oil for 18 year old Tecumseh

[cdavidc1949]

I was given a Murray ride on lawnmower with a 12HP Tecumseh engine. The guy I got if from said it uses 30 weight non-detergent oil. I thought non-detergent oil went out in the 50's.Shouldn't it be 30 weight detergent oil? The dip stick does not say anything on it. The engine is 18 years old.

 

[-Clayton-]

I use rotella 15w40 in mine.

 

[Blue99]

The old school thinking was that non-detergent oil was best for an engine that did not have an oil filter. The theory was it was better to let the oil carry any contaminants back to the sump & have it settle out into the bottom of the oil pan.

Plus ND oils were typically used in lawnmowers due to the lower cost, people didn't want to use a quality motor oil.

I'd suggest getting a can of solvent cleaner, such as Seafoam, and a couple of quarts of cheap oil & run both thru the mower engine and drain after 5-10 minutes of run time to clean out some of the deposits generated by running ND motor oils.

 

[Chispas]

Blue, your explanation is correct....

It was around 1949 when Texaco Havoline,
I remember, introduced their new formula
with detergents....and other brands did
the same....

Pre-war vehicles like my folks' 1939
Ford had things like oil pump screens
clog from loosened sludge....

Lots of old timers still remember....

And, I don't blame them for not wanting to
switch, there could be sludge problems
galore....

 

[beanoil]

Any 30 weight will work fine. Walmart SuperTech straight 30 would be my choice, changed at the beginning, and half way through the mowing season.