# 425 John Deere Twin V Starting Problem



## Twospeed (9 mo ago)

Working on this tractor that belongs to my father in law. He said the last time he used it, backfired loudly when we stopped and it has not started since. Unfortunately he has dementia so his memory is not always reliable. In any event, when I tried to start it, it sounded like a firing issue because no attempt to spit/spudder or anything. Here is what I have done. I know the fuel pump is working. I can hear it and see the filter fill up. I poured some gas in the carburetor just to test, nothing. I checked fuses on the panel. I pulled the spark plugs and cleaned although they looked fine. I did the thumb check over the cylinder hole and appears compression is not an issue. I attached the plug to the wire on each side and tested to see if the plugs were firing. They are. I read online about the cam shaft plastic gear stripping so pulled the value cover and the valves are moving. I have read about the time delay ignition and I am wondering about that although not sure exactly how it works. It seems like I would not have spark on the plugs if that was bad but not sure. Its the old style which is a square box so I don't think it has ever been replaced. Anyone have any ideas?


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## FredM (Nov 18, 2015)

Remove the blower housing and check the flywheel key, remove the flywheel nut and you will see a key slot in the flywheel and crankshaft, these have to be lined up, if not, then the key has sheared and the timing has shifted, most likely from the backfire.


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## Twospeed (9 mo ago)

Thank you for responding. When you say the blower housing, what are you referring to? I have attached a couple of pictures of what mine looks like. Thanks.


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## FredM (Nov 18, 2015)

If the photos had been attached with your original question, I wouldn't have made that suggestion, is that engine computer controlled??, can you quote the engine model number, I know it is a Kawasaki but need the model number to see if I can find a service manual for it. .


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## Twospeed (9 mo ago)

That is a good question that I have wondered myself. I assume it is because it has a computer board on the right hand side sitting on the tractor under the dash board. I am attaching a picture. I know from the serial number and another tag I found that it was manufactured in 1996. I also know the engine is a FD620D. Not sure if that is considered a model number or not and if not I am not sure where to find the model number on the engine. You will notice on the board if you zoom in there is a green light that comes on when you turn the key on. Just to the left of that light under the wire is a red light just like it. Not sure what would cause that to light. Just an observation.


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## FredM (Nov 18, 2015)

Thank you, that is the engine model #, that will give me a chance to find info on the engine, most importantly, engine timing checks, if indeed this engine has timing marks and where to find it, the engine has fuel supply, compression and spark, I feel that the timing is off and that is what I want to find out about.


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## Twospeed (9 mo ago)

Ok great. Upon further research, I have learned that they call that board an ignition module. In fact I found it for sale on Amazon and it looks like it comes with the ignition switch as well. So I have no idea what if anything it does anything to do with engine performance. Also something I read seemed to indicate it was tied in with some of the safety features which would make sense.


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## FredM (Nov 18, 2015)

Kawasaki FD620D Service Manual (Page 130 of 136) | ManualsLib







www.manualslib.com





I don't know if you have a service manual for your engine, the above is such and is downloadable and has lots of specs that will be handy for you, so it might pay you to read through this concentrating on the wiring diagram and attachables in the circuit and the trouble shooting section towards the rear of the manual, it will be a trial and error job, if you have a multimeter, there are values given for testing the ignition system.

If it was me, I would place which ever cylinder is #1 on TDC compression stroke and mark a white pencil line on the fan pulley and the engine mount bracket inline and use a timing light to check if the reluctor, pulsar coils and the igniter are firing in time with the engine, looking at the flywheel end of the engine, the rotation is clockwise, if the timing is in advance, the mark on the pulley should be before the stationary mark and if in retard, the pulley mark will be after the stationary mark, this is the cheapest way to find a fault in the electrics if that is the problem.


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## Twospeed (9 mo ago)

Ok thanks for this information. I appreciate it. I am going to try one thing that I stumbled across last night doing some more research and see if that works. I will let you know how it goes.


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## Twospeed (9 mo ago)

Sorry for the delay in getting back but some other projects got in the way before I could get back to the tractor. It ended up being two issues. My son has some experience with Kohler engines so he came over and we checked the spark plugs. While they were firing, he felt like the spark was weak. It was more of a yellow spark than a white spark. We changed the plugs. I had read on line about the carburetor solenoid. I took out the solenoid and tested it and it was not working. I held my thumb over the port where it came out and the engine started right up. Got a new solenoid online and she now runs like a top. Thanks for all of your help. I will hang on to that manual for future reference. It is really impressive that people like you go out of their way to help strangers with something like this. Much appreciated.


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## FredM (Nov 18, 2015)

That is great you have the machine running now, thank you for replying which is a bonus, happy Easter.


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## Hodado (12 mo ago)

I had the same issue and changed a sensor and it started right up,danged if I remember what they called it but I do remember that there was two sensors and I replaced the cheaper one to get it started


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