Yamaha TTR110 Crankcase Vent Quick Fix

The Issue: The stock TTR110 routes the crankcase breather line into the air filter causing the airbox to be filled partially with oil when the bike is tipped over. If this happens enough the bike will fail to run. Other bikes, such as the Kawasaki KLX110, and/or the Suzuki DRZ110 do not have this issue since the breather line is simply routed up and then down under the bike without a filter where the oil drains onto the ground if you take a spill. More than likely, the newer Yamaha bikes route the line into the airbox to be more environmentally friendly. Unfortunately, The oil usually ends up spilling on the ground anyways because you have to take it apart to remove the oil during your ride to fix the problem.

The Fix: Buy a crankcase filter from the auto parts store, preferably one with an inlet and an outlet such as the one shown with a filter inside. The one I found works great, but the outlet size is too big. A better fix would be to get a reducer to use smaller hose on the outlet and make routing it easier, but other than the bulky look, it works awesome and I did it for three bucks and a piece of old power steering hose.


The plug is a vacuum plug, but a piece of hose with a bolt in the end or something would work too. If you don't have a vacuum plug though, just go buy one because the hose would just be lame and probably rattle around, possibly cracking the airbox.

Below is the outlet hose(from the new crankcase filter) routed down the other side of the bike. There is more room over here to route it and it doesn't cause any interference at all. The big hose stays for now, but a reducer with a smaller hose similar to the inlet size would look better. If the hose is routed high enough, the amount of oil that might escape is greatly minimized. With the way this breather filter is designed, most of the oil will probably just drain back into the crankcase without getting contaminated.