steviecops
Chief Petty Officer
- Joined
- Oct 3, 2003
- Messages
- 585
I'm about to fit a new thermostat to my 1980 Johnson 55, but first of all I need to get some advice from the very knowledgeable people on this site. 
<br /><br />I decided to work on getting the head cover bolts loose yesterday. Out of 14, 13 came loose and one snapped . The 13 good bolts were all tightened back up after loosening. I don't have the new stat yet, and I've got a fishing comp on Sunday. If I use the engine on Sunday, is it likely that the head cover will leak water where the bolt snapped, and if so, will it harm my engine to run it for one day with a leaky head cover?<br /><br />Secondly, I can't get to the snapped stud with a drill so I've either got to try to tap it round with a punch, or use G Danes method of getting someone to weld a nut to the remains of the stud. G Dane says to use either TIG weld or MIG weld, I can't remember which one, but what is the difference between the two, and are they both safe to use?<br /><br />Thirdly, I read on here about using a Sierra thermostat as they are vented and self flushing, and do not stick. I also read that if you use an OMC stat, that you can vent them to prevent them from sticking. Can anyone tell me if Sierra stats are widely available, or describe the procedure for venting the OMC stats?<br /><br />Lastly, Will I have to replace the pressure relief valve too when I put the new stat in, and do I need to use a sealing compound on the head cover gasket?<br /><br />Sorry for all the questions at once, but I need all the help and advice I can get. <br /><br />Thanks in advance<br />Steve
<br /><br />I decided to work on getting the head cover bolts loose yesterday. Out of 14, 13 came loose and one snapped . The 13 good bolts were all tightened back up after loosening. I don't have the new stat yet, and I've got a fishing comp on Sunday. If I use the engine on Sunday, is it likely that the head cover will leak water where the bolt snapped, and if so, will it harm my engine to run it for one day with a leaky head cover?<br /><br />Secondly, I can't get to the snapped stud with a drill so I've either got to try to tap it round with a punch, or use G Danes method of getting someone to weld a nut to the remains of the stud. G Dane says to use either TIG weld or MIG weld, I can't remember which one, but what is the difference between the two, and are they both safe to use?<br /><br />Thirdly, I read on here about using a Sierra thermostat as they are vented and self flushing, and do not stick. I also read that if you use an OMC stat, that you can vent them to prevent them from sticking. Can anyone tell me if Sierra stats are widely available, or describe the procedure for venting the OMC stats?<br /><br />Lastly, Will I have to replace the pressure relief valve too when I put the new stat in, and do I need to use a sealing compound on the head cover gasket?<br /><br />Sorry for all the questions at once, but I need all the help and advice I can get. <br /><br />Thanks in advance<br />Steve