Export thread

John deer gx75 no start

#1

Jakob27724

Jakob27724

I have a John Deere gx75 and it won’t start after I parked it for winter. It’s has great compression and a clean carb and is getting fuel. So I know it is ignition, it cranked over fine and has great spark but it still won’t fire. I was wondering is if it has some sort of timing issue with the spark if that’s even possible.


#2

Scrubcadet10

Scrubcadet10

i would say the flywheel key may have sheared, but usually they don't shear when just sitting parked ;)
How did you verify it's getting fuel? does the spark plug smell like fuel?
remove the airfilter and spray starting fluid, carb cleaner/parts cleaner or a small amount (tablespoon or so) of gasoline straight through the intake. then try to start. if it runs and dies you've got a fuel delivery issue, most likely a dirty carburetor.


#3

Jakob27724

Jakob27724

Scrubcadet10 said:
i would say the flywheel key may have sheared, but usually they don't shear when just sitting parked ;)
How did you verify it's getting fuel? does the spark plug smell like fuel?
remove the airfilter and spray starting fluid, carb cleaner/parts cleaner or a small amount (tablespoon or so) of gasoline straight through the intake. then try to start. if it runs and dies you've got a fuel delivery issue, most likely a dirty carburetor
Click to expand...


#4

Jakob27724

Jakob27724

I know it’s getting fuel because I have sprayed fuel in the spark plug hole quick put everything back on and it did nothing I also sprayed the carb and through then carb into the engine no luck at all so I’m thinking it’s timing


#5

Scrubcadet10

Scrubcadet10

Okay. Probably so.
And did you use a spark tester, or did you ground the plug to the engine block? Plug could be bad.
The main thing in ignition timing is the flywheel key it aligns the flywheel to the crank.


#6

Jakob27724

Jakob27724

Scrubcadet10 said:
Okay. Probably so.
And did you use a spark tester, or did you ground the plug to the engine block? Plug could be bad.
The main thing in ignition timing is the flywheel key it aligns the flywheel to the crank.
Click to expand...
It had great spark just won’t start I was wondering what ignition system it had or if it could be timing from the ignition


#7

Scrubcadet10

Scrubcadet10

did you check the spark with a tester like this, or ground the plug against the engine block?. 1614290542399.png


#8

Scrubcadet10

Scrubcadet10

Anyhow, on the ignition system, it depends on the 'age" of your engine. I believe that model uses a FC290V (if you can get the complete engine model # that will be very helpful, FC290V_ _ _ _)
Most consist of your Ignition Coil (sometimes called a magneto) 1614295235470.png
Flywheel which has the magnet to produce the current and of course the spark plug.
Now, most FC290's also have an Igniter, 1614295301826.png
Which is basically takes the place of points, and usually when they stop working, you have no spark at all (From my experience).

So since you've tried spraying in the fuel in the plug hole and you've got good spark, i think the next step is to remove the blower housing and check the flywheel key.
this video gives a good "general info" on the flywheel key.
you can see it's sheared in the video... now if the key is good it will make a perfect square in the slot.


#9

1

100 td

Parked running, now won't start. Safety switch or fuel 99% of time, varnish in carb, water or gunk in carb, crap fuel, electric clutch switch, brake or seat switch, less than 1% chance of timing fault.


#10

Scrubcadet10

Scrubcadet10

100 td said:
Parked running, now won't start. Safety switch or fuel 99% of time, varnish in carb, water or gunk in carb, crap fuel, electric clutch switch, brake or seat switch, less than 1% chance of timing fault.
Click to expand...
that's what i figured, but he said it wont even start with fuel directly in the plug hole. and has good spark.


#11

Jakob27724

Jakob27724

Scrubcadet10 said:
did you check the spark with a tester like this, or ground the plug against the engine block?. View attachment 55557
Click to expand...
I grounded to the engine block but I had to get it positioned just right to spark


#12

Jakob27724

Jakob27724

Scrubcadet10 said:
Anyhow, on the ignition system, it depends on the 'age" of your engine. I believe that model uses a FC290V (if you can get the complete engine model # that will be very helpful, FC290V_ _ _ _)
Most consist of your Ignition Coil (sometimes called a magneto) View attachment 55558
Flywheel which has the magnet to produce the current and of course the spark plug.
Now, most FC290's also have an Igniter, View attachment 55559
Which is basically takes the place of points, and usually when they stop working, you have no spark at all (From my experience).

So since you've tried spraying in the fuel in the plug hole and you've got good spark, i think the next step is to remove the blower housing and check the flywheel key.
this video gives a good "general info" on the flywheel key.
you can see it's sheared in the video... now if the key is good it will make a perfect square in
Click to expand...


#13

Jakob27724

Jakob27724

Scrubcadet10 said:
Anyhow, on the ignition system, it depends on the 'age" of your engine. I believe that model uses a FC290V (if you can get the complete engine model # that will be very helpful, FC290V_ _ _ _)
Most consist of your Ignition Coil (sometimes called a magneto) View attachment 55558
Flywheel which has the magnet to produce the current and of course the spark plug.
Now, most FC290's also have an Igniter, View attachment 55559
Which is basically takes the place of points, and usually when they stop working, you have no spark at all (From my experience).

So since you've tried spraying in the fuel in the plug hole and you've got good spark, i think the next step is to remove the blower housing and check the flywheel key.
this video gives a good "general info" on the flywheel key.
you can see it's sheared in the video... now if the key is good it will make a perfect square in the slot.
Click to expand...
Yes that is the right engine and I just ordered a carb because it was a little vanished but the main jet was clear and I ordered the igniter, along with a spark plug and air filter


#14

Scrubcadet10

Scrubcadet10

Alrighty. try those before you follow my advice on the flywheel key.


#15

H

Hitechluddite

I don't know of any mowers that will turn over if the safety circuits are not properly engaged. I would replace the plug first. they are cheap and a new one never hurts.


#16

VRR.DYNDNS>BIZ

VRR.DYNDNS>BIZ

Scrubcadet10 said:
Okay. Probably so.
And did you use a spark tester, or did you ground the plug to the engine block? Plug could be bad.
The main thing in ignition timing is the flywheel key it aligns the flywheel to the crank.
Click to expand...
The point of this question unanswered is the plug may be your cause


#17

1

100 td

larrykoivula said:
99% its dirty coil& flywheel contacts-remove coil=clean contacts on both with emery cloth-contact settings are thickness of a buisness card-then clean spark arrestor screen on muffler if not done--always the first checks-let me know if it works
Click to expand...
100% it's not, he has stated it has great spark!


Footer Links 1

Top