil cool down at idle? I can let the oil ccol with the motor off and after starting it again it will idle all day at 140-150 degrees of oil temp but as soon as you get up on plane it heats back up?

I am going to a lighter weight oil and try reducing the oil level by a quart to see what happens. I know no one on here like fram filters but I am also going to try the hp4 filter instead of the mercury filter. At this point I guess its a process of elimination:lolhit:

how much water pressure are you running? Are you running a thermostat?

no thermostat and I have about 2-3 psi at idle. should I try a thermostat to increase water psi and slow the flow down through the cooler?

or at least a restrictor?

interesting.I'm having the same trouble with new 632's.Almost identical set up to you.Dart block,canton adapter,18x3 cooler,an12 lines,canton offshore pans,oil senders in the pan,crossovers and no thermostats at present due to water pressure issues.First lap and on it went to 260,slowed to 5000rpm and came down to 230.I too am wondering if the cooler is too small.I'm not sure about a restrictor.Definetly need a thermostat to get the motor temp up.

It depends, how much PSI are you running underway?

well I just tried a 160 degree thermostat and all that did was raise the oil temp.