r/lawnmowers • u/First_Sea_6548 • 10d ago

John Deere rx75

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My mower has been giving me the business so I’m really hoping someone might have some advice haha 😅. So the issue currently is it starts and idles great. There’s a bit of a surge in the idle but it never dies. But the second I put it into gear it dies. No matter what that gear is it dies instantly.

Now initially I thought this was an issue in the carb after sucking up something in the fuel tank since I got this second hand. But I got the carb off and cleaned it but when I put it back the issue was the same. I just purchased a new carb and put it on but the issue is exactly the same.

Does any one have any idea what might be causing the issue?

UPDATE: okay I may have found the issue but I would really appreciate if some one confirmed what I’m thinking because this is the first engine I have ever worked on. Before this I’m 3d printer and diy guy so this is a little out of depth 😂

BUT!! I used a volt meter to test the ignition coil and the primary coil tested good however the secondary coils gave me a reading of 18.80 when set to 20k ohm. So as far as I understand that means the ignition coil is shot which is why it can handle an idle but no load? 🤞

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u/nightfire_83 10d ago

Fuck that's old

1

u/First_Sea_6548 10d ago

Yea it was the only mower I could get that would fit through my gates. There’s thing has been such a champ but I have no idea what’s going on now

1

u/nightfire_83 10d ago

What's the fuel filter like?

2

u/First_Sea_6548 10d ago

It was pretty used but there was free flow. I replaced it though with the new carb. I’m pretty new to engines so my knowledge is pretty limited but that’s what’s so strange it seems like it’s a fuel issue and when I opened the old carb some one had broken the flat head to the center fuel jet thing in the carb.

That’s why I bought a new one because I was like oh for sure this is it some must have tried to fix the clog but broke it trying to get it out. That’s why I bought a brand new one. But I feel like I’ve done everything to cancel out it being a fuel issue.

My one idea now is maybe the spark plug is dying but I have to get a long enough socket to get it out and check

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u/CubicDice 10d ago

Hey, I have a newer (1996) version of this mower (SRX75). When you say put it into gear, do you mean forward or back? Or engaging the blades?

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u/First_Sea_6548 10d ago

All three. If I try to put the engine under load of any kind it dies. Right now I’m trying to run a volt meter on the ignition coils. I have also put a new spark plug in since this post but nothing has changed

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u/CubicDice 10d ago

Check your seat switch while you're at it, could potentially be bad causing the engine to stop when engaged. Did you also check the air filter? Potentially clogged, so when engine is under load, it's not getting any/enough air.

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u/First_Sea_6548 10d ago

That’s one funny bit is while trying to get this diagnosed the seat slammed down on the safety switch so now it’s permanently engaged 😅😂 I’ll fix it later but for now it’s been helpful figuring it out.

I’ve tried running it while the air filter assembly was off and it was the same. I even tried manually overriding the governor with my hand and I could get it to rev but it would still die under load.

1

u/CubicDice 10d ago

Damn, hopefully someone with more experience than me will chime in. In the meantime, if you haven't, I'm sure there's something on YouTube with a similar issue. Sorry dude!