1974 75 hp chrysler water tube

celtic gelf

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Re: 1974 75 hp chrysler water tube

are you sure it's a 1974 and not 1975 I can't find a manual 1975 is the first year available
 

jerryjerry05

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Re: 1974 75 hp chrysler water tube

Why remove it??It's like any other Chrysler the powerhead needs to come off.
Under it is a water line bracket.It has 2 screws that hold it in place.They will be almost impossible to remove.J

Profile??
 

vt750dc

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Re: 1974 75 hp chrysler water tube

757ha is the model #. its just like my 757hc which is a 1976.
 

vt750dc

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Re: 1974 75 hp chrysler water tube

it runs hot on the water if you run more than half throttle for more than 10 or 15 seconds. already replaced thermostat,water pump impeller and head gasket. it will run all day long under half throttle; i just dont care for 15 to 20 mph; when it should cruise at 35. any other suggestions will be appreciated.
 

fucawi

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Re: 1974 75 hp chrysler water tube

it may be that you have exhaust getting into the water passages and that backpressure is pushing back the water ..common place for this is the exhaust side cover which is water cooled and can corrode through to the exhaust....
you need to fit a proper tell tail or as the yanks call it a pisser so you know whats going on in the engine
 

Frank Acampora

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Re: 1974 75 hp chrysler water tube

Did you replace the white plastic adapter on the pump outlet? Was it stuck to the water tube? Did it slide too far up the tube if you left it on (the tube) when you reattached the lower unit?

If this adapter slides up the water tube, most of the pump volume will be lost to the midleg and never go up the tube to the block.

The adapter has a ridge at the bottom and if it has slid up the tube, this ridge will be broken. Thus: in that case, you will need to replace the adapter.
 

vt750dc

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Re: 1974 75 hp chrysler water tube

how would i install the proper tell tail. and how would i monitor it after the install. thanks
 

vt750dc

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Re: 1974 75 hp chrysler water tube

i did replace the plastic adaptor when i replaced the impeller, after testing on the water i recheacked it and it was fine. i was worried about the copper tube because it seems too loose. is there any way to check it?
 

jerryjerry05

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Re: 1974 75 hp chrysler water tube

You mess with the timing?
If there is nothing stuck in the copper tube(old impeller) and it won't pull out.Then it's fine.
If you reef on it,it will comeout and be real tough to put back right.
Hook up a garden hose to the copper tube and see if it comes out the thermo housing.
In a big bucket the impeller under water.It should push a lot of water through the thermo housing.
You in salt or fresh water?Profile???
Older motors the exhaust covers corrode and fill with junk.Making it overheat.
Do these things and get back.
To take the cover off it's gonna be tricky.These bolt/screws been there 30+ years and won't come out easy. J
 

vt750dc

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Re: 1974 75 hp chrysler water tube

when i hook up the water hose to the copper ,tube water does come out the thermostat housing ( housing removed of corse). water also comes out all around the copper tube area inside the leg(quite a bit). I also took the plug out of the top of the head beside thermostat and installed a line with an 1/8 inch restriction hole, just barely drizzles water out when running. fresh water useage only. any way to hook a pressure gauge to it? i dont know how to set the timming; i know were the marks are on the flywheel timing tab and distributor thats about it. i build race cars. not boats, but would like to fix my own.
 

vt750dc

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Re: 1974 75 hp chrysler water tube

just pulled the exhaust cover, being gentle i still broke one bolt off; any way there wasnt any gunk or corrosion and the gaskets were in good shape; so tomorrow i replace the cover and look somewhere else.
 

fucawi

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Re: 1974 75 hp chrysler water tube

have you split the exhaust cover into two parts ..pulled off the stainless plate ? Whilst its off poke out the water passages and blow with compressed air .
 

jerryjerry05

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Re: 1974 75 hp chrysler water tube

You might have answered you own question,The extra water comming back down the copper tube.
There is a rubber seal at the top of the tube.Could be bad.The powerhead will need to come off.
 

vt750dc

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Re: 1974 75 hp chrysler water tube

thats what i was afraid of. does anybody care to help with the tell tail install and the max inside diameter line; and any info on how to set the timming.
 

vt750dc

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Re: 1974 75 hp chrysler water tube

just got done removing and replacing the power head and testing. alot of work and same problem, any other suggestions? thanks
 

vt750dc

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Re: 1974 75 hp chrysler water tube

went back to the lake, fished a few spots. last time i moved i putthe boat in forward and it started jumping in and out of gear and took off in reverse, so i shut it down ,trolled it to the trailer and took it home. the problem was the little brass shift dog broke and caused the problem. i took the lower unit off my spare engine, swapped the water pump impeller (only) out of the unit i was using into the the spare lower and put it back together. next day at the lake no more over heating problems. not quite sure what the problem is with the old lower, unless it has worn out plastic o-rings on the water pump housing, or a crack somewere that i cant find.
 

fucawi

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Re: 1974 75 hp chrysler water tube

Had a request from the OP on how to install a tell tail ( pisser) ..first locate on the head a blanking plug either square or allen key drive ..take this out ..may need heat ...the tread is a taper thread standard air line thread so I bought an air line fitting and silver soldered a suitable size pipe to it for my outlet pipe. Now where you squirt needs to be only about 1/8 dia 3 mm so you get a good strong jet ..you have about 10 -15 psi in the system...so I drilled a 5/16 ( 8mm) x1 1/4 bolt through the centre and turned off 1/2 in of the threads to get the pipe on ( you could file the threads off ) .....angle outwards on the starboard side where you can see it ...The strength of the flow particularly at idle will indicate water pump wear ...if it gets weak or only squirts above idle then its time to change the impeller...spot of grease in the end when storing to keep the animals out ( most important in australia )
 

Dtholz

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Jul 12, 2011
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Re: 1974 75 hp chrysler water tube

can someone post a picture of there pisser setup ihave a 75 hp chrysler that has just have water pump replaced but still doesnt throw water out the mid leg vent, removed thermstate housing and very little water flow, no thermostate either,,so thought a pisser would be a good idea . i have a second motor with a blown piston and noticed a small vent line on that unit next to themo housing could this be a pisser line ?
pisser .jpg

also i removed the exhaust housing on spare motor and wanted to know if water should flow through this housing it has a lot of mild corrosion between the housing and metal flange housing.jpg
 
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