water circulation problem

[chitownborn]

hello iboaters, i got a water circulation issue with a chrysler 140 hp model no 1409h9. this motor has been sitting for twelve years in a garage, starts right up with a tap of the key, runs perfect just no water circ, because it sat for awhile with no use i changed the impeller, the fuel pump diaphrams & gaskets. the passage is clear from the thermostat down to the exhaust snout, i have a blockage some where between the water tube and the thermostat anyone have any ideas how to possibly clear it without having to pull the head & exhaust plate. i know its not the impeller or water pump cause i went as far as to change the whole lower unit with a known good pump. any ideas? thanks

 

[Frank Acampora]

Re: water circulation problem

Remove the thermostat housing and the thermostat. Drop the lower unit again. Use a 1/2 inch hose and clamp it on the water tube then turn on the water. If a good stream comes out the therm. hole, then you have no blockage.

If I remember correctly, the photo on ebay showed it as a one piece lower unit. These things can be a bear to prime on muffs. You usually need a strong stream to prime--but you know that with your 125. So with the therm back in place but the hose still on the pipe, turn on the water and start the engine. Water should almost immediately start to spit out the idle relief holes.

If it does, try again with the lower unit back on. BUT before you remount the lower unit, pull the pump and be certain that the impeller key is in place. Smatter of fact, If you turn the shaft in neutral with the lower off the engine, you should be able to feel the resistance of the impeller turning. If the shaft turns easily, then it is a good bet that the keyway has either slipped during installation or you forgot it---Da Da Da LOL Hey! Stranger things have happened. All of us has at one time left the drain plug out

 

[chitownborn]

Re: water circulation problem

thanks frank , il give that a try, next weekend. yep you remember correctly its a one piece lower unit, i do remember installing the key for the impellor, but like you say stranger things can happen, i even took the lu off the 125 and put it on there still no water circ. and i know that one is good lol. thanks for the tip,the motor is in pristine condition, all original chrysler parts and it appears not one bolt taken off paint isnt broke at any one bolt. il keep you posted don

 

[chitownborn]

Re: water circulation problem

ok, went and dropped lu again hooked up water hose to water tube made an adapter so to no leakage when pressure is applied, so at full hose pressure not a drop of water at the thermostat, left the hose running at full pressure for an hour, well when that didnt work i hit it with a high pressure hose, nada i mean nothing, could it maybe,possibly, i hope, the high pressure relief valve or do i have one hell of an obstruction thats gonna require pulling the head?

 

[Frank Acampora]

Re: water circulation problem

Since you have access to tools, make an adapter plate to cover the thermostat opening and try to blow it out back down the water tube.

The water comes up the brass tub, makes a 90 degree turn in the match plate, then makes another 90 degree turn at the "screw in pipe plug" up into the block. At this point the passage gets smaller so it is likely that the blockage is there.

Unfortunately, you will most likely not be able to unscrew the pipe plug in the side of the match plate. They must be permanently glued in. I have have tried and have NEVER been able to remove one. the square top always rounds.

The pressure relief valve in the side below the exhaust cover (actually in the dogleg) bleeds off excess pressure but was later discontinued. EVEN if the passage clogs with corrosion, it will not affect water flow to the block. Unless you are very careful and lucky, the two 10-24 bolts that hold the valve cover will snap off and then you have a real pain in the ---donkey. So let that be the last and most extreme effort at restoring water to the block.

If you absolutely can not clear the blockage (which may be a broken impeller vane) removing the head will most likely not help. Since water flows through the exhaust chest first, and since the entrance to the block is pretty much the smallest diameter, the most likely area to be clogged would be the entrance or the cover itself. If the engine is in excellent condition, it will not be difficult to remove the cover but more than likely you WILL snap a couple of bolts. You know the drill---

If you are not getting any water and it does turn out to be a part of an impeller, then you know why the P.O. was selling it on ebay for so little. Check the compression. These engine will start well even with a bad cylinder.

Hope this helps some. BUT:

Now I am worried about turning you on to it.

 

[chitownborn]

Re: water circulation problem

all right then, il make some kind of plate for the thermostat hole and try to blow it out that way. now that i know how the circ system flows,[thanks to you ] i know now il get the obstruction outta there Frank you da man!!!!!! [dont worry bout nothin] thanks

 

[chitownborn]

Re: water circulation problem

happy days are here again, got the obstruction out!!! got the pipe plug out with a little heat and a good plumbers wrench, that was clear and clean so really reluctantly pulled the exhaust plate, expecting every bolt to snap bolt on the dam thing, the outboard gods must have been with me not one snapped bolt. the exhaust plate was packed i mean packed with sand, peebles, mud, and some kind of furry stuff. cleaned it all out that took awhile, but still no circ to the thermostat so pulled the head, no snapped bolts there either, the water channel along side the cylinders was also packed with crap so cleared that out to along with every port, channel and tube all passages are now clear, now comes the waiting game on gaskets, Frank thanks for all the advice!! Don