Water in Cylinders

1986 90hp 2 stroke. I pulled the plugs yesterday and there were water drops on the two from the top 2 cylinders. #3 looked good. While running on the water the day before it started to cut out at full throttle. Any ideas on what I should check first before I pull the head off?

[mokaction]

check and replace head gasket. Also check Stats, impeller!! Reason is that you want to know why the head gasket failed. Usually do to over heating..

Larry

will i be able to tell if it was the head gasket that failed?

[jb123]

USUALLY you an see where there was blowby.

Stupid question, but are you sure it was water, or could it have been gasoline? Did you smell it to see? If it's gasoline your 2 cylinders could be getting incorrect spark, or no spark at all, and fouling out the plugs and cutting out.

No I’m not sure it was water. Gonna take a look at it tonite. The #3 plug is on a < 2 year old coil. The 2 bad plugs are on original coils. Reason being that the engine overheated and blew up a piston. Piston was replaced, cylinders were honed, all rings gaskets and thermostat replaced, head and block checked for flatness. Rebuilt engine ran, but rough. Determined that #3 coil was bad, and replaced, and that solved the problem. So my questions now would be: would the stress that caused the #3 coil to go bad take almost 2 years to effect #1 and 2, and is it likely they would go at the same time. Also, it doesn’t seem to have any problems at idle, just at full throttle….is that on par with a bad spark? Thanks for the idea, I’ll check spark tonite too.

Your other coils should be fine. In my experience it takes many years or a lot of corrosion to kill those. Just smell the plugs and see what they smell like. Also check to see how clean the wet plugs are. If they are real clean, it's probably water. Too much gas will also tend to clean them off, but not as much.

It may be a bad spark, but it could also be that the carburetors are giving those 2 cylinders too much gas, but you can just adjust them to fix this unless there's something else wrong. If it's spark, then I would try replacing the plugs first. Sometimes those things foul out real easy and just won't burn. It could also be the plug wire if they are older. I had an Evinrude one time that was running bad at mid RPM because of a bad plug wire. I replaced that and it was just like new again.

On a side note, I don't know about yours but my 40hp 2 stroke has the coil and plug wire altogether where you would have to replace the entire thing. Unfortunately you can't just buy the plug wire (if that was the problem)...

Mine is the same.

The 2 bad plugs where black and oily looking.

How do I test carbs…..lean them out while at higher RPM?

[mokaction]

a good way to tell it is water. is the spark plug will look like it is new, also if you look in the spark plug hole you should see the piston, and the piston will looked washed. cause the steam from the warm or hot motor will steam clean the piston clean as new. If it unburn gas, the plug my look brown like it was burning flooded. Or over oiled.

Larry

[mokaction]

you can do a leak down test if you have a leakdown tester, if not try doing a compression test first. that will tell you if you have a leak some where.

Larry

just did some testing. checked head and head cover torgue. all good. pulled plugs again. every plug had BLACK oil/gas around its base. cleaned em and put em back. also cleaned the fuel filter. during warm up, for about 10 minutes, i had it at idle half the time and a fast idle the other half. it ran great. after about 10 minutes i ran it up a little higher, maybe 3/4 throttle, for a few seconds, dropped it back to half throttle for a few more, and then back to idle. then, at idle, it started acting like it was missing. it would chug slightly a couple of times and die. restarted and brought it back to fast idle and it would chug a couple times and then die. pulled the plugs again, and they looked good. no droplets on them and the 2 that were on the bad cylinders before seemed a little cleaner. put everything back, but the #1 plug and started it back up at faster idle to keep it running, couldnt see a spark so i put my hand behind it, and a big blue spark jumped about an inch to my finger, but it didnt feel that strong. #2 i could see a good spark. #3 i didnt check cause its on the new coil. put all plugs back, got it running at faster idle, and started pulling wires. pulled #1 and it was slightly noticable, and i didnt feel a shock thru the rag i was using to grab the wires. #2 was much more noticable when i pulled it, and it shocked me good thru the rag. #3 was noticable and slightly shocked me thru the rag.


new coil for #1??? how come there didnt seem to be a problem at first, during warm up?

[mokaction]

did you already replace the gasket?? Also do a spark test. Do you have a air gap spark tester? Also how are the fuel filters?

larry

the head gasket? no. gonna wait on a compression test. after running tonite there wasant any liquid on the plugs tho.

fuel filter is old. i have a new one on the way, but i took out the old one and cleaned it off b4 running tonite. dont have an air gap spark tester. not sure what that is. looked on line and couldnt find it. can i do a spark test without it? how bout switching up coils?

[mokaction]

do you have a manuel?? Also do you keep the boat in the water???

i dont have a manual. have been looking for an owners manual for a while, but cant find one for my year. dont have a clymers either tho.

keep it in my garage.