4 cyl Volvo overheats at idle now freshwater in cylinders and out of carbs

"4 cylinder Volvo temp ok at a

"4 cylinder Volvo temp ok at all higer rpms but heats rapidly to 200 f during idle.

Went as high as 225 f today after 5 minutes of trolling.

Ran fine back to dock, 11 miles and cooled right down to 190 in one minute or less.

We took a break for lunch, boat sat at mooreage for 2 hours. I had a brand new volvo raw water pump so I replaced the old one . The Key was in back wards and some wear on old pump but still looked functional.

However when we tried to start with new pump massive amounts of water came out of both carbs.

what happened?

bafe"

"If it si fresh water what you

"If it si fresh water what you are getting out of the carbs, either the head gasket is blown or the head is cracked. There is also the possibility that water from the head is going into the intake manifold. What model of engine do you have?"

"Thnaks El Pescador, it is tw

"Thnaks El Pescador, it is twin carbed and past records state it is a 151 bobtail.

that is all I know , it has freshwater cooling and the water out of the carbs has no visible antifreeze in it. However the volume is massisve so it may be deluted.

Boat is an '82 Bayliner 22ft Trophy with a 270 outdrive.

bafe"

Would not be surprised if Your

Would not be surprised if Your timing belt has jumped some teeth on the gears!

"Did you by any chance do any

"Did you by any chance do any "dieseling" when shutting off and having engine possibly running one or two revolutions in reverse - thereby sucking seawater. Can happen if you don't have the flaps working over the exhaust port on the drive...
In any case you likely have a serious case of "hydro lock", in worst case with bent rods..."

"Thanks Per Ola and Morten, it

"Thanks Per Ola and Morten, it did not diesel at all and the flapper is in great shape. Changed manifold but the old one had no apparent leaks.

Water out , changed oil . pluges but not building compression. Morten will check timing belt for correct setting. After trying to start off and on for 3 hours I thought of your comment on timing belt jumping a bit . Batteries never ran down so even I can figure no compression at some point. Also getting weak spark , read manual and it states ( too late) to ground primary side of coil, how do you do this?

Per ola I hope the rods are ok , any other suggestions?"