I recently bought a used Howard with a 525. When I first start the boat ( and crusing along for 10-15 minutes) the oil temp will climb to approx. 240-250 degrees for about 10 minutes or so then drop down to around 200-210 per the analog guage. Is this normal? Does the thermostate need to be changed? The water temp never goes above 170 on the analog guage and 153 on the Mercury Smart Craft. I don't think I have oil tempeture capabilities on the Smart Craft. Or at least I haven't been able to find it yet.