Finding the right fuel solenoid

[Tiger Small Engine]

I removed mine. it just unscrewed from the bottom of the bowl with a 1/2 thin spanner wrench like others I've changed. No need to take carb off. The PN you gave me was off a few mm off each measurement. I put in goggle search my engine model + fuel solenoid and I stumbled upon one with the right plunger tip and the same dimensions and I bought it. Won't be here till next week. Not sure if I'm going down the right path since it did have 34 ohms and didn't drop to 0 like it would've if it had a short. Unless something shorts when energized. Maybe it just has to be ran for a while before the ohms drop ri 0 and shorts out? I checked the red wire. Still haven't found any rub marks. I put a pic of my solenoid and the one I ordered.

Only two wire’s maximum, hot and ground. Some only have one wire, and use solenoid while screwed in for ground. Even on small electrical issues like this, sometimes bypassing is just better long term to eliminate problems. Don’t get caught up over a 10 ohms difference in reading. I read secondary resistance on ignition coils sometimes that are bad, and ohms out ok, then ultimately replace and problem goes away. Some issues are not black and white.

 

[Wirespider01]

Only two wire’s maximum, hot and ground. Some only have one wire, and use solenoid while screwed in for ground. Even on small electrical issues like this, sometimes bypassing is just better long term to eliminate problems. Don’t get caught up over a 10 ohms difference in reading. I read secondary resistance on ignition coils sometimes that are bad, and ohms out ok, then ultimately replace and problem goes away. Some issues are not black and white.

Thank you.

 

[Freddie21]

If you have not done so, remove the engine cover and you'll probably see the wires go across the top of the engine. Examine them and clean the engine while you're at this point. On some Briggs, the two wires go behind the starter and can get pinched there. An easy fix.

 

[Gord Baker]

Try another Ignition switch.

 

[Cajun power]

for testing: remove the anti back fire solenoid. (yes, fuel will drain out, have a small container handy to catch fuel). With fingers or the back of plastic handle screw driver, depress the pin into the solenoid. (engine OFF). Do this a few times. If it will not budge spray some wd-40. Try it again. Now, with anti back fire solenoid removed, key to start and you should be able to see the pin retract as it should. It's hard to listen to it click because you might confuse the click with the starter solenoid, which also can give a slight click sound too...so just watch the pin and see if it will retract. if not, try excercising the pin over and over with wd-40...try again...if it still will not budge, then you have some option:
1. meter the connector while you start and see if there is 12 volts. If there is no voltage, then you have a power supply problem. Go all the way back to the disconnect...usually there is a large disconnect somewhere between the anti backfire solenoid connector and the ignition switch. check the power there...if there IS power there, then you probably either have a bad connector or open wire between the connector and the anti backfire solenoid. often this is the wires getting crushed from factory zip ties somewhere along the route. Look at this zip tied locations. Sometimes the wires get borked and insulation loss across the engine or engine shroud, causing a short. Basically this option is looking for why you are not getting power to the anti back fire solenoid connector. If you are not getting power to the disconnect on ENGINE START, the continue tracing back from that connector to the ignition switch...looking for wire damage or a corroded or grounded spade connector on the ignition switch. (as preventative maintenance, I wd-40 ignition switches at least once a year..internally, they can corrode as well as the backside where the terminals can get junked up from debris, causing shorts between wiring connectors.
2. if you do have power to the anti back fire solenoid connector (at engine start), and there are no issues traced all the way back to ignition switch, then it's more than likely a faulty anti back fire solenoid device...either it's so gummed up that the solenoid failed, or as is the case usually these are cheaply made prone to fail devices that die over time.. You can if you want to, just delete the anti back fire solenoid from the engine and get a fine threaded bolt to hold the bowl of the carb with a simple bolt gasket to prevent leaks. If you are concerned about back fires, idle down before shutting engine off. I've done this many times and there is no downside to just deleting the device. If the engine pops in shutdown, I'm not losing sleep over it. But it rarely happens. anti back fire solenoids are expensive, but you can sometimes find alternate part numbers by cross referencing the carb..(versus trying to do it with the engine or mower model). So if you find the carb model number, look for the anti back fire solenoid that fits it and matches the wiring connector you have. Sometimes you find that there are many different part numbers for anti back fire solenoids that work for a carb. if you follow the mower parts list or engine parts list from the manufacturer they do not generally give you alternate parts that will actually work..and that are cheaper. I'm sure we can assume why they would not give this info out. :-(

 

[Wirespider01]

for testing: remove the anti back fire solenoid. (yes, fuel will drain out, have a small container handy to catch fuel). With fingers or the back of plastic handle screw driver, depress the pin into the solenoid. (engine OFF). Do this a few times. If it will not budge spray some wd-40. Try it again. Now, with anti back fire solenoid removed, key to start and you should be able to see the pin retract as it should. It's hard to listen to it click because you might confuse the click with the starter solenoid, which also can give a slight click sound too...so just watch the pin and see if it will retract. if not, try excercising the pin over and over with wd-40...try again...if it still will not budge, then you have some option:
1. meter the connector while you start and see if there is 12 volts. If there is no voltage, then you have a power supply problem. Go all the way back to the disconnect...usually there is a large disconnect somewhere between the anti backfire solenoid connector and the ignition switch. check the power there...if there IS power there, then you probably either have a bad connector or open wire between the connector and the anti backfire solenoid. often this is the wires getting crushed from factory zip ties somewhere along the route. Look at this zip tied locations. Sometimes the wires get borked and insulation loss across the engine or engine shroud, causing a short. Basically this option is looking for why you are not getting power to the anti back fire solenoid connector. If you are not getting power to the disconnect on ENGINE START, the continue tracing back from that connector to the ignition switch...looking for wire damage or a corroded or grounded spade connector on the ignition switch. (as preventative maintenance, I wd-40 ignition switches at least once a year..internally, they can corrode as well as the backside where the terminals can get junked up from debris, causing shorts between wiring connectors.
2. if you do have power to the anti back fire solenoid connector (at engine start), and there are no issues traced all the way back to ignition switch, then it's more than likely a faulty anti back fire solenoid device...either it's so gummed up that the solenoid failed, or as is the case usually these are cheaply made prone to fail devices that die over time.. You can if you want to, just delete the anti back fire solenoid from the engine and get a fine threaded bolt to hold the bowl of the carb with a simple bolt gasket to prevent leaks. If you are concerned about back fires, idle down before shutting engine off. I've done this many times and there is no downside to just deleting the device. If the engine pops in shutdown, I'm not losing sleep over it. But it rarely happens. anti back fire solenoids are expensive, but you can sometimes find alternate part numbers by cross referencing the carb..(versus trying to do it with the engine or mower model). So if you find the carb model number, look for the anti back fire solenoid that fits it and matches the wiring connector you have. Sometimes you find that there are many different part numbers for anti back fire solenoids that work for a carb. if you follow the mower parts list or engine parts list from the manufacturer they do not generally give you alternate parts that will actually work..and that are cheaper. I'm sure we can assume why they would not give this info out. :-(

Thanks. I've always had power at the solenoid. I unplugged the whole harness before it goes up into the ignition switch. I traced most of the wires all seem good. I put a new rectifier on JIC. I put a brand new solenoid in turned the switch and it popped the fuse. So I removed the red wire from the plug to the solenoid. Runs good but I haven't mowed with it yet. Still in the garage. I have to put the shroud back on. I was reassembling and I forgot to put the shroud on before mounting the gas tank. That tank is a pain where it's at. So I'll have to reloosen the gas tank to get the shroud down over. Seems like cub cadet did some over engineering on that and also you have to remove the whole battery and tray to get to fuse, then you have no battery to check fuse circuits. I have small jumpers that took care of that problem though. Just seems like some things weren't thought out that well at the engineering level. Probably to throw more business to the cub cadet service dealers. I'll let you know if it mows without blowing a fuse. if it does blow a fuse I'm going right to the ignition switch and putting a new one in. Oh and I was able to match a aftermarket solenoid up with mine going of the plunger tip and the dimensions of the solenoid. If anyone needs that part number I have it. You don't have to buy the rebuild kit if you already have a two wire solenoid plug like I did

 

[Cajun power]

Thanks. I've always had power at the solenoid. I unplugged the whole harness before it goes up into the ignition switch. I traced most of the wires all seem good. I put a new rectifier on JIC. I put a brand new solenoid in turned the switch and it popped the fuse. So I removed the red wire from the plug to the solenoid. Runs good but I haven't mowed with it yet. Still in the garage. I have to put the shroud back on. I was reassembling and I forgot to put the shroud on before mounting the gas tank. That tank is a pain where it's at. So I'll have to reloosen the gas tank to get the shroud down over. Seems like cub cadet did some over engineering on that and also you have to remove the whole battery and tray to get to fuse, then you have no battery to check fuse circuits. I have small jumpers that took care of that problem though. Just seems like some things weren't thought out that well at the engineering level. Probably to throw more business to the cub cadet service dealers. I'll let you know if it mows without blowing a fuse. if it does blow a fuse I'm going right to the ignition switch and putting a new one in. Oh and I was able to match a aftermarket solenoid up with mine going of the plunger tip and the dimensions of the solenoid. If anyone needs that part number I have it. You don't have to buy the rebuild kit if you already have a two wire solenoid plug like I did

A blown fuse is usually caused by a bad voltage regulator, yes. So good call. I'm not 100 percent, but there is also a diode that might be in the PTO circuit. This zenner acts to prevent back current from the PTO to the charging circuit when the PTO is first engaged at which time it produces a inrush of current and the consequential inductive reactance! (big words, simplified: some high amp solenoid like the PTO clutch system create quite a bit of resistance initially during startup.....the diode prevents that backflow of current from damaging the wiring and the voltage regulator. (I have an old dixie chopper that on the charging circuit, because the voltage regulator does not have an integrated diode!) If you have the time, research the wiring diagram for your mower and see if there is a diode...this could be the reason for the failure of the anti backfire solenoid. This is purely a guess on my part. I do not have the time right now to look up the wiring schematic and see the description and operation. You might also want to do a test of the PTO, and also inspect it visually to make sure there is not something wrapped around it, or even the mower spindles. Anything that binds of the belt driven PTO clutch and spindles could be drawing excessive amps! Here is a good video for testing the PTO

 

[Cajun power]

Thanks. I've always had power at the solenoid. I unplugged the whole harness before it goes up into the ignition switch. I traced most of the wires all seem good. I put a new rectifier on JIC. I put a brand new solenoid in turned the switch and it popped the fuse. So I removed the red wire from the plug to the solenoid. Runs good but I haven't mowed with it yet. Still in the garage. I have to put the shroud back on. I was reassembling and I forgot to put the shroud on before mounting the gas tank. That tank is a pain where it's at. So I'll have to reloosen the gas tank to get the shroud down over. Seems like cub cadet did some over engineering on that and also you have to remove the whole battery and tray to get to fuse, then you have no battery to check fuse circuits. I have small jumpers that took care of that problem though. Just seems like some things weren't thought out that well at the engineering level. Probably to throw more business to the cub cadet service dealers. I'll let you know if it mows without blowing a fuse. if it does blow a fuse I'm going right to the ignition switch and putting a new one in. Oh and I was able to match a aftermarket solenoid up with mine going of the plunger tip and the dimensions of the solenoid. If anyone needs that part number I have it. You don't have to buy the rebuild kit if you already have a two wire solenoid plug like I did

check this out also:

 

[Wirespider01]

check this out also:

Thanks Cajun Power. Before posting here I completely unplugged the PTO and turned the key over one click and the fuse blew. I also already disconnected the headlight harness and it popped the fuse. No flattened or Skinned wires. I've eliminated the fuel solenoid and the wire from the main connector (plug) in the harness.

I had about 15 fuses the night I started trouble shooting. I eliminated a lot of possibilities. I blew quite a few fuses but they are not expensive.

I'll see what happens when everything is heated up to normal mowing temp.

I don't think it's the coils or stator. I don't believe they would short until mower is cranking. I could be totally wrong on that. My best guess now if the machine blows another fuse it's the ignition switch. At least the the red wire contact for the solenoid. The switch is OEM and it has been in the rain sitting a few times from the old owner and me. Sometimes it just happens. The old owner kept it in the garage mostly and I store it in the garage for the most part.

 

[Cajun power]

yes, based on what you have done so far, the ignition switch might be badly corroded internally and shorting. I have a few other suggestions:

check the battery ground...the ground point and the cable itself. the chassis/engine acts as the negative common of these mower...if the ground cable is corroded, or there is something else like rust that prevents a good chassic/engine ground, the chassis/engine connection acts as high resistance...I would disconnect the battery ground (black) cable completely ( this is important because there is a non zero chance there might be a very small parasitic draw somewhere even with engine off and this will effect a proper cable ohm check). and ohm check it to make sure the cable isn't damaged. It should be zero (0) ohms. make sure your meter is good. test the leads before to make sure by touching them. that should read 0 ohms also for a good meter test. Now reattach the battery ground cable again to only the ground point on the chassis (do not connect to battery ground just yet). Now test from the ground cable end all the way back to the engine block. This should also read zero (0) ohms. if you get anything any resistance ohms, then your ground point to the engine through the chassis is not a good connection (this can happen on chassis that are bolted together, versus one single piece of steel. (anecdote: on my own gmc silverado, I was constantly replacing the fuel sender in the tank. due to age and rust the ground point from the battery through the chassis was not good continuity...the fuel sender was grounded at the frame under the bed of the truck. chassis resistance, point to point was almost 20 ohms. I solved this problem by running a 10 AWG stranded wire from the fuel sender forward to the engine compartment where the battery ground is bolted. I've never had to replace a fuel sender again! )

another thing to test are the electrical disconnect plugs. Sometimes due to corrosion, or heat damage internally wires can short, or just loose connections inside. (I like using dielectric grease on these connectors...it helps to prevent water ingress and junk and keeps the connectors from corroding over time) The easy way to test this is to remove wires upstream and down stream from the disconnects and then test continuity (ring it out). There is a process involved. say there are 7 wires in the connector. Take wire number one and ring that out to the other end of the connected wire. (sometimes the wire colors are different on each end of the connector, so visually see how they are connected. In this example you are ringing out wire 1 with wire 2, then wire 3, the wire 4..all the way to 6. There should be no shorts between wires. That is what you are checking to see. then take wire 2 and ring it to wire 3 thru 6 (you've already done wire 1 to 2 before)...and then ring out wire 3 to 4 thru 6...and then ring wire 4 to 5 thru 6. the ring out wire 5 to 6. If you get a ring out (continuity then the connector internally is shorting the wires that ring. (if you have a needle lead you can of course back probe the connector on either side, but I prefer to do the wires, because you can also check the wires at the same time (for resistance).