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Small Engines (Lawn Mowers, etc.)/FD620D engine replacement w/FD750D


I have a Cub cadet 3208 with a FD620D Kawasaki engine in it.  I would like to replace it but KW doesn't make it any more, they tell me the only way to fit it is to rebuild it.  Have read that some people state it isn't rebuildable and spend thousands finding this out so would like to replace it instead of rebuilding.  I found the FD750D will fit in the mower, bolts, shaft etc. match up but I have an vacuum operated PTO that needs another vacuum connection on the intake manifold to operate.  In talking to KW they can't tell me if it comes with this connection.  If it doesn't can I add one?  I have checked out the elec connections and the other difference is the FD620D uses an igniter and the FD750D doesn't but in tracing down the wiring diagram it looks like the keyed connection wiring is the same flow except will have to change a couple of wires for/to igniter to FD750 coil and grd through A switch terminal.  My engine number is FD620D-BS21.  The engine I am looking at purchasing is the FD750D-SO2.  Can you help me with the PTO vacuum connection.  Is it possible to add one?

Does the replacement engine you are looking at come with a vacuum port?  If so, can you install a t fitting to connect another vacuum line?

You could drill a hole in the replacement engine in a similar location as at the original engine.

Next time you are at Sears or a hardware store, take a look at the Briggs or Kohler engine mowers that have a vacuum operated fuel pump to see where those engine have their vacuum ports.

As for the electrical, that should be pretty easy.  Make sure you read the wiring diagram carefully as most igniters, or any ignition component, rarely has any power connected to them.  DO NOT ruin your igniter by connecting 12 VDC to it!


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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