78 merc 7.5hp t-stat removal

[suzukidave]

hi, i'm on an island on a dialup connection. i've been trying to revive an old merc 7.5hp outboard that runs great but won't pee. i replaced the impeller and now it drips. i've tried warming it up and running it under load in fwd and reverse. i think the impeller is in right so i'm wondering if maybe the t-stst is stuck as the motor has never been serviced since new. can i pull the t-stat to test it or do i need a gasket kit if i pull it (i've got some silicone engine seal)? also where is it on this motor?

other possibility is wrong impeller. the merc dealer gave me two saying he could not tell which from the p/n. one seemed to fit "just right" on the shaft while one was so tight i thought it would distort pushing it on. i went with the one that fit just right. i did also fit the woodruff key thingy into the shaft.

thanks for any tips

 

[goldstem]

Re: 78 merc 7.5hp t-stat removal

I'm not sure that the 7.5 has a thermostat (my 1972 7.5 didn't).
take a very small wire and with the motor idling push it into the tell-tale hole back and forth to make sure it is clear. very common for the hole itself to get clogged up.

 

[suzukidave]

Re: 78 merc 7.5hp t-stat removal

goldstem, thanks for the tip. the tell tale was completely blocked with salt. she now pees like the proverbial racehorse. many thanks again...