Servicing Kohler OHV Air Cleaners

[richters2]

Just got finished using my Sovereign under VERY dusty conditions. I serviced the air cleaner once every hour. This is my first experience with a Kohler OHV Twin, and I thought I’d share a few tips. 1) Before you do anything, close the choke tight. 2) Gently blow off the entire engine with compressed air. 3) After removing the plastic air filter cover, gently blow off the filter. 4) Blow out the 4 cooling air ducts. 5) Remove the filter. 6) Cover the choke area and either blow off the filter base, or use a vacuum. 7) Before reinstalling the serviced or replaced filter, double check to make sure nothing has fallen onto the choke plate. Not near as easy as the old K series or B&S flatheads, but that’s the design….. What can I say?

[Roy]

The 18 hp Kohler OHC twins are as bad or worse. I'm extremely disappointed with the air filter design and shocked that Kohler and Simplicity would market such a poor device. I only clean the air filter on my B-1 B & S Model 19 around once a year. Now that's a good design!! Roy

[Al]

Hi, One of the problems with these newer generation engines is that to make the emission specs and be able to build engines, a couple of things had to happen. One the engines run a VERY lean mixture. Two they run some very high cylinder head temperatures due to the lean mixtures. When you add the fact that most applications now the engines are enclosed and gas is Crap, an old problem from the 40s and 50s arises. Vapor Lock. Part of the temp testing in our Re-power kits involves constantly measuring temperatures in the venturi of the carb while running under full load in a 110 degree room for an hour. Then doing a hot restart test after shut-down. Smoe of these parameters get pretty tough to meet. Keep in mind that when these engines are designed, they may be used in equipment at the equator. One of the solutions to these problems is to use the cooling fan to bring cool air to the carb. One of the drawbacks is that it also brings trash that could make it through the cooling fins, but not through the air cleaner. Problem is more complex than it looks on the surface. In the future particularly on small 2 cycles look for sealed non-serviceable carbs in order to make the 300 hour use EPA requirements. Over the next 4 or 5 years these requirements are going to get significantly tougher to make. Good luck, Al