I have the 330 kit fitted on a 2018 klx250s. The manual states 1.1L with oil filter.

Various mechanics insist I add more, but one guy is insisting I stick to 1.1L to avoid starter gear damage.

How much is everyone adding with big bore kits or is it best to just go halfway in the sightglass?

 

No additionally oil needed. All based on sight glass

 

I would quit listening to any "mechanics" that tell you a big bore takes more oil. They aren't right and they are clearly missing some mechanical knowledge. Crank case size and oil sump size (aka oil pans) dictate how much oil will be needed. the crank case didn't change, so oil level didn't either.

 

Precisely why I am here. Living in Vietnam, it is a challenge. Most mechanics are self taught and able to fix your bike good enough to get you to the next mechanic. Thanks for helping me understand a little more.

 

Makes sense, glad if we can help. Keep using the forum and also you can find a shop manual that should work for most of your needs. The 2018 is pretty much the same as all the earlier years. I do have a few manuals in files and could send a zipped copy if you can't find one online.