77 70hp seahorse johnson

[16ftsunbird]

So i purchased this 77 Maquis with this 70 hp (model # 70el77s) seahorse on it after starting the engine iran it for a few mins but could never see water coming out it does not have a tale tell on it but has a sensor with a tan wire coming out so i asume it is a a heat alarm but never come on head seemed to get pretty warm so i cut it off. Today i carried it to the river set the boat in the water just to ck for leaks and again ran the motor a few mins test touching the head & again seems to be pretty warm no alarm so i'm thinking thermostat & water pump whats involved to do this job i have no boat motor exp but i'm a G.M. tech help me please

Thanks in advance Billy

 

[fireman57]

Replacing the tstats and impeller are not that bad a job but I will tell you to get a manual for your engine as it makes it easier. You could have a bad impeller or junk clogging a tstat. When the engine warms up you should be able to hold a couple fingers on the head for a long 5 count. If you can't then you are overheating. IF you don't know the last time the impeller was changed I would start there.

 

[alangore]

I am an auto tech myself, I just recently replaced the impeller and thermostat on a 1976 70hp. was no issue at all. just make note of which way the impeller vanes are angled prior to removing it. makes it much easier when replacing it. Good luck

 

[Boat Doctor1]

run it in lake- have someone view the 2 holes below the cowling @ rear of engine-water should be coming out of those when running hard !! there are temp stix & infra red temp measurement devices you can buy too!! usually until running hard will anyone see the water flow from those 2 holes - checking with a hand or guessing always makes for un needed repairs!!

 

[16ftsunbird]

so i carried it to the river yesterday all that was coming from holes was a light blue smoke.I assume u remove the bolt at the bottom of the bottom carb then remove the 5 bolts at the bottom of foot & everything pulls down from there?do i need to have motor in netural or a gear when doing this & also do i need to hold any kind of linkage with a string or anything when pulling it down. Is there a complete kit to do this job or do i have to buy seperate

thanks for all the help Billy

The wife says if we gonna own a boat i got to know how to work on it

 

[V153]

Ground the lead from the temp sensor. If the alarm sounds it means the circuit is good. Provided the sending unit's good this should tell you when/if the motor's overheating.

 

[16ftsunbird]

As i was asking is the bolt at the bottom of carb and the 5 around the foot all that has to be taken loose also is ther a complete kit to purchase or is it bought in pieces do i need string to hold any thing in place while i remove the foot so it can be pulled back in place when ready to reinstall want to start this tommorrow evening

thanks for any answers & all the help Billy