exhaust coming out of the thermostat, 1970 evinrude 40hp?

Question

changed head gasket and impeller,still no water just exhaust, GRRR!

Answer 1

I have personally seen on motors like this, where a piece of the block at the cylinder head has flaked away. Mine was on a 1959 Evinrude 35 - very much like your Evinrude big twin. This is because a steel sleve is pressed into the block from the front - and is very close to the head with a bit of aluminum extending past - which can break off.

This gap allowed the compressed gas to leak into the water jacket - mine was bad enough the top cylinder had near zero compression. Took it to a competent welder who built up a bead. I then filed it back down to flush very carefully, and retorqued the heads back on - I got within 5 psi. Good enough for me.

Here's a photo of my motor before the repair.


Also, check to make SURE you can get water to run through the motor. Drop the lower unit again and see if you can get a hose to run up the water tubes and through to the thermostat. Alternately see if you can get water to run down the thermostat location and drain out the exhaust. Very likely you have had mud daubbers or some other insect block a water passage. Got a coat hanger?

Don't listen to JP Suzuki - these old motors can and do run well for many, many more years with care. My fishin' motor is a 1945 Sea King 5HP which starts on the 2nd pull or less.

At 37 years young, we don't even look at these motors for the club - too new. I'm running a 1946 and 1945 motor regularly.

Answer 2

Do as Mike D said and if that is not it, then take it back apart and check that you did not put the head gasket on upside down or backwards, some how exhaust is getting in the cooling system.
Which either means head gasket or cracked head.

Answer 3

Probable cause is your water cooling system is blocked. Remove the thermostat housing and remove the thermostat then run a descaling solution through the system replace the thermostat housing and a new gasket without the thermostat and run the engine. Check you discharge hose is not blocked first. Wear protective glasses. Did you check that you replaced the "key way" on the impeller?

Answer 4

do not anticipate its the worst case, examine the obtrusive first. i could do a leak try on the coolant device. If it dosn't carry rigidity, take it lower back to the place it grew to become into fastened and inform them to repair it corectly this time. If it holds rigidity drill a small hollow interior the muffler it would have coolant in it. under is rationalization of coolant in muffler. Years in the past I labored on the interior of sight oil / gasoline corporation. We replaced the pinnacle and intake gaskets on a 1970 F 800 with a 371 gasoline motor. It nonetheless blew white smoke after. earlier we could get it in to examine it farther, the branch supervisor had a interior of sight save come %. it up and take it to repair. supervisor informed us we had our possibility. the guy that owned the save is supossed to be the interior of sight Ford Guru! He replaced the two head gaskets lower back. that did not fix it, he rplaced the two heads with new ones. that did not fix it. He replaced the intake with a used one. that did not fix it. He then replaced the fast block ( finished decrease end of engine ) with a remanifactured one, claimimng there would desire to be a hair line crack interior the block, and that as quickly as we labored on it we would desire to have over torqued the pinnacle bolts. that's what brought about the crack. New motor nonetheless did not fix the subject. He sent it lower back 3 weeks later, with a invoice around the $7,000 area asserting he did not understand what it grew to become into. I jumped under it drilled an a million/8" hollow in the two mufflers, enable them to drain, started it, much less 5 minutes it stopped blowing white smoke.

Answer 5

Ok you did what you could the paitent died. Time of death... motor was 37 years old the old pusher did what it could.. Now go out and get a lighter faster more reliable electronic Yamaha or Suzuki

Answer 6

I think your head gaskets are gone!!! did you put on a gasket??