Yamaha dt 125r power valve

The Bajaj is a four stroke. If oil is leaking out of silencer you have a problem. Engine needs new rings, or oversize piston kit and rebore. Also fit new valve stem seals.

It is quite normal to have a small amount of oil in the airbox, however exsess oil in the airbox will find its way into the engine and burn hence smoke, remove the engine breather pipe from the engine to airbox and clean then replace, exsess crankcase pressure is caused by pressure leaking past the piston or rings, during detanation, dismantling of the top end of the engine is required for inspection, poss new piston and rebore.

The DT series had I believe a separate oil tank and oil injection pump.
Ensure the oil tank vent is clear, (some tanks have vent hose, others vented cap)...you need a vent to delivery oil to pump suction.
On the pump, ensure the stroke adjustment cable from the throttle is connected and rotates with throttle.

this is coolant being burnt check it if ok get back to me

buddy its not an easy job to do as if the barrel has been damaged that much it will have to rebored to an over size piston or a new sleeve installed or if its just a little scratch you can get some glass paper and run it around the barrel not stying in 1 place at the same time do this until smooth also you can take it to a shop and get them to rehone it for you or rebore it also when you put the new one in oil the rings and make sure the arrow is pointing towards the exhaust valve

Need more info...if you have a multimeter connect it to the battery while engine is running? Is it 1-2volts over battery voltage?

Oil in the air filter could mean tht the piston rings are weak thus throwing oil from the breather to the airfilter via the breather pipe.
Some filters do require a little oil like thK & N ones maybe in your bike it was over filled if at all.
You can run the engine with out the air fliter and see if theres smoke coming out of the breather pipe, if it does thn you will have to replace the piston rings or more over rebore the block and replace the piston kit.

Hope this helps !


Knight.YamahaSeca XJ750A 1981)