Is a pre-filter a must? (Tecumseh OH195EP)
 

While having a carburetor rebuilt at a Tecumseh service center, I asked if they sold the air filters for the OH195EP engine. They only had the outer filter in stock but I was told that the pre-filter was not needed, unless the engine was used on grass cutting machinery. I explained the engine was for a go kart and used on dirt but he still insisted it wasn’t needed. He also said that pre-oiling the pre-filter wasn’t required either.

A pre-filter is only about $5.00 but isn’t it really not necessary like the tech said?

If you're in an area with fine dust, it's a good idea to have it on. oiling it i wouldn't worry about.

Pre-filter performance and required cleaning frequency will depend on water quality at the point of use. Pre-filters that visibly stain or collect debris can be a desirable indicator of water quality improvement for the end user (“If my pre-filter is dirty, it must be removing bad things from my drinking water.”). Where the source water is not turbid, the pre-filter staining may be the only indicator of water quality improvement outside of taste and/or smell.

This post is about "aircleaner pre-filters" for a TEC go kart engine!!!!

A prefilter is pretty cheap insurance to protect your motor investment. It only takes a few minutes of poor filtering to fry a set of rings. And oiling the prefilter is a must! A filter that you can wash and reuse is the most economical. I keep several extras, cleaned, oiled and ready to use in zip-lock bags and change them frequently.