water on the plugs

[sadam68]

i have a 1984 johnson 70 hp. had a problem last weekend with the boat losing almost all power,very low rpm's. i forgot to put the oil in the gas and it ran for about 5- 10 minutes this way and i realized what i did but obviosly too late!! i pulled the plugs today to see if they were fouled and found water on the lower 2 plugs, the top was fine. just wondering how bad this really may be? maybe a gasket or probably a cracked cylinder. just want to know if my season is over before it starts. thanks, scott

 

[JB]

Re: water on the plugs

If you are lucky it simply blew the head gasket, sadam.<br /><br />Less lucky is a warped head and blown gasket.<br /><br />Least lucky is a terminal engine.<br /><br />Do a compression test, and good luck.

 

[sadam68]

Re: water on the plugs

JB or anyone else,<br /> i just checked the compression and I have 100 on the top and bottom cylinders and 50 at the mid cylinder. i bought a head gasket today and will make an attempt to replace tommorrow. any info that anyone can pass along would be great!! thanx, scott

 

[sadam68]

Re: water on the plugs

JB or anyone else,<br /> i just checked the compression and I have 100 on the top and bottom cylinders and 50 at the mid cylinder. i bought a head gasket today and will make an attempt to replace tommorrow. any info that anyone can pass along would be great!! thanx, scott

 

[Stumpys]

Re: water on the plugs

Wow, I think 50 is way too low on that one cyclinder. I think the pro's here will get ya on the right track.

 

[Ranger01]

Re: water on the plugs

I'm not an expert like JB, but i do know that if you have 100 in two cylinders and only 50 in another then i'm almost posative that what you have there is an anchor. From what i understand about compression tests, there should be at least 100 in all cylinders and not more that 5-10 lbs difference between them. I would wait for JB's answer first but i dont think that 50 is a good sign for your season my friend. do your compression test again to be positive, could hurt. Good luck.

 

[R.Johnson]

Re: water on the plugs

When you ran the engine with no oil, was this at WOT? Did you run the engine until it started to slow down on it's own. When you pull the cylinder head, take a look at the cylinder walls on that center clyinder. The problem here is, that runing the engine with no oil, it could, or would have an effect on every moving part. You are probably looking at a full tear down here. Let us know what that center cylinder look's like.

 

[scotta68]

Re: water on the plugs

i put a new head gasket on yesterday and found that the old one was rotten between the 2 lower cylinders with no other apparent damage. when the boat lost power i was not at wot, no tach but we were only running slow as i had just switched tanks and it takes a little bit for the boat to get up to speed as it is very under powered for the size of the boat, just my feelings. i checked the compression and they were all at around 70 lbs. the boat runs good now but there is a definite loss of power now. i took it out after i was done and only 20 mph vs. 28 before. now i'm stumped, i had better compression on the bottom and top with the bad gasket. any ideas? i want to get a bigger motor (used 100 hp) but would like to try to fix this if possible. any thoughts please!!!

 

[Solittle]

Re: water on the plugs

What did the walls of the cylinders and the pistons look like with the head off?<br /><br />I suggest that you recheck the compression with a different guage and post the results. If the readings still are around 70 you are looking at a complete rebuild.

 

[scotta68]

Re: water on the plugs

went back down today to make sure i had spark at all cylinders and found water again but on the top 2 this time. i re-checked the compression and had 83 on top and 95 on the mid and lower. the boat still runs and starts with no problem. i am going to take it apart again and do it again. what is the torque supposed to be on these heads... 1984 70 hp johnson. i torqued them at 18 ft lbs as what i saw on the site some where and in a spiral pattern from the center as this is what i was told when i picked up my gasket. is there anything more i should be doing or looking for as i am doing this. thanks so much for all the input so far, hopefully i'm getting there as i am not going to dump a lot of money into this... i want a bigger one!!

 

[R.Johnson]

Re: water on the plugs

You are grooming a dead horse!

 

[sprouticus]

Re: water on the plugs

Originally posted by R.Johnson:<br /> When you ran the engine with no oil, was this at WOT? Did you run the engine until it started to slow down on it's own. When you pull the cylinder head, take a look at the cylinder walls on that center clyinder. The problem here is, that runing the engine with no oil, it could, or would have an effect on every moving part. You are probably looking at a full tear down here. Let us know what that center cylinder look's like.

I recently did the same thing with my 1977 70 hp (another thread) What does it mean that the engine started to slow down on its own?????? I am scared now

 

[R.Johnson]

Re: water on the plugs

The pistons get hot enough that they expand to the point that they are to tight in the cylinder bore. This will result in scuffing of the piston, and it will deposit the torn metal to the cylinder wall, Without oil, other moving parts are also damaged.

 

[sprouticus]

Re: water on the plugs

the enigine didn't seem to be overly hot.......but it definit;y acted weird. sigh.I guess I learned something

 

[scotta68]

Re: water on the plugs

i would just like to thank everyone that has anything to do with this site. with advice on resurfacing the head i have found elsewhere on this site, i was able to successfully get the motor back to it's previous state and will now continue to enjoy my summer. thanks again, scott