743B engine shutdown solenoid

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Tazza

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Does anyone in here have a 743B at all? or any other Kubota engine that is fitted with a shut down solenoid? I am after pictures of just how they are fitted to the engine. I have one that i took of a 743B that was at an auction a few months back, but i didn't get enough detail of just where it linked to the engine shut off lever, it shows where its mounted to the engine, no more. I would rather a 743B as it uses the same V1702 engine as my 743 uses.
If you have one, can you take a few piccies for me?
I want to convert my manual shut off cable to an electric setup so i can turn it off with the key and it will automatically shut off with the use of a “watch dog” setup of it detects over temp, low oil pressure or low water level.
If you can't post them on here please send them to [email protected]
Thanks for any help you can provide.
 

Tazza

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This is the pic i have, i just need a pic from the side.
Electric%20shut%20down.jpg
 

skidsteer.ca

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This is the pic i have, i just need a pic from the side.
Tazz, This is of my 773 G same solinoid, I measured the stroke with a dial indicator and got .71 of a inch.
IMG_0088.JPG

IMG_0089.JPG

IMG_0090.JPG

Last photo is down from top. There is a ball and socket arrangement in the middle of the plunger shaft for some reason. Must be to prevent side load on the plunger, I guess, (plus the small ball joint rod end at the lever). If you can't get a pic of your model, maybe this will help. I know that its fairly important that solinoids of this type seat firmly when activated, And that the one power wire can only take current for a few seconds at a time, and then the solinoid will burn out. Both hots get power for a few seconds, then the one shuts power off, the other hot wire stays with power to hold the soliniod in, but at a much lower current/amp level to prevent burn out
Ken
 

Tazza

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Tazz, This is of my 773 G same solinoid, I measured the stroke with a dial indicator and got .71 of a inch.



Last photo is down from top. There is a ball and socket arrangement in the middle of the plunger shaft for some reason. Must be to prevent side load on the plunger, I guess, (plus the small ball joint rod end at the lever). If you can't get a pic of your model, maybe this will help. I know that its fairly important that solinoids of this type seat firmly when activated, And that the one power wire can only take current for a few seconds at a time, and then the solinoid will burn out. Both hots get power for a few seconds, then the one shuts power off, the other hot wire stays with power to hold the soliniod in, but at a much lower current/amp level to prevent burn out
Ken
Thats exactly what i needed!
The data i have on the solenoid tells me how to wire it up too, its exactly how i was thinking of doing it. Connect the pull coil to the starter so it pulls back only while cracking and wire the hold coil te the “on” power from the ignition switch. As for the seating, the data says that if its not adjusted correctly (not seating properly) the coil will just let go so you can't use it when its not rite, preventing burn out.
Thanks again!
 

skidsteer.ca

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Thats exactly what i needed!
The data i have on the solenoid tells me how to wire it up too, its exactly how i was thinking of doing it. Connect the pull coil to the starter so it pulls back only while cracking and wire the hold coil te the “on” power from the ignition switch. As for the seating, the data says that if its not adjusted correctly (not seating properly) the coil will just let go so you can't use it when its not rite, preventing burn out.
Thanks again!
Our miller welder uses one of these types of solinoids to throtle up when welding. It has a spring in the pull linkage to allow some give to insure the plunger seats fully.
You might want to retain some manual way of locking on the fuel and unhooking the pull in wire.. To protect the solinoid should extended crank intervals become necesary, (ie fuel filter bleeding)
The bobcat ones have been good to me , no burn outs, but we tried a similar Murphy Switchgage (www.fwmurphy.com) watchdog system on 2 skidders with 6v53 detroit diesels, (known for loseing oil press and turning bearings) they of course have no electric shut off and a solinoid was necessary. But they kept burning out for various reasons. They system was too complex and those engines have so little oil pressure at a idle that we kept getting false shutdowns. Which really agrevated the operator and myself, the trouble shooter.
In the end we gave up on shutting of the engine and set up a light to “blind” the operator should the watchdog get a trip/shutoff reading from one of the guages. The operator could then check the guage to verify if it was false or correct.
Also I know my 93 753 had a spdt relay wired into the pull in wire, so I don't think it got power from the starter. Though I don't see why that won't work.
Its somewhat common for those “spdt” relays to wear out @ 2000 hrs and give sporadic start problems by not always turning on the fuel.
Just a few thoughts.
Ken
 

Tazza

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Our miller welder uses one of these types of solinoids to throtle up when welding. It has a spring in the pull linkage to allow some give to insure the plunger seats fully.
You might want to retain some manual way of locking on the fuel and unhooking the pull in wire.. To protect the solinoid should extended crank intervals become necesary, (ie fuel filter bleeding)
The bobcat ones have been good to me , no burn outs, but we tried a similar Murphy Switchgage (www.fwmurphy.com) watchdog system on 2 skidders with 6v53 detroit diesels, (known for loseing oil press and turning bearings) they of course have no electric shut off and a solinoid was necessary. But they kept burning out for various reasons. They system was too complex and those engines have so little oil pressure at a idle that we kept getting false shutdowns. Which really agrevated the operator and myself, the trouble shooter.
In the end we gave up on shutting of the engine and set up a light to “blind” the operator should the watchdog get a trip/shutoff reading from one of the guages. The operator could then check the guage to verify if it was false or correct.
Also I know my 93 753 had a spdt relay wired into the pull in wire, so I don't think it got power from the starter. Though I don't see why that won't work.
Its somewhat common for those “spdt” relays to wear out @ 2000 hrs and give sporadic start problems by not always turning on the fuel.
Just a few thoughts.
Ken
I can buy a special relay that automatically engages the pull coil and then turns off to let the hold coil hold it in place if there is a burn out problem. The solenoid is all of $60, so i figure its worth a go, it is covered by warranty.
As for burnouts from extended cranking, how delicate are the coils? i thought they would be able to handle say 10 or so seconds, which is generally more than enough time to get the engine started. If not, you need a longer glow time.
 

skidsteer.ca

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I can buy a special relay that automatically engages the pull coil and then turns off to let the hold coil hold it in place if there is a burn out problem. The solenoid is all of $60, so i figure its worth a go, it is covered by warranty.
As for burnouts from extended cranking, how delicate are the coils? i thought they would be able to handle say 10 or so seconds, which is generally more than enough time to get the engine started. If not, you need a longer glow time.
Tazz
For these I can't say. never had one fail.
For the fw murphy ones, they were not warrantied for burn out, and about 20 to 30 seconds, once, would ruin them.
Ken
 

Tazza

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Tazz
For these I can't say. never had one fail.
For the fw murphy ones, they were not warrantied for burn out, and about 20 to 30 seconds, once, would ruin them.
Ken
Hey ken, when the solenoid is fully retracted (in the run position) does it touch the right hand stop? I have sort of set mine up and i'm just trying to work out how far back to the “run” position it must sit. I just don't want to have it set wrong and destroy my injector pump.
That ball joint was needed, i found out last weekend when i set it all up. I had it all bolted in and it would bind up as the lever moved. After actually using my brain i thought to my self, you idiot! of course it was needed. As the arm moves, it goes in an arc making the arm move up and down. I should have thought about it a bit more.
I just want to fine tune it so it stops correctly. I want to move the lever as far forward as i can so the spring pressure is enough to stop the engine instantly. As it is now, it goes forward a little slow because there isn't quite enough force against the lever which i can fix with adjustments or adding a spring.
Thanks, and sorry for harassing you yet again.
 

skidsteer.ca

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Hey ken, when the solenoid is fully retracted (in the run position) does it touch the right hand stop? I have sort of set mine up and i'm just trying to work out how far back to the “run” position it must sit. I just don't want to have it set wrong and destroy my injector pump.
That ball joint was needed, i found out last weekend when i set it all up. I had it all bolted in and it would bind up as the lever moved. After actually using my brain i thought to my self, you idiot! of course it was needed. As the arm moves, it goes in an arc making the arm move up and down. I should have thought about it a bit more.
I just want to fine tune it so it stops correctly. I want to move the lever as far forward as i can so the spring pressure is enough to stop the engine instantly. As it is now, it goes forward a little slow because there isn't quite enough force against the lever which i can fix with adjustments or adding a spring.
Thanks, and sorry for harassing you yet again.
Tazza
No problem, except my 773 is up at the lake working.
I'll be up there after lunch, so I'll look and let you know, prob tomorrow nite
Ken
 

Tazza

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Tazza
No problem, except my 773 is up at the lake working.
I'll be up there after lunch, so I'll look and let you know, prob tomorrow nite
Ken
Thanks
When you get time, no rush. Its not something i have to do rite away.
 

skidsteer.ca

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Thanks
When you get time, no rush. Its not something i have to do rite away.
Tazza
There is about 1/16” between the cast stop on the pump and the arm. The soliniod actually bottoms b4 the stop makes contact with the arm.
The engine was off and I pulled the lever manually, so if there is any play in the “ball joints” would add to the 1/16”
Ken
 

Tazza

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Tazza
There is about 1/16” between the cast stop on the pump and the arm. The soliniod actually bottoms b4 the stop makes contact with the arm.
The engine was off and I pulled the lever manually, so if there is any play in the “ball joints” would add to the 1/16”
Ken
Thanks for that, thats about how i have it set now.
I will fine tune it to those measurements you gave me.
Its working how it is now, just a little slow turning off because of the vacuum inside the rubber cover on the solenoid makes it move forward slowly. I'm going to ask the guy i bought it off, if i can punch a small hole in the cover without causing damage. The starter solenoid is sticky and needs replacing, some times it starts and the starter will not stop spinning. So much for a brand new solenoid!.
Its still going, i really want it all finished so i can move on to another machine that i want to sell! Still a few more weeks worth of weekends to go.... Need to paint and attach the rear door and finish the bobtach locking bits, then setup the warning lights in the ROPS.
 
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