Small Engines (Lawn Mowers, etc.)/TORO Engine Surge


TORO Super Recycler  Mod  20474  Ser  6905779  
Twice in the last 6 wks  when the mower started, a rather large puff of blue smoke came out.  No smoke after it was running.  Now when mower is first started, it runs OK but after a few minutes a surge or pulsating starts. It does not emit the smoke every time it starts,only has done it twice. This is an OVH engine.  Any thoughts?  Valve seals?  Thank you.  Chuck

Great engine on that mower...but it is getting old so a puff of blue/white smoke can be expected as the rings, piston and valve guides are wore.

Are you using SAE-30 oil?  How often do you change the oil?  Have you ever checked the valve clearance?

You can download the engine service manual from Toro's is the 49 page manual.

The surging is most likely caused by a fuel issue, usually the carburetor or a leaking intake part/gasket.  Since it takes a few minutes for the surging to begin the something may be warming up and expanding which then starts to leak.

When was the last time the carburetor and fuel system was cleaned and serviced?

Again, those were great engines and mowers.  Reliable and dependable.  It is difficult to find mowers today that were as good as the mower you have.


Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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