PUMP or T/Stat ?

Got be a better way...I do have the book on this one but not very helpful. I’ve been around OB engines a long time but this is the first time on this animal. Before I break down the lower unit I want to make sure it’s not in the T/S. This is a 1972 85 HP RUDE, very rude. This is the one that has the T/S at the bottom of the block. Has two short hoses going to each side of the V4 block. I can run it all day long on the earmuffs and runs nice and cool, when I put in a barrel no water pumping, and yes it’s deep into the water. I then opened the stat housing and removed the inner junk, still no water. Is it the pressure from the water hose that’s pushing it into the system? Or could it be in the T/S itself? Most engines when the T/S is out there is no problem. Not sure if this one needs the complete system intact.

Re: PUMP or T/Stat ?

Sounds like you need a new water pump runnning a motor flush you will have water flowing with or with out the pump.<br /><br />Bill

Re: PUMP or T/Stat ?

Well...here's what I think...the pressure from the hose is making the water circulate which keeps the engine cool. Now if you put the engine in water and she gets hot even with the t-stats removed...I think it's time for a water pump overhaul. Since you have the t-stats out, replace them to and make it a well rounded job.<br /><br />Keep us posted.

Re: PUMP or T/Stat ?

Thanks guys. This shop manual states that the cooling system is under pressure, that's why I asked if it would work without the T/S in line. It's just my own stuff I play with, not for others. Anyway the part about the pressure is what I didn't understand. Seeing that it's not a closed loop like a car.

Re: PUMP or T/Stat ?

If you haven't been into the lower unit before just go ahead and order the whole water pump rebuild kit.<br /> I have one thats a 76 and I tore it down and the plate and grommets were in bad shape. The cap was in fairly good shape but sure was glad I had ordered the whole kit.Now I have a spare cap if I need it.

Re: PUMP or T/Stat ?

Re: PUMP or T/Stat ?

Ya just gotta love this engine I removed (all) the bolts that holds the lower unit in place. Whacked it with hammer and block of wood till the cows came home, used a putty knife to break the seal, and still won't separate. I can see daylight and it looks like it should come apart, but it's a no go. Is there any magic trick I need to know before I bust the casing?

Re: PUMP or T/Stat ?

I can't remember if this is true or not on your 72, but on my 76 you have to disconnect the shift linkage from under the carbs. Look thru the shifting cable and there is a 5/8 bolt head you have to remove that and the pin slides out of the shifting rod.<br />when putting it back together the cooling pipes have a plastic sleeve that serve as a line up for the tubes.

Re: PUMP or T/Stat ?

I have a 74 85hp. I had the same problem. I missed a bolt. Then it dropped right out. Also make sure that you undid the shift linkage. But even with that in, it should seperate a half inch. I think you missed a screw. Use the manual.

Re: PUMP or T/Stat ?

This one is electric shift no rod..I can wiggle the front portion and it looks like its hung up in thr rear, (back side) not the prop end.