I HAVE A 1993 BIG BEAR 350 4X4 THAT HAS JUST STARTED SMOKING AFTER START UPS.

I HAD YAMAHA ATV OIL IN IT BUT CHANGED TO VALVOLINE 10 W 40 ATV OIL.
A WEEK LATER IS WHEN THE SMOKING STARTED AND GOING THROUGH SOME OIL WHILE RIDING -HALF A QUART TO 35 MILES OF NORMAL TRAIL RIDING.

DID CHANGING OIL @ BRANDS CAUSE THIS OR MAYBE OTHER PROBLEMS.

 

The valvoline shouldn't be the problem if it's made for atv's, i had a 86'Honda TRX350 4x4 (my first atv) i changed it to Castrol GTX 20w50 at the first oil change and never had a problem ; didn't use a drop between oil changes ! And on my second atv a 93' Suzuki LTF4WD KQ 300 i used the same oil in it with the same result's , i sold the Honda in sept 05' to my brother ; and in jan 06' i bought a 2006 Arctic Cat 400 FIS auto with the Suzuki powered Duramatic system and i changed the oil to Castrol 20w50 with great result's again ! I sold the KQ to my brother a week after i got the new Cat , and he and his wife are still riding the Honda and Suzuki everyday ; so as long as you use an oil that work's with wet sump system's i don't think that would be your problem ! williebee