Kohler oil question

This spring I bought a mower with a 16 horse flat head Kohler (Magnum). I don't know the exact model - it is tucked so far down I there I can't see anything (a Deines zero turn). It has electronic ignition so I know it isn't a dinosaur, but that's about it.

It runs well and never blows smoke of any kind under any condition. It doesn't leak and the exhaust is clean. It is using oil, though. It is down to the add line about every 6-8 hours. The previous owner said he never needed to add oil but I don't know what he used. I've never seen an engine keep the oil this clean. It is a replacement so I don't believe it has many hours on it. I know it was in there for the three years that the guy owned it.

I have always used straight 30 weight in anything smaller than a car or tractor. Is there a better option for this engine? I always thought I heard that they will use oil if you use multi-vis in them. Is that true? I don't believe it is wear, so I am wondering about the oil.

We all have are opinions on what oil to use, and just mentioning "OIL" has started countless arguments on here, so instead of telling you I have quite a few small air-cooled engines that have thrived happily for YEARS on Mobil 1 10-30, I will instead post links to the factory Kohler owner's and parts manuals and you can see what Kohler recommended when they were new.

(ASSUMING from what you posted it is a 16HP single-cylinder Magnum.)


Parts:
http://www.kohlerengines.com/onlinecatalog/pdf/tp_2203_a.pdf

Owner's
http://www.kohlerengines.com/onlinecatalog/pdf/tp_2200_f.pdf

Kohler....the very people that designed and manufactured this engine... are quite adamant that straight grade 30 weight detergent based motor oil be used in all Kohler K and M Series engines when the ambient temps are above 32 F.


Using multi-grade oils promotes increased oil consumption, as you already understand.


High oil consumption comes down to one or more of these problem.

1. oil is leaking out of the engine oil pan/block assembly.

2. oil is being burnt in the combustion chamber due to worn rings, worn valve guides or both.

3. oil is being forced out due to a problem with the crankcase ventilation system.


Oil being burnt as part of the combustion process should be easy to detect in the form of a bluish tinge to the exhaust smoke.

The other two problems should show up as oil dripping on the ground when the machine is parked for awhile.

There is obviously a problem that needs to be diagnosed and corrected because if the oil level gets too low, then you will break the rod. There is no alternative oil that will correct any of these problems. A Leak Down Test is in order if there are no visible signs of oil loss.

I have several Cub Cadets with the K engine. When they start to use oil [burn oil because of ring wear] I switch to straight 40 oil and add a little lucas oil treatment with it. This is only a temporary fix, until I get time to overhaul them.

One other test that may uncover the problem is the crankcase vacum test. It involves using either a manometer or a vacum gauge (H20) to check the amount of crankcase vacum the engine can produce. That and a leakdown should tell the story.

I am thinking 8" vacum is minimum for a M16, but I don"t have my manual handy. You can find out for sure on Kohlerplus.com.

One other thing that Kohler is telling us about the oil used in their newer engines. They like small engine oil because it still has zinc in it.
Both Kohler and Kawasaki say their brand oil still has zinc in it.

Shell Rotella T1 straight grade oils still contain all the zinc that they had before the change in specification.

Shell's Triple Protection multigrade Rotella line also has plenty of zinc in it; far more than most oils formulated for gasoline engines but using a multi-grade oil in temps above freezing is not recommended by Kohler.

Now if you want to spend more money because it makes you feel good to do so, then you can run the Amsoil product that is labelled as being suitable for running in small air cooled engines or choose oils labelled by Kawasaki or Kohler and pay a premium price also.

The Kohler K and M Series engines are both splash-lubed and have no oil filtration. Therefore, it is essential to drop the oil every 25 hours of operation MAX to get rid of the contamination. If you are really concerned about extending the life of your K or M Series engine, then change the oil every 15 hours.

What matters most to these engines is CLEAN OIL, not fancy, shmancy expensive oils that promise long oil life. Whether you spend 3 bucks a quart or 30 bucks a quart, ALL oil will become contaminated at the same rate and without an oil filter, changing the oil frequently is the only protection against rapid wear.

The first Cub Cadet I bought had a K321 that burned about 1/3 of a quart (or more) with every tank of fuel. You did not add gas without adding oil. The only blue smoke it blew was on start up - usually one big puff and then it ran clean and it had pretty good power.

All it needed was an overhaul, the top of the piston was worn a surprising amount and I was told by a knowledgeable person that it was caused by dirt from either running without an air filter or a leaking filter housing. The rings were also in poor shape but none were broken.

It will run a long time burning oil but all it takes is forgetting to add it one time and you'll have some serious issues.

I can't see any problem in using a good multigrade oil.I have been using Shell Rotella T 15-40 for over 35 years and and no problems. Run it in B&S and Kohler air cooled engines and change oil by hour meter hours.My oldest garden tractor is 27 years old and is coming up on 2000 hours and never been wrenched and run on Rotella T 15-40 from day one.

There is nothing detrimental about using the Rotella 15W40 because it will behave like a 40 weight oil when the engine is at operating temperature. Rotella or DELO are the two best choices because both are designed for use in diesel engines.

The Kohler K/M Series engines along with several other L-head cast iron engines from the 50's, 60's, 70's and 80's were DESIGNED to burn small quantities of oil during normal operation. The key issue here is that of OIL LEVEL because it is critical to keeping the crank throw and main bearings heavily lubricated at all times.

Therefore, if you want to use a multi-grade oil, then you must keep a much closer eye on the dipstick level and keep the crankcase topped up at all times. If you forget to do so, then it only takes a few minutes while mowing a ditch or hill on the cross-slope to cause an oil starvation situation and the loud bang you hear will be the con-rod snapping in two.

Kohler themselves WARN owners about increased oil consumption when using multi-grade oils when the ambient temps are warmer than 32F. Very few owners have hour meters installed on their tractors and they end up guessing when it is time to change the oil. With no oil filter, it is essential to the life of the engine to change the oil every 25 hours MAX or sooner if the conditions are more severe than normal.

Oil is cheap compared to the cost of rebuilding at changing it takes a lot less time than rebuilding does.

Tom I am not trying to dispute what your saying. But I have two of my Craftsman Garden tractors that are powered with Kohler ( 22 hp with 500 hours and a 25 hp with around 800 hours)and these engines never use a drop between oil changes. The Garden tractor in picture is Briggs & Stratton powered with the two cylinder opposed which was known not to be a high hour engine but this one is getting close to the 2000 hour mark. All my garden do run on Shell Rotella T 15-40. I don't use my tractors in winter so in the fall I clean,repair and pickel them for the winter.

Your Craftsman is powered by V-twin Kohler with OHV and a pressurized, fully filtered lubrication system. You cannot compare one of those engines to the L-head Kohler K and M Series engines on the issue of oil consumption. The modern OHV twins have much tighter tolerances in their design and manufacture.

Therefore, I do not dispute what you report about that engine. But this is an apple to oranges situation and unfortunately, so many of these discussions end up that way. One person cites their personal experience with their OPE but they do not take into consideration the technology differences.

Fords, Chevs and Dodges built in the 50's and 60's came with engines that routinely burnt about 1 quart of oil every 1000 miles or so. As someone who worked in Service Stations back then, it was routine for me to pop the hood and check the oil on every car that pulled up to the pumps for gas.. Those days are gone. Better metallurgy, better design, tighter tolerances etc all provide engines today that don't consume a pint of oil in 5000 miles or more

I cannot comment on your Briggs engine because I am not familiar with them.