1977 evinrude 140 hp thermostat removal

[ozzgood2001]

whats the trick the lower cowling seems to be in the way. i can get the three bolts loose but i feel im not gonna be able to get in there and get it clean like i want. any help or tricks greatly appreciated

 

[emdsapmgr]

Re: 1977 evinrude 140 hp thermostat removal

The current flat rate on that repair is something like 3 hours, enough time to completely remove the powerhead in order to replace the thermostats. Most do not, but struggle on this job, as it is a bear. On this early engine, you probably can remove the two midsection cowlings, the loosen the lower cover cowling. When it's loose, you may be able to push it downward to get slightly better access to the stat housing.

 

[LiLGrady17]

Re: 1977 evinrude 140 hp thermostat removal

It should be the same as my 85 hp. Below the lower cowling is another cowling, bridging the gap to the lower leg. It's held on by 4 bolts on the transom side of the leg, plus 2 more inside the lower cowling going down, under the bottom of the heads. With this cowling removed, you can use an offset box end wrench to get at the 2 thermo housing bolts. Be very careful removing the bolts though, as in snapping a head off, or the bolt head actually disintegrating, you will be required to drop the lower cowling to drill out the bolt.. I haven't done my stat just for this reason yet..

 

[ozzgood2001]

Re: 1977 evinrude 140 hp thermostat removal

yeah the only way i can get to the bolts to drop the cowling would be to remove the port cylinder head theres bolts up under there attaching the cowling. i read a lil about drilling three holes in the cowling to get at the bolts im think this might be my route.... we'll see suppose to have the stats in the mail today from iboats.

 

[LiLGrady17]

Re: 1977 evinrude 140 hp thermostat removal

The holes in the cowling idea sounds good to me! Hit an auto store for some rubber bulkhead grommets/plugs, then you can drill the appropriate sized holes the first time.. I was able to get in to my bolts with a 3/8 wobble extension with a specialty socket with a universal joint built onto the socket itself..

 

[66 joe]

Re: 1977 evinrude 140 hp thermostat removal

THE JOB IS A BEAR!!! took me bout 6 - 8 hrs to complete, but after removing and seeing condition of tstats, 1 head was 155 and other 115, Im gonna change or inspect every 5 years. And I flush after salt every time.
getting them back on is harder then removal. i used lots of silicon and put two pieces together 1st along with bottom gasket, siliconed overnight in vise. Surprisingly, no leaks!!! Good luck, its not easy

 

[ozzgood2001]

Re: 1977 evinrude 140 hp thermostat removal

well i went with the drill holes plan its still a BITEWGERBGVRBEBF$%%^^&!! lol but got her done starboard side was running cold for a reason stat was stuck open on that side. taking the water away from the port side making it run warmer! all better now!

click the video you can see the drilled holes


stuck stats

starboard side after

port side after