The 1966 briggs update stated the engines (of that time frame) were tested to 1000 hours. All required maintenance was performed.

I see many of the V twins that are about 10 - 13 years old. The engines (and the mowers) are tired. Hour meters frequently indicate 250 - 300 hours of service. Upon examination, I usually find dirt in the intake, contaminated air filters, and very low oil quantity. There is usually an accumulation of dirt around the oil fill tubes and valve cover gasket areas.

Many of these have intake push rods that have fallen out of position. During further analysis, valves are frequently found stuck in the valve guides with residue from the ethanol fuel.

Generally, repair cost exceeds the value of the equipment.

Per my calculations, 1000 hours on and engine would be about 25 years of use.

Life: 1000 hr

hour/mow: 2 hr

Mow/season: 20 April 1st to Oct 1st

That works out to 25 season or years.

Is that correct?

If so that is more meaningful than 1000 hr.

***"The 1966 briggs update stated the engines (of that time frame) were tested to 1000 hours."***
But, to accumulate 1,000 hours of use (in a short enough real time) in "laboratory tests" requires that the engines be run nearly continuously.
Continuous running for extremely long periods of time DOES NOT produce the same results as actual usage in a real world.
An aspect of engine wear that is seldom even considered is the "Operation Cycle", or "drive cycle".
An Operation Cycle is a single event where the engine is started cold, and then operated for a period of use during which it warms up completely to normal temperature, then shut off and allowed to cool down completely. The typical OPE engine will sit parked for about a week between drive cycles.
Because the most wear occurs during a cold start up, the more cold starts an engine has in its "life time", the more wear could be expected to accumulate.
And this is presuming no harmful conditions exist, such as vacuum leaks (which let in unfiltered air and also cause lean burn) or low oil circumstances.
When laboratory tests are done using continuous run methods, the cold starts are effectively removed from the equation, so the expression "your results may vary" certainly applies to this.
***"Life: 1000 hr

hour/mow: 2 hr

Mow/season: 20 April 1st to Oct 1st

That works out to 25 season or years.

Is that correct?"***

Huh?
April 1 to Oct. 1 is 26 weeks @ 2 hrs per week = 52 hrs per year.
1,000 hours divided by 52 = 19.2 years.
This points out that math deals with VARIABLES, and just seeing the purported solution of someone's equation is not conclusive unless one states all the variables used to arrive at the solution.
So, what variables were used to yield a solution of 25 years at 2 hrs per week?

I made an assumption.
While indeed it is 26 weeks in the period specified, Most lawns will not need mowed every 2 weeks between April 1 to Oct. 1, so I use 20 In fact some people may be able to mow their yards year around an others may not be able to mow 10 times during the growing season.

Some people may be able to mow in less than 2 hours, others more. Some people may use their tractors for jobs other than mowing. like pulling a trailer for landscaping jobs or pulling grandchildren around the yard in the trailer..

It was just an attempt to see the life time in years which are more meaningful than hours.

My tractor has lived in northern and central Indiana and now in Easter Carolina. Knowing the tractor is only 10 years old means that with good care it will last many more years.

I almost wish my 17 yr old 14hp Briggs V-twin would blow up! That would FORCE me to replace my Broadmoor with something that has a bigger deck!

Good points here, Maintance including the blades, operator abuse, oil type, operating in hot weather, manufacturing tolerances, all add up to the life of an engine. Sorry I don't buy the one about cycles. Could be a factor, but there are way too many factors that are more important.

Sorry I couldn't sell you a cycle. Maybe you can buy a car that was owned by a little old lady who just drove it to church on Sunday.

I have one with about 260 hours accumulated in about 4 years and it runs like new. Another about 12 years old, unknown hours-- but quite a lot. It uses a bit of oil now, but that may be from leaking as much as burning. Still produces good power with brief smoke only at cold startup.

2003 B&S V-twin 20hp Intek has 400+ hrs still running strong.
I change the oil once a year. Clean air filter maybe 2-3 times a year and adjust rockers when they get noisy.

Even ran it for a season with no muffler just because I missed my Harley!

This post was edited by corn_squeezer on Sun, Aug 11, 13 at 15:26