VP 145 w290 outdrive from hell

"Hello EL and all else,

I

"Hello EL and all else,

I am trying to upload some photos here to show what I'm workin with. I don't now if it worked.

I checked to raw water supply hose and it is tight. I installed it best I could when the outdrive was off. Here is something new, this last time running it I noticed that the boot that links the exhaust manifold to the exhaust pipe leading out was leaking water runing at higher RPMs 2500 - 3000. . what would be causeing back pressure or a restriction in the water escaping from the exhaust at higher RPMs. I say this becasue when I am at idle it doesn't leak. So I tightened the heck out of it and will run it again Saturday.

I am changing the heat exchanger this weekend to see if that will stop the overheating problem. Oh (for anyone new to my problemo) if you didn't know I'm having an overheating problem with my motor when I try to get up on plain. It runs fine at idle, temp. levels off but when I throttle up the temp begins to creep up and when it's in the water with a load it really heats up quick and if I do not back down it blows a freeze plug}.

Does anyone think that the thermostat has to be in? The guy I got the motor from cut the valve out so water runs through it continuously. I'm in FL. Some motors have to have a certain amount of back pressure to run properly.

Pictures I think are attached.
motor pics"">outdrive

"Hello Wydel,

I'll try

"Hello Wydel,

I'll try to answer all or most of your questions.

Rearding a water leak around the exhaust hose, it could be due to back pressure as you suggested, but it could also be due to a perforated hose, a wasted exhaust manifold or a wasted exhaust pipe. My suggestion is that you remove both clamps, then slide the hose towards the aluminum exhaust pipe and examine the exhaust manifold and exhaust pipe for corrosion wastage. If either of them is in bad condition, then you know what the problem is and how to deal with it. If there is no corrosion in either area, then remove the exhaust hose (you should be able to slide it between the manifold and the exhaust pipe) and inspect it for cracks and holes. If all OK, then you could have an obstruction at the bottom of the exhaust pipe (unlikely) or somewhere in the exhaust passages in the intermediate or lower housing in the outdrive. If the exhaust bellows is the type that has an exhaust flapper, that flapper could be either stuck or have become loose and move inside the outdrive.

Regarding the thermostat: is should definitely be in, and it should be installed the right way (if you install it incorrectly, then you won't be able to attach the housing between the expansion tank and the head!!). Also, unless the heat exchanger is choked solid with scale or perforated, it should not give you many problems. However, you may want to make sure that the circulating pump is working well: a good indication is to remove the expansion tank cap, start the engine and accelerate (you should see the water level going down) then decelerate (water level will likely go up). Also, make sure the alternator belt (which also dives the water pump) has the correct tension and is not slipping; and that the raw water strainer is clean.

Overheating issues on the OHC VP engines have been discussed many times before, and virtually al the possible causes have been covered. You may want to have a look through some old threads, as I am sure they have the answer to your problem.

Good luck.

http://www.marineengine.com/discus/messages/12487/24902.shtml

http://www.marineengine.com/discus/messages/12487/81833.shtml

http://www.marineengine.com/discus/messages/12487/23242.shtml

http://www.marineengine.com/discus/messages/12487/25084.shtml

http://www.marineengine.com/discus/messages/12487/84746.shtml

http://www.marineengine.com/discus/messages/12487/86412.shtml

http://www.marineengine.com/discus/messages/12487/82340.shtml

http://www.marineengine.com/discus/messages/12487/85849.shtml

http://www.marineengine.com/discus/messages/12487/80294.shtml"