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2003 Yamaha Big Bear 400, 4x4

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Old 02-25-2016, 09:26 PM
u09692's Avatar
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Default 2003 Yamaha Big Bear 400, 4x4

I noticed an oil spot underneath my Big Bear, about on the center line of the case. Upon closer inspection, I noticed where the two halves of the case come together was damp with oil. I also noticed that the rubber crankcase seal is starting to fray out of the case. The leak rate is about 1 to 2 drops a day when the engine is cold. It looks like replacing the seal would require taking the entire engine apart. Does anyone have good fix that doesn't required taking the entire engine apart?
 
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Old 02-28-2016, 10:42 AM
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Originally Posted by u09692
I noticed an oil spot underneath my Big Bear, about on the center line of the case. Upon closer inspection, I noticed where the two halves of the case come together was damp with oil. I also noticed that the rubber crankcase seal is starting to fray out of the case. The leak rate is about 1 to 2 drops a day when the engine is cold. It looks like replacing the seal would require taking the entire engine apart. Does anyone have good fix that doesn't required taking the entire engine apart?
Recommend you give the engine a good cleaning and then observe. It is normal for some of the "Yamabond" and other gaskets making products to "break off", peel and what you see peeling is usually excess sealer that doesn't perform any function. If it is fact leaking between the cases, there is no proper "fix" other than to split the cases and renew the gasket maker. Here's a link for a manual.....$5.
https://www.tradebit.com/G/manuals/14-atv
 
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Old 02-28-2016, 12:01 PM
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Since it's one or two drop a day you might get lucky and try to snug case bolts if you can get to them in the area that's leaking,but I wouldn't hold my breath on relying on that to totally solve it. It's a pain to have to tear into a good running engine to seal a small oil leak,I've had to do this also, but that may be the only way to solve it as Fasteratv mentioned. Either that or live with a leak and keep a check on it often.
 
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