Oil gas mix for a 2005 yz125 - 2005 Yamaha yZ 125

The premix settings are incorrect, the engine is receiving too much oil in the mixture. You could try a de-coke of the silencer. just remove and clean the baffle. This is only a stop gap until you get the oil/fuel mix correct.

oil doesnt mix with gas on a 4 stroke motor--u have a dry sump or independent oiler for the crankcase-cap may be stripped cud use a rubber gripper onit--use the lubricant a dealer tech sez

call dealership and ask to speak to a tech-he can look it up for u --chec fuel delivery from tank to float bowl etc

Use TWO STROKE ENGINE OIL in the pump. If not using an automatic oil pump, then mix the gas and oil 32 to 1. That equals 4 ounces of TWO STROKE ENGINE OIL to one gallon of gas. NEVER use motor oil in the gas. Only two stroke engine oil.

yeah something you wanna check next, compression. if you can get your hands on a compression tester.

this will depend on what gas oil mixture you have

check this topic out.

http://www.dirtrider.net/forums3/showthread.php?threadid=117838

http://forums.dirtrider.com/70/7640379/yamaha-dirt-bikes/yz125-carb-settings/index.html

regards,

voodoo