These are the Briggs & Stratton, 6.75 Vertical Shaft, side-valve quantum engines, that are primarily installed on walk behind mowers. To be more specific, this is the engine that is installed on my Toro SR4 Super Recycler 20055 mower. I have owned my Toro for 5-years, and this is what I think of my engine.
Recommend this product?
COMPANY INFO: Founded in 1908, Briggs & Stratton has been one of the most widely known small engine companies, in the world. Located in Wauwatosa, Wisconsin, B&S in my opinion, has been making some of the best engines to go onto lawn mowers, pressure washers, ETC. Their original cast-iron engines were known for their durability. However, the company's success was not established, until following the development of lightweight aluminum engines in 1953.
FEATURES: This engine has a 190cc-displacement equal to 6.75-HP. It uses recoil starting, and uses a primer bulb. This is a 675 series engine, quantum side-valve, vertical shaft. Shaft diameter is 7/8" with a 3/16" keyway. It uses a single cylinder, made of aluminum alloy. The air cleaner uses a automotive style pleated air filter. Fuel tank is 1.6 quarts. 20-ounce oil capacity, splash lubrication. Electronic ignition with mechanical governor. Uses a float carburetor. Auto compression release, 3,100 top speed RPM. (Revolutions Per Minute)
Manufacture Warranty: 24 months parts / 24 months labor.
Toro Warranty: GTS 5-Year Warranty
MY THOUGHTS: I really like how B&S simplified the construction and operation of the quantum engine. The carburetor is easy to get to, if you need to service it. Just remove the air cleaner cover, and air cleaner housing. The (RJ19LM) sparkplug is easy to get to and replace, as it is in the front of the engine, with no obstructions. It is also relatively easy to keep the engine clean, as there are not a lot of obstructions, and allow compressed air to blast the debris away. The top of the engine has a plastic shroud, which can be easily removed, if you need to service the coil, or other electrical wiring.
While this engine does not use overhead valves, which allow for cooler running, it also does not leak oil. In the past, I owned a Scotts mower which had the older B&S overhead valve Inteks on them. For some reason, as it became 3-years old, it began to leak oil around the valve cover. Apparently, they were all known to do that. Though its an older side-valve design, I find it is extremely reliable, and does not require adjusting of the valves, as opposed to the OHV design.
MY EXPERIENCE: This really is a great reliable engine, not only for its simplistic design, but its power to tackle the task. When I first bought my Toro mower, this engine started up on the first pull after only 3-prime pushes to the primer bulb. It is now 5-years later, and this engine still starts, on the first pull, every time! Because it does not have a throttle, the engine is set to a fixed optimum speed.
When mowing short grass 2 to 6 inches, this engine never bogs down a bit! It tackles the task as if it was a knife cutting butter. When mowing 12" of grass, the engine does slow down a bit, but will not stall unless you are mowing too fast. What I don't like about the engine, is that it is loud. Out of all the engines on the market, these are probably the loudest. Ranging between 85 to 90 decibels, hearing protection is recommended. The other thing is, they don't really burn clean, a oil odor can be detected from the exhaust.
CONCLUSION: Though it has an oil burning scent from the exhaust, I don't seem to ever have the need to top off the oil. When it comes to wanting the best engine on the market, these are not it. However, if you are looking for reliability, these engines are far superior, due to their simplistic design. When I ever have to buy a small walk behind mower again, I will be looking for one that has a B&S quantum on it. 5 out of 5.
Thanks goes to Dawn for adding this listing to the database so quickly!
I have ran regular SAE 30 oil in this engine for 5-years now, the engine has continued to run strong in all that time. However, as I wish to extend the engine life, and wish to do less oil changes, I switched out the Delo 400 oil. I am now using Valvoline 10W-30 Max Life Synthetic. Before I did this though, I ran MMO in the oil for 3 months to clean out the crankcase and carbon deposits.