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Discussion Starter #1
Bought a 2004 Yamaha Big Bear 400 4x4 yesterday. It needs the bold holding the exhaust to the manifold. And need to replace the gasket for the timing chain cover, replace o rings, and fix the electric starter. Paid 1600 did I waste my money or is it worth the fix.
 

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Hmmm. I have a 2001 Big Bear. Whether it's worth fixing or not is entirely up to you. If you already spent
$1600 I sure hope it runs at least. Partzilla has all the parts for it. I'm not sure what you're talking about as far as
" timing chain cover". Minimum, I'd check valve clearances, change the oil in the motor and both differentials,
bleed the brakes and inspect the external shift linkage, inspect CV joints and boots. Mine sat in the snow
for 10 years before I bought it, running strong now.

Mad
 

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Discussion Starter #3
It sounds great it's the oil leak and smoking I'm worried about. Besides the electric start. I ordered the new bolt from partzilla.
 

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Is the smoke coming from the exhaust or from oil dripping on something ?
If it's from the exhaust, there are a few possible reasons.
Too much oil
Valve guide seals
Worn rings.
A leakdown test can really help you pinpoint the problem.

Mad
 

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Didn't really answer the question. If it's smoking because oil is leaking onto the hot parts of the engine,
then of course replace the gaskets or seal it up. If the smoke is coming out of the exhaust it points to an internal engine problem. Check this
Have someone ride it in front of you. Have them accelerate hard. Watch for when you see the most
smoke. If it smokes on acceleration, it's usually worn or broken rings.
If it smokes on deceleration, it's probably valve guide seals.
The better way is to do a Leak down test.

Mad
 

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Discussion Starter #7
My bad I thought I answered your question. It has a leak on the hot parts of the engine and exhaust.
 

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Ok. I guess just figure out where the leaks are. Pro tip....get some spray on Foot Powder. Clean the engine, let it dry
and spray the powder where you suspect a Leak. Start the motor. Any oil leaking will immediately show up as
a brown stain. Saves a lot of time.

Mad
 
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