79 chrsyler 75 hp impellar ?

[milkman1258]

hello people I have a 79 chrsyler 75 hp motor and im trying to change the impellar.so far i removed the lower unit and the 4 bolts to the housing, my question is does the housing slide over the upper part of the shaft or do i have remove the shaft and slide it out that way?i bought the motor last year and it ran great so far this year its still running good but a alarm went off like if was over heating or something.it was spiting water out the ports like it always has.the alarm seems only to do it at WOT.the alarm sounds off for about 5- 10 then quits. then i restart the motor its fine as long as i dont go WOT. the impellar looks new and seems to be in good shape as for as i can tell. im just wondering also could it be poor fuel mixtured? i do a 50-1 mixture but i dont use a real accurate measuring device could a ounce too much or less make a difference? thanks for any i can get im new to this boating stuff but i am average mech.

 

[Terry H]

Re: 79 chrsyler 75 hp impellar ?

Milkman...The impeller and housing come off over the drive shaft no problem...if it is overheating at wot you might also check the thermostat and pressure relief valve...replace parts as needed and make sure all water passages are clear of debris...just a Thought

 

[12Footer]

Re: 79 chrsyler 75 hp impellar ?

Welcome to iboats and boating.<br />Something I've heard and found to be fact is, the impeller allways looks fine...Until it desintegrates.<br /><br />Best change it out, and check the rest of the cooling circuit as Thought101 sugjested.<br /><br />Also, check the sender. A bad sender,or corrosion around the sender can short it to ground. When that wire going to it is grounded, your alarm will sound. Check it with an ohmeter cold, and the wire off he anode. It should read open from it's anode to ground.If it shows any resistance, change the sender.<br />As for the fuuel mixture, of course you want to be acurate. Too little oil,and your engine will grind itself to death. Too much, and the plugs will foul.<br />An ounce or two in a 3 or 6 gallon tank could be critical.<br />An ounce or two in a 50 gallon tank will not matter...much.

 

[milkman1258]

Re: 79 chrsyler 75 hp impellar ?

thanks for your input guys i will finish changing the impellar. do i need to use some kinda lube?<br />also im sure what your talking about when you say sender? what is it? and where is it located? also where would the thermostat and the pressure relief valve be located? also how do i check the pressure relief valve? thermastat i can put in hot water right? as for the fuel mixture i will have a more accurate measuring device in the future.im still wondering to little oil in gas would make the alarm go off? i have 2 six gallons tanks. i did use a cup what i believe was 8 ounce i put 2 cups per tank.thanks again any help would be appeciated.

 

[12Footer]

Re: 79 chrsyler 75 hp impellar ?

The sender will be called a thermostat in your manual, and is located at the bottom on the head, with a single wire attached to it. (What on Earth posessed them to call it a thermostat, when they got a thermostat and a thermostat, is beyond me), but it is a sending unit,sender,tranducer, thermistor....Anyhoo, if you turn the ignition key to "ON" and touch the wire on it to ground, your alarm will sound.<br />And your manual will call the pressure relief valve a "Bypass valve" or somethin like that (has the word "Bypass" in there for sure). I don't have a copy of your manual here at the house, but if mam serves me (rarely does but...),it is proly located on the port side someplace on trhe exaust port plate or thereabouts.<br />It's really builders choice on some of these terms (sender/sending unit/transducer/thermostat/thermistor,samey-same.