Crankcase Cover Leak

[DomsX20]

So, I rebuilt my 240 over the winter due to the infamous stripped oil gear. Everything went pretty well. Started in the driveway no problems. However, after it warmed up, I seen some very small bubbles forming on the crankcase cover. The bubbles covered an area about 1/2 inch. I also noticed that the Red Permatex 518 Gasket maker used to seal the crankcase was very wet like it never set up (I applied it 4 weeks ago). So my questions.

How bad is this?

Can I use some high temp RTV and try to seal the crankcase?

What would you do?

 

[koby6587]

So, I rebuilt my 240 over the winter due to the infamous stripped oil gear. Everything went pretty well. Started in the driveway no problems. However, after it warmed up, I seen some very small bubbles forming on the crankcase cover. The bubbles covered an area about 1/2 inch. I also noticed that the Red Permatex 518 Gasket maker used to seal the crankcase was very wet like it never set up (I applied it 4 weeks ago). So my questions.

How bad is this?

Can I use some high temp RTV and try to seal the crankcase?

What would you do?

i used the orange colored permatex high temp gasket on my crank case on my rebuild i have only burnt a half a tank so far buts its been good it stays plyable i usaully do hand tight wait a little ove a hour than crank it down

 

[koby6587]

Hey were you able to crank down any bolts or did you have to pull it the motor out to get it sealed up?

 

[DomsX20]

Just wanted to update the thread.... I took the boat out this weekend for about an hour. It ran pretty good but the crankcase was still bubbling and leaking where I could see. Did some research and found a leaking crankcase can cause the motor to run dangerously lean. I spent the winter rebuilding this motor so I figured I better pull the motor out and fix the leak.

Pulled the motor on Saturday. Tore the motor down to the point I could split the crankcase. Woke up on Sunday, resealed the crankcase, put the motor back together and reinstalling it in the boat.

Boy do I feel better...... Spent 2 days to make it right and I feel it was worth it.

The cause of the crankcase leak is the following. When I initially put the motor together, I used Permatex 51813 (Loctite 518 equivalent) as the manual calls out. I later found that I forgot a crankcase bearing so I cracked the crankcase, reinstalled the bearing but did NOT reseal the crankcase.... And I paid for it....

Lesson learned....

 

[bmat]

ok trying to look up old threads. But, do you advise replacing the worm gear b4 the bad stuff or just doing premix and shut it off and not idle. I am freaking out about the up coming season. Can I replace the worm b4 shit breaks with minimal problems?

 

[koby6587]

ok trying to look up old threads. But, do you advise replacing the worm gear b4 the bad stuff or just doing premix and shut it off and not idle. I am freaking out about the up coming season. Can I replace the worm b4 shit breaks with minimal problems?

You can but you are going to have to pull the motor out and strip it completely down to the crank where the gear is to replace it. There was a thread where they were going to try to take the pump off and slide the worm gear spindle from pump to plastic gear out. Than get a bore scope to check it out with im not sure if it would work but i think it would. I broke the brass tube that has an o-ring right beneath the pump on it that the spindle sits in and you should be able to take it apart so you have a dime size hole that you could stick a lit led bore scope about 3 inches down or so and see it and hand crank with plugs out to see it all the way around........ Just a suggestion have not done this myself.

 

[DomsX20]

I think it depends on the age and usage of your boat. My boat was at the end of its 8th season when it decided to lose its worm gear. With that said, the new worm gears appears to be much stronger but I have no idea when they started to incorporate it into the new motors. My opinion (for what its worth) is the motor is a 2-stroke, after 6-8 years (depending on use), it should be torn down and tuned up inlcuding hone the cylinders, replace the following: new bearings, gaskets, o-rings, seals, and worm gear. This will prevent ALOT of headaches.

Also, I am no mechanic but on my second try, it took only 4 hours to pull the motor and tear it down to the point where I could split the crankcase and replace the worm gear.