My 2015-1/2 KTM 250SXF Factory Edition has an oil leak. Strangely, it is on the ignition cover. I’ve checked every thing and there is no crack, hole or leaking gasket, but there is always oil on the back of the ignition cover just in front of the shift lever. Is there a problem with the gasket? Can you help me?
When KTM machined the oil ports into the ignition cover they had to make the internal oil line make a 90-degree bend. To achieve this they drilled the first half of the oil line from straight down and then, to make the oil go towards the front of the bike, they drilled a horizontal hole that intersects the vertical hole to make the oil bend at 90-degrees. This is common practice, since you can’t drill a curved hole. To seal the intersection where the vertical and horizontal oil lines meet, the horizontal hole is threaded and a 3mm Allen bolt plugs up the extraneous horizontal drill bit entry point.
On your bike the oil is leaking around the 3mm threaded plug. It is a very small leak and is often mistaken for an ignition cover gasket leak. (see photo above). Since the oil galley is fed by the oil pump it is under enough pressure to make a mess on the cover. It looks worse than it is, but it won’t leak enough oil to cause any engine problems.
The solution is to remove the 3mm Allen plug, clean it and put medium Loc-Tite or silicone sealant on the threads and then put the plug back into the hole.
Once you have cleaned and replaced the Allen plug, dab some high-temp silicon over the top of the plug hole as a fail safe.