redneckinker79

2000 Yamaha Big Bear 400 4x4 - Need Help ???

7 posts in this topic

i took off the pull starter and looked for the timing plug so i can adjust my vales and there is no spot like that what do i do its a semi auto 5spd full time 4x4 :confused:

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where do i look to find what year this quad is ??? maybe its not a 2000 idk im just lost with this thing

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ok i just checked my air box cover and it says engine family is YYMXX.387GCB AND NOT TO MENTION I FOUND SOME OIL IN THE BOX AS WELL IF ANYONE HAS ANY IDEAS PLEASE LET ME KNOW THANKS STILL CONFUSED

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you will find the vin usually on the frame by the motor on the left side (drivers door). you can decode it here :

Yamaha VIN Decoder @ Motoverse.com

a little oil is normal (no more than a couple teaspoons) if you have more, it usually means you overfilled with oil, you have a blocked crankcase vent line or a plugged exhaust. if your rings are bad, the pressure in the combustion chamber will create pressure in the crankcase and force oil up through the vent lines.

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yeah its about a couple of teaspoons so im figureing the rings are worn out as well but it def made a huge difference in performance im going to get a feeler gage today to set it right thanks again

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well i blew it up i guess changed the oil and then all it did was smoke like crazy lol rings and piston are shot after it stopped smoking ran great for two days and then just died so tore it down and looking to get a piston and ring set dealer has one for about $210

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