RK25 fuel shut off solenoid won't allow engine start

   / RK25 fuel shut off solenoid won't allow engine start #1  

crofutt

Bronze Member
Joined
Jun 28, 2005
Messages
59
Location
Pacific Northwest
Tractor
Jinma 354
Hello, I have a 1-1/2 yo RK 25 that won't start. The shut off solenoid, when the key is on should retract. I replaced the solenoid thinking it was bad but the new one is the same way. If I push the plunger in, it stays in until turned off then it won't retract. I've been removing the solenoid, turning on the key, push the plunger in then reinstall the solenoid. I can run the tractor until shut off, then won't start.
RK doesn't supply a wiring diagram even to their mechanics at their stores. If I had one maybe I could figure something out. There are 3 wires going to the solenoid, 12 volts when the key is on one wire, other two have no voltage (assuming one is the negative). But that 3rd wire may be something to troubleshoot but... No diagram...
Anyone else had this problem or have a suggestion what to try next? Or knows how to get a wiring diagram.
Thanks
Bill
 
   / RK25 fuel shut off solenoid won't allow engine start #2  
In the absence of wiring diagram ,if you can't wing your way through wires,I'd suggest replacing shut off with an aftermarket valve and using a toggle switch to control the valve. Cheaper would be a simple manual valve with push-pull cable.
 
   / RK25 fuel shut off solenoid won't allow engine start #3  
Hello, I have a 1-1/2 yo RK 25 that won't start. The shut off solenoid, when the key is on should retract. I replaced the solenoid thinking it was bad but the new one is the same way. If I push the plunger in, it stays in until turned off then it won't retract. I've been removing the solenoid, turning on the key, push the plunger in then reinstall the solenoid. I can run the tractor until shut off, then won't start.
RK doesn't supply a wiring diagram even to their mechanics at their stores. If I had one maybe I could figure something out. There are 3 wires going to the solenoid, 12 volts when the key is on one wire, other two have no voltage (assuming one is the negative). But that 3rd wire may be something to troubleshoot but... No diagram...
Anyone else had this problem or have a suggestion what to try next? Or knows how to get a wiring diagram.
Thanks
Bill
Sounds like a flaky relay bill. See if you can find a worrying diagram for the equivalent tym. The engine is different, not much else is.

I keep a spare 'known good relay' handy to swap and test . If it is a relay the numbers on top will lead you to a replacement one.
 
   / RK25 fuel shut off solenoid won't allow engine start #4  
Hello, I have a 1-1/2 yo RK 25 that won't start. The shut off solenoid, when the key is on should retract. I replaced the solenoid thinking it was bad but the new one is the same way. If I push the plunger in, it stays in until turned off then it won't retract. I've been removing the solenoid, turning on the key, push the plunger in then reinstall the solenoid. I can run the tractor until shut off, then won't start.
RK doesn't supply a wiring diagram even to their mechanics at their stores. If I had one maybe I could figure something out. There are 3 wires going to the solenoid, 12 volts when the key is on one wire, other two have no voltage (assuming one is the negative). But that 3rd wire may be something to troubleshoot but... No diagram...
Anyone else had this problem or have a suggestion what to try next? Or knows how to get a wiring diagram.
Thanks
Bill
The third wire should connect to the starting circuit somehow. It should get power when the starter is engaged. I have no idea how they did that on your model, but I suspect that if you can "jump" 12 volts to that third wire for a second with the key on, the solenoid will work just fine for you. If so, and you can't find the problem in the wiring, you can always get "creative" and find your own way to do that. It only needs a couple seconds of power. Any more and it will damage the solenoid coil.

Whatever it takes would be better than removing the solenoid every time.
 
   / RK25 fuel shut off solenoid won't allow engine start #5  
If its one and a half years old it should be under warranty.
 
   / RK25 fuel shut off solenoid won't allow engine start
  • Thread Starter
#6  
The third wire should connect to the starting circuit somehow. It should get power when the starter is engaged. I have no idea how they did that on your model, but I suspect that if you can "jump" 12 volts to that third wire for a second with the key on, the solenoid will work just fine for you. If so, and you can't find the problem in the wiring, you can always get "creative" and find your own way to do that. It only needs a couple seconds of power. Any more and it will damage the solenoid coil.

Whatever it takes would be better than removing the solenoid every time.
With black as ground, powering the red with energize the coil enough to hold the plunger in if I help it in. However, powering the white wire snaps the solenoid in. Makes me wonder if the white is only used initially to activate solenoid and then the red holds it retracted.
I'm leary of powering the white full time as it seems to draw a lot of current. I could I suppose place a momentary push button switch on the wire.
But, that doesn't tell me what's wrong. Going to pull the dash apart to get to the ignition switch, see if that white wire goes there...
 
   / RK25 fuel shut off solenoid won't allow engine start
  • Thread Starter
#7  
You're right. The local mechanic at RK has no idea and I don't have any confidence in him being better at this than I especially with no wiring diagram.
Further, I have to get it there for service which is very expensive.
They offer a mobile mechanic to come to my house. Costs $150.00 of he can fix it there, $250.00 of he takes it to the shop where the mechanics is I have no confidence in. Something to consider if planning to buy a RK tractor...
 
   / RK25 fuel shut off solenoid won't allow engine start #8  
With black as ground, powering the red with energize the coil enough to hold the plunger in if I help it in. However, powering the white wire snaps the solenoid in. Makes me wonder if the white is only used initially to activate solenoid and then the red holds it retracted.
I'm leary of powering the white full time as it seems to draw a lot of current. I could I suppose place a momentary push button switch on the wire.
But, that doesn't tell me what's wrong. Going to pull the dash apart to get to the ignition switch, see if that white wire goes there...

I think a “pull in” wire and a “holding” wire are sometimes typical for a solenoid.
Sounds like your solenoid might work fine, but whatever upstream (a relay, or safety switch, key switch, etc..) isn’t telling it to.
 
   / RK25 fuel shut off solenoid won't allow engine start #9  
With black as ground, powering the red with energize the coil enough to hold the plunger in if I help it in. However, powering the white wire snaps the solenoid in. Makes me wonder if the white is only used initially to activate solenoid and then the red holds it retracted.
I'm leary of powering the white full time as it seems to draw a lot of current. I could I suppose place a momentary push button switch on the wire.
But, that doesn't tell me what's wrong. Going to pull the dash apart to get to the ignition switch, see if that white wire goes there...
I never said to power the white wire full time. I said "jump" it with 12 volts for a second with the key on. Anything longer than that will cause problems.

I couldn't say how they engineered the system to work. Every manufacturer has a different plan when it comes to the "safety" circuits. Most all tractors have the same basic outcome, but can be all together different in how they get there.
 
   / RK25 fuel shut off solenoid won't allow engine start #10  
from my basic reading on here, you have it figured out, one initially pulls it all the way out (white wire i believe you said) and the red holds it.

white should only be powered during starting. trace the white wire, and see where its broken, its prolly tied directly to the ignition switch.
 
 
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