Lawnmower confusion

Oct 07, 2009 19 Replies

I have a 6.75hp Craftsman lawnmower with a Techumsa engine and my son has a



4.5hp Craftsman lawnmower with a Briggs and Stratton engine. I just cut my son's very tall, thick lawn (3 weeks of rainy weather) with his 4.5hp mower and it never bogged down to the point of stalling and rarely slowed down much, even taking full width cuts. OTOH, my 6.75hp mower bogs down on thin, long lawn (2 weeks little rain) to the point of totally dying if I take any more than a 1/4 width cut. What gives?

Mike D.


Which is why people who are in the know avoid Tecumseh engines like the plague. That and the fact that after a couple of years they usually refuse to run at all & even a good mechanic is hard pressed to change that.

Sharp blade?

I recently discovered a better way to really shorten the grass without loading up the mower. I try to mow shorter during the non-summer months (Supposedly reduces fungus problems). Mowing with the mower set as low as I want results in it frequently loading down. I tried mowing with the front wheels set to the lowest position, and the rear wheels on the highest setting. This seems to enable the Snapper mower to cut cleanly, and allows more airflow which carries the grass out to the bag better. I didn't have any stalling problem using it this way.

That's complete and udder ( :) ) bull-hockey.

I've a nearly 40-yr old JD 112 w/ the 8-hp Tecumseh that still runs just fine, thank you very much. It does have a new carb as after all those years the throttle valve arm wore so that it had enough air leakage to cause surging and make keeping mixture was difficult.

The 8-hp is plenty for the 38" 3-blade deck.

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I'd guess needs sharpening for starters and mixture is likely off so isn't running well. Governor may be stuck so isn't opening under load properly is another possibility.

It ain't a failure of Tecumseh engines; there's something not right.

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On Oct 7, 3:42=EF=BF=BDpm, Michael Dobony wrote= :

As you can see, there are many possible reasons.

Some more: Type of grass is another, thickness of the grass, moisture content, height, Self-propelled vs non-self propelled, how the HP is rated. I am not sure, but some MAY measure with blade on, other may measure with blade off. Short stroke HP vs a motor with a longer stroke, weight of flywheel and I am sure there are other factors.

Hank

Horsepower is not torque. Your 6.75 has less torque.

Sharpness of Blade difference?...Size of blade difference? Design of blade difference? Depth of cut setting? Design of mower deck difference? I'd check those out first before I started... I had a very expensive Huskvarna (HAD) and it had a larger Briggs & Statton motor than my father in-laws Sears Briggs & Stratton...I couldn't even think of keeping up with the father in laws machine... Both garden tractors with the same cutting width...I really think design has a lot to do with it...That Sears tractor could not only out cut, but could bag leaves in the spring clean up way better than that damned Huskvarna....again the Huskvarna had a larger Briggs engine by I think 3-5 HP more...so yup...my take is design and blades...........Jim

When was the air filter last replaced?

Water in the gas. Throttle problems. Burnt valve. Weak spark plug. Low octane gasoline. Clogged metering jet in the carb. Sticky carb float. Oversize air gap to flywheel from coil. Partial shear of flywheel shear pin. Leaky spark wire. Old, or poor quality motor oil. Grass caked under the deck. Dull blade. Want some more possiblities?

some years ago for safety reasons the feds limited the blades tip speed, cutting it dramatically. this cut effective power.

thats why horse power climbed while perform,ance decreased a lot.

its the age of the mower

A few weeks ago. Judging by the junk in his yards his blade is in terrible shape with all the rocks and bricks in it.

flat and not a rider.

Techumsa engine - that's the problem. Just wait until you have to have the engine worked on - for the same money, you can buy a new mower

Bob-tx

All kinds of possibilities, none of which are the brand in a case like this. YOu have things like the following that can affect how well they work:

-- Engine tuned? Just like a car they need an occasional tune-up based on how they're used.

-- Environment? Used in dusty/not dusty places? Ever replaced the air filter?

-- Using old or fresh gas?

-- Water in the fuel?

-- Fuel filter changed?

-- Tire pressures, if applicable, set right?

-- Compared at same time or different times? Weather, humidity, etc etc etc all can make a difference.

-- Engine clean? Fins clean? Debris cleaned out? Air flow OK?

-- Proper oil?

-- Past Preventive Maintenance record?

-- Blades sharp?

-- Blades aligned properly?

-- Belts all good?

-- All pulleys tight & rolling free?

-- Idler arms set properly?

-- Hours logged on the engines? (Here, brand CAN make a difference!)

-- Good overall design of the mechanics?

-- ...

AS you can see there are a LOT of reasons for a difference as you mention. I noticed somoene said 8 HP was fine for a 3-blade deck, which is nonsense. 8 HP is seriously under-powered and a very hard combination to find, actually. A few of the other ego-boast guesses I saw were nearly as silly too. Without having them sitting side by side in my garage to test/adjust/observe and maybe repair, a person can't really give you a definitive answer to this one. If I were forced to guess, I'd say an engine tune-up, blade sharpening and deck adjustments are the place to start.

Cheers,

Twayne`

Read previous post, changed about a month ago. Not dusty

fresh gas

Doubt it.

no fuel filter

not a rider

always had low power

cleaned

yes

again, read previous posts. My son's yard is full of rocks and hidden bricks, which I hit numerous times

Single blade on a push mower

See above and previous posts

See above

See above

mine had no power from the start. I initially chalked it up to pollution controls of all new motors

Good question. I am not a lawn mower engineer so can't comment on design.

replaced the air

humidity, etc

is running speed fast enough? might be a govenor problem...........

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