outboard cooling

[FCnLA]

Billy D, I'm not doubting what you said. I don't have thermostats in my OMC, but I have restrictors (home made - take an old thermostat and cut the guts out and replace the outer portion). I do not use this boat in the winter. If it is cold or at start up I warm it up a while. The tolerances of the internals are set up to be at operating temperature. Unless one of his thermostats is malfunctioning, it should not be overheating.
So how's it coming obboy? FC.

[obboy]

looking for those 150 heads. What's your fuel recomendation Barry? 92 should be ok don't you think. Keep in mind I still run the stock oil injection pump. 150 heads with the comp gasket won't put my volume under 35cc will it? The 200 two piece heads are cut to 35cc. Centurions aren't the fastest hull on the water so ultra high speed is not the primary goal. I run a 21 inch High Five Merc 5 blade prop at 6200rpm. This yields about 60-65 mph on the twin 80mph Airguides. I have a CMC jack plate with your basic setback (5-6in.)and a max lift of about 6". It's fun but it aint no Allison!!!!

[Barry]

92 octane is the minimum for 35cc heads and 150 lbs max on premimum gas. It sounds to me your overheat problem has been solved now that you have a low water pickup. At high speed you were running out of water. You need a water pressure gauge to monitor your water pressure. Should have about 15 pounds at WOT. You never said if you have a nose cone or not.You must have one if you are jacking the motor up at all.
Barry

[obboy]

I've always run a water pressure gage. The nose cone and low pickup went on after I hit the overheat alarm the first time. Water pressure has always been good and I get good flow out of the discharge tube, but the temp thing is still an issue. My visit with the overheat alarm was extreemly short term and and there is no apparent damage from it. Like I said it runs fine at crusing >4000rpm. It just gets concerning at WOT. Thanks for the input!