1984 Sea Ray with dreaded 3.7 problems

[psdscoot]

I just bought a 1984 19 foot Sea Ray with the dreaded 3.7 motor. I wish I would have discovered this forum first. Took it out on the water and sure enough it overheated, I shut it down immediately.
After investigating these forums, I looked into the raw water pump and it's brand new, the motor and drive look like they were both maintained well. New bellows, hoses, etc. Screws and nuts all have been greased, etc. I did notice the engine has the dreaded 3 inch heat exchanger, could that be the biggest problem I have? I backed flushed the exchanger and it was clean. Put about a gallon of anti-freeze back into the motor and running in the driveway with the muffs on it sounds real good. Oil is clean, no water.
The second problem is the drive will not go down without me standing on it, it goes up fine. I haven't found much info on this issue.
The third problem is when I put the drive back on I made sure I was in forward gear but now it seems to only have neutral, what did I do wrong?
Any help is appreciated.

 

[jerryjerry05]

Re: 1984 Sea Ray with dreaded 3.7 problems

Nothing wrong with that motor if it's maintained right.Fill out the profile so we know if your in fresh or salt water.How long did it set before you bought it? How old is the riser?Risers only lasts 15-20 years.
Hook it to a hose or better yet put it in the water.Take a new thermostat with you.Unhook the feed at the thermostat housing.Was the drive installed right?Start it and see how much water is pumping.It should pump a LOT.
If not then the pump is suspect.Check the wear plates.Remove the exhaust bellows and check for rust/corrosion.
The drive needs lube!!!! Lots of WD on it spray it and stand on it run it up and down and spary it some more.Then do it again.J

 

[EddiePetty]

Re: 1984 Sea Ray with dreaded 3.7 problems


?After investigating these forums, I looked into the raw water pump and it's brand new........?

...which indicates, at least to me, that the former impeller was defective or had reached it?s replacement cycle. Remove the inlet (forward) end plate from the heat exchanger and inspect for remains of the former impeller. Back flushing has little chance of removing those debris.

?I did notice the engine has the dreaded 3 inch heat exchanger, could that be the biggest problem I have??

.....may not be your ?biggest? problem but certainly aids to it. Check Ebay, the 4" heat exchangers are frequently on there.


?The second problem is the drive will not go down without me standing on it, it goes up fine.?
.....most likely air in the lift cylinders. Have you checked your fluid level in the trim pump? Loosen a hydraulic hose fitting on each cylinder and push the drive down, replenish the fluid level (ATF is acceptable), re-tighten the fittings and cycle the system to purge air....repeat as required.

?The third problem is when I put the drive back on I made sure I was in forward gear but now it seems to only have neutral?....

......you probably didn?t have the lower shift shaft rotated completely and the prop locked CCW. (you?re most likely off by a tooth on the splined shaft)Read thru this and try again!!!!

http://www.mercstuff.com/alpharemoval.htm

 

[stonyloam]

Re: 1984 Sea Ray with dreaded 3.7 problems

You should probably upgrade to a 4" exchanger. Do a compression check and a cooling system pressure check to make sure that the engine overall health is OK (borrow tools for both free from autozone). Make sure your t-stat is working properly.
If you did not split the drive, most likley the little wheel at the end of the upper shift arm slipped out from between the arms of the shift slider at the end of the cable. Good luck, and welcome to the dreaded 470 club

 

[EddiePetty]

Re: 1984 Sea Ray with dreaded 3.7 problems

......Oh, and another thing just came to mind:

The flapper (shutter) valve frequently fails and becomes stuck in the outdrive (restricting exhaust and thus overheating). Inspect the interior of the prop and the cavity forward of the prop....if no restrictions there, remove the out drive (six nuts and a yank) and inspect the exhaust passages in transom area. And, while the drive is off...closely inspect the water supply hose from the outdrive to the transom for kinks and/or twist.

(There is a picture of a stuck flapper in the exhaust passge on this forum but I can't find it...hopefully the original author will re-post it)

 

[psdscoot]

Re: 1984 Sea Ray with dreaded 3.7 problems

You know I've been on a lot of different forums, diesel pickups, hdtv, etc., but I've never seen this quick of a response with this quality of answers ever. Thanks. I'll work on it later today, you know, after my day job. I'll get back to you on my results.