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Small Engines (Lawn Mowers, etc.)/John Deere ZTRAK 737 zero turn radius mower


Hello! 2 problems I have #1- accidental added approx 1 gal of gas/2cycle oil mix into mower. Problem didnt appear until third mowing afterward. Engine started to run ragged,spit&sputter,and backfire--but not stall. It sounded like not enough fuel. I figured the tainted gas was out of system by third mowing--so I added new gas,changed fuel filter, spark plugs,and both ignition coils(airgap set with new feeler gauges and bolts torqued to specs) then I added seam foam treatment to fuel tank to clean any thing out of fuel lines carb etc. Engine still sputtered as expected by addition of sea foam,but got better--so that for two mower ran almost perfect. Then last mowing I added fresh gas and some fuel stabil(fuel stablizer)to get mower ready for winter. Then is was worse than ever--not only backfired loud,but sputtered and actually stalled many times. It sound very much like not getting gas. Thats 1st problem.... 2nd problem i will put in another question!!! Thank you very much for your expert help!!!!!

I'd start by removing, dis-assembling and cleaning the carb with compressed air from an air compressor and spray can carburetor cleaner.

Newer carbs are very sensitive due to strict emissions controls.

I recently had to replace a carb on a JD...could not get the original carb to run right.  Customer was so mad about replacing the carb as the mower had very low hours on it he stated he wanted to sell it.  

Called him up to see if he had sold it or still wanted to sell it and he said it had never ran as good as after replacing the carb.  He said he loves the mower now and does not want to sell it.

Try cleaning the carb first.


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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