1996 Four Winns Horizon 200

[kodyman84]

[No message]

 

[Horigan]

From your fourth picture at the thermostat I would disconnect the hoses to each exhaust and from the cooler and blow in them to confirm there are no restrictions. Do this with the outlet from the raw water pump disconnected so you're not flowing through the pump. Do the same from the inlet to the pump to back to the drive. I find blowing with your breath gives you a better indicator of any restrictions. You should also backflush the line from the oil cooler to the pump outlet from the thermstat. I know you did that from the pump, but I would do it reverse flow to backflush any crud out. Note that you likely have two coolers, one for oil and one for power steering, hence the upper and lower cooler sections in your third photo.

I recently went through a similar issue with a clogged heat exchanger, which you don't have, that involved flushing 50% muriatic acid through the exchanger for five minutes. You could try that through your coolers if it seems restricted. It involves using a spare bilge pump, two buckets (one for acid and one for water), and clear tubing. Google cleaning marine heat exchangers for the procedure.

Your issue could be corroded manifolds if they've never been replaced. They are consumable parts, even in fresh water.

 

[kodyman84]

Thanks for the input Rich! I will give that a shot.

I also just conducted another test. I went to Home Depot and got the biggest plastic tote I could find and filled it with water and then lower the drive into to submerge my inlet holes. I had the wife take video at the rear of the boat while I started it up. Absolutely zero water being drawn in. I turned it off and pulled both hoses from the impeller both are bone dry. I then started it up again with the plate off the back of the impeller. Verified that is indeed spinning. It’s also brand new, I inspected it after my tests and all of the fins are intact.

 

[kodyman84]

Okay so I’ve got some interesting results to report back on.

i used a short piece of garden hose I cut off to make myself an extension for the “blow” test. I blew in the hose that runs back to the drive from the impeller, because it was submerged in water still it was easy to tell that there was no restrictions as quite a bit of bubbling action occurred.

i then blew in the outlet hose that runs from the impeller to the oil cooler(s) again no restrictions and it was easy to do.

I then blew in both the hoses that come from the stat housing to the exhaust manifolds, both sides felt the same however it wasn’t as easy to blow in them as it was the other hoses.

I pulled the hose off the stat housing that comes from the oil cooler(s) and hooked it up to my garden hose to back flush through the cooler(s) and back to the outlet from the impeller housing....this came with a very strange result!! The water came out of the impeller outlet hose crystal clear....but it also came out of my stat housing at the same time! The only hose that was still hooked up to the stat housing was coming from the water circ pump, so I pulled that off and tried again. Water still came out of the hose and the stat housing, which means it’s coming from the block! How the bleep is that possible!

 

[kodyman84]

My mistake there is actually one more hose that runs to the top of the stat housing, but I’m not sure where it comes
from. I need to identify that!

 

[Horigan]

You need to check the flow diagram for your motor. See the link below for the OMC version of your motor since the engines and drives were common with Volvo in that era. It shows a circuit that could explain the flow out the T-stat. The site has similar diagrams for Volvo.

As I explained in another thread, you need water to the inlet of the pump, not just the drive in a bucket to get the pump to flow water. In a bucket the water level is below the pump and the inlet only has air in it. Impeller pumps aren't very good at pulling air up the inlet. It needs to be primed so the inlet is full of water. That's why you need muffs, to get water to the pump inlet.

It sounds like your exhaust manifolds may corroded/restricted. They should have the lower resistance than through the cooler. You can remove one of the elbows and check the condition of the internal water jackets. If it's heavily corroded, that's your issue. Have a new gasket ready in case it's good and you need to reinstall the elbow. Heavy corrosion also brings the risk of water entering the cylinders. That would be expensive...

 

[kodyman84]

Okay I figured that out. It’s and anti siphon hose that runs from the cooler to the stat housing. That explains how the water is getting there....phew!!

Unfortunately that gets me no closer to a solution.

 

[kodyman84]

So I pulled off the elbows for inspection and everything looked pretty good in my opinion with the exception of one small area of the port side elbow. However both port and starboard sides were both missing the exhaust flappers.

 

[Lou C]

Manifolds and elbows look fine. Def NOT a salt water boat, lucky.
put the boat in the water and disconnect the host that feeds the t stat housing. Start the engine briefly and then measure your flow....
keep in mind due to the Volvo style impeller the pump will not prime unless that hose from the transom is full of water. Normally with the boat in the water static water pressure will fill that hose. I think it should fill a 5 gal bucket in less than 15 sec for a simple test.

 

[kodyman84]

I’ll give this a shot as soon as I can. I’ve got to get the elbows back together first. Thankfully I have those gaskets handy.

What do you guys think about the missing exhaust flappers? There was no remnants of them on the pin, so I’m not sure if they got cooked and fell in or if somebody removed them at some point and left the pins instead of filling in the holes. Could those pieces be sitting in the exhaust bellows? And even if they were would it make a difference?

Also that anti-siphon hose that runs from top of stat housing to the oil cooler has a check valve in it, is it possible that had gone bad and is having some effect?

 

[Horigan]

Volvo released a service bulletin to remove the flappers. Since the pin holes are covered by the rubber seals, the pins can either stay or be removed I suspect.

While you have the elbows off you can put a garden hose in each exhaust below the elbow and confirm full water flow from the hose flows out the drive. This would confirm there are no objections/dropped flappers in the exhaust.

Not sure what flow diagram you boat has (carb or EFI), Ford or GM, etc), but I would think you could check the function of the check valve if you have access to both ends of it or ends of hoses from the check valve.

 

[kodyman84]

I ran the hose down the exhaust before I put it back together and it seems to flow out of the transom just fine. I Took the pins and grommets out of the exhaust y pipe before I put it together.

Going to try and do the head pressure test next. Unfortunately getting it back to the lake to do this isn’t an option today. So I’m going to try and get the pump primed on the muffs then pull off the muffs while the inlets are still submerged in my 55 gallon tote and see what happens.

 

[kodyman84]

Well I might have an answer or at least a partial one. When I ran the head pressure test it certainly wasn’t 2-4 inches of head. But more importantly I noticed that the impeller shaft seal on the pump is leaking. I’m guessing this would let air into the system and not allow proper pumping. Also noticed that the brass cam on the inside of the impeller isn’t symmetrical. Need to find out if it is supposed to be or not. First things first fix that shaft seal and try again

 

[kodyman84]

Well decided to just order a rebuilt pump assembly from eBay. By the time I bought a rebuild kit and a new cam along with all the tools I would have needed I would have been close to the $200 I paid for the pump. Should be here Friday this week and we try the head pressure test again. I could use a few days off of trying to get this thing going. Mentally frazzled!

I’d like to thank those who have chimes in to offer advice on my problem! I’ll post next weekend.

 

[kodyman84]

Every good saga needs a conclusion. Moral of mine was a raw water pump replacement. Had a bad shaft seal and bent cam fingers which allowed the impeller vanes to open sooner than they are intended. Combined this caused for poor water flow and my overheat condition. Ran the boat on muffs for 30 minutes and didn’t creep above 150, confirmed with a IR thermometer. Manifolds and elbows were at 105.

Thank you all for your help in finding me a fix!!

Anyone want to buy a boat?

 

[Horigan]

Glad you solved it. Now just go boating!