Hole in Crankcase Cover
Posted November 17, 2002 - 08:22 PM
Don't know if anyone has experienced this problem; A rock punched a hole in my crankcase cover during an Enduro this past Saturday. The hole is located just forward of the straight plug. I was 45 miles into the 75 mile enduro when I discovered oil on my boots and left side of the bike. It was still running and oil loss was minimal. I figured on running it 'til it died or I finished the race. My bike ran great for 25 hard miles before it finally quit on a long uphill. It did not seize, the oil level was still adequate, it just stalled. Tried every method and trick to start it for an hour, but not even a pop. Finally, after a PBJ sandwich break, I gave the throttle 3 twists and it started for about 2 seconds. There was oil mist and forced air coming out of the hole. Long story short is that I was able to keep it running by constantly pumping the throttle to keep gas feeding the cylinder and got out. My questions are: 1. Any thoughts on why it would die after that many miles. 2. Is there normally pressure in the crankase to blow air and oil through a hole in the crankcase cover. 3. Anyone think of other problems that may result from the punched cover?
Thanx for your answers and the awesome forum!
Posted November 17, 2002 - 09:25 PM
Posted November 18, 2002 - 06:05 AM
BTW, where is the "straight plug"?
Posted November 18, 2002 - 09:57 AM
Posted November 18, 2002 - 10:44 AM
So I guess it was sucking and blowing all the dirt in and oil out for 45 miles or so. That can't be good.
Anyway, I guess if the hole was small and there was still a 1/2 Qt or so of oil in the motor after you stopped, Yr motor could be okay. The fact that the bike won't restart is not a good sign though. Low oil level sometimes results in the clutch going south before the motor seizes
At this point I'd:
Change the oil (whatever is left)
Pop a new plug in.
Cover the hole with some epoxy.
Try to start it and see what happens.
If the motor is lunched, running it a little more won't matter, after what you did to it already.
Posted November 18, 2002 - 02:53 PM
Also the crank case is under pressure and can suck in stuff, as evidenced by Yamahas excellent routing of the crank breather tube just under the shift lever, many a rider has ridden thru deep water or stalled and restarted the bike in water only to suck water into the engine.
I was unclear if the hole was from a rock or if you lost a plug. Either way I would measure how much oil is left and make a determination from there whether to flush it out really good with oil, strain it to check for debris, or tear into it to check for engine damage. JB weld can make it all better.
Posted November 18, 2002 - 03:20 PM
I did just as you suggested today. Plugged the hole (more like a 1/2" tear) with JB weld and drained the oil. I lost < 1/2 a quart and the oil looked good; no water, dirt, metal, etc. Changed the filter while I was at it. I'm going to let the JB weld set up for ~ 24hrs to ensure a good bond. I've got my fingers crossed until tomorrows trial run. Thanx to everyone for your help and input.
Posted November 18, 2002 - 07:26 PM