Kioti intermittent starting problems

[n4msl]

My DK40SE HST has had problems with intermittent starting for quite some time. My dealer supplied a new key switch that solved the problem the first time. The problem returned recently and I found that the start relay was not supplying current to the starter pull coil. I disassembled the relay and found the contact points burned. I burnished them with emery cloth and the problem was solved. I wonder if this relay is not responsible for many of the starting problems mentioned on this forum.

This particular tractor has two identical relays (blue) mounted on the firewall. To determine if the start relay was faulty, I simply switched the two relays, in place, and found that it started just fine. The relays are sealed, but with a soft material that is easy to remove. Pry off the cover and the relay mechanism is accessible. Reseal with any soft sealer.

Also, the start relay was incorrectly identified in the shop manual. Manually trace the starter pull coil wire from the starter back to the relay to identify the correct one.

 

[seacap04]

Welcome to TBN. You maybe on to something. I also had intermittent start issues when I first got my tractor used. I started pulling wiring connectors in the start circuit looking for corrosion. The connector to the start switch was not what I would call bad, but cleaning it was enough to end my start issues. I suspected high resistance somewhere in the circuit was the issue. Contacts in the relay maybe getting burned, and cleaning other connectors just lowers resistance enough to allow circuit to function. I was not thrilled with the fix, but it has worked for 2 years now. I also had an issue with the glow plug circuit. Really badly burned connector on glow plug bus bar. You might want to take a look before weather gets cold. I have now gone through every connector on this tractor. Thank you for your post.

 

[ritcheyvs]

Good idea swapping these relays. Another subscriber did this too and isolated his problem. I think many (if not all) Kiotis use a similar relay for the starter and stop solenoid.

A few comments. Dirt and/or corrosion in the key switch can impede any of the three actions needed to start the engine: (1) activate stop solenoid, (2) power up glow plugs, and (3) crank starter motor. Also, each of these functions use a relay to switch the higher current needed to operate the associated solenoid or glow plugs. Therefore, a defective relay will impair the associated function. The starter and stop solenoid relays provide power to solenoid coils which would cause a spark when the relay contacts open except for a "suppression diode" plugged into the wiring harness.

The burned points may be caused by a bad (in this case open circuit) suppression diode. Also, cleaning the contacts is usually a temporary fix. The original coating on these contacts is more durable than the metal under the coating. These relays are not expensive (less than $20, I think) so I'd recommend buying a new relay for the next time this happens. It would also be a good idea to test the associated suppression diode to be sure it is doing the job (I think the diodes are less than $10).

As a generic comment, it would help if people with "no-start" problems would specify if the problem is a starter that doesn't crank, a stop solenoid that doesn't engage (should hear a distinct click when key switched to ON), or glow plugs not getting power (you need a volt meter for this). Alternatively, just a complete description of the symptoms should help diagnosis.

 

[Coyote machine]

Adding to what Scott said about causes of poor starting and associated electrical connections, I want to add that MANY problems in tractor electrical systems, and some Kiotis in particular, stem from poor quality grounds, and sometimes bad/corroded (INTERNALLY), ground cables from the negative side of the battery to the frame bolt at the cable's end.
Solution: clean both battery posts thoroughly and their associated cable ends. Use the felt washers under the cable ends and use a battery post spray to protect the entire post and end from corroding. Do the same at the frame bolt, completely covering the bolt head and cable end after cleaning the end and using copper antiseize where the bolt attaches to the frame.
To test a possibly defective ground wire cable look at each end to see if there is corrosion where the wires end and if necessary and corrosion is sen cut away a small section of the sheathing to look for further creep of corrosion along the cable. OR one can try moving the cable while someone else is turning the key switch to crank to see if there is any effect on starting. This can also be done with the cable disconnected at both ends while using a VOM to test resistance and possible open circuit when cable is moved.

 

[Fuggley]

Adding to what Scott said about causes of poor starting and associated electrical connections, I want to add that MANY problems in tractor electrical systems, and some Kiotis in particular, stem from poor quality grounds, and sometimes bad/corroded (INTERNALLY), ground cables from the negative side of the battery to the frame bolt at the cable's end........

I can vouch for this. The negative ground cable on my tractor was green to the core.... caused me a lot of intermittent problems until I replaced it per CM's recommendations.
Question: what is the correct gauge replacement battery cable? I used 4 gauge.... hasn't burnt up on me yet

 

[Coyote machine]

Good question! I don't know the specific gauge offhand, but an automotive store may have a guide for gauge based on cable length and battery size/amps, etc. Or, one can take the old cable to the store and match it, or cut the old one and measure it.

 

[candosmithsmith]

Anyone know of a Scamatic for a Kioti cs 2410 tractor

 

[Everhard]

My DK40SE HST has had problems with intermittent starting for quite some time. My dealer supplied a new key switch that solved the problem the first time. The problem returned recently and I found that the start relay was not supplying current to the starter pull coil. I disassembled the relay and found the contact points burned. I burnished them with emery cloth and the problem was solved. I wonder if this relay is not responsible for many of the starting problems mentioned on this forum.

This particular tractor has two identical relays (blue) mounted on the firewall. To determine if the start relay was faulty, I simply switched the two relays, in place, and found that it started just fine. The relays are sealed, but with a soft material that is easy to remove. Pry off the cover and the relay mechanism is accessible. Reseal with any soft sealer.

Also, the start relay was incorrectly identified in the shop manual. Manually trace the starter pull coil wire from the starter back to the relay to identify the correct one.

I strongly advise you to look at the plug that the relay(s) connect to. I had the exact same problem - tractor suddenly became hard to start when cold, replaced relay, everything was fine, then next day not... Changed relay, all good, then not... Tested the relays, all good, swapped them, sometimes it worked... Anyway long story short after noticing one of the relay's looked like the plastic had burned at bit at the base of one of the legs I looked at the plug that the relay's connect to - found that the leg which showed the burning the female end on the plug the connection there which is supposed to press against the leg of the relay was not actually "springing" or pressing properly to the relay leg and was the source of all my issues. I cleaned up that connection and made sure it would make a good contact and no problem since. (This was a month or so ago.) I'm going to replace the plug at some point but haven't had the time to do that as of yet.

Pain in the ass that was! Last thing I'd normally think to check was that stupid plug - you'd never think that part could malfunction...

E.

 

[Coyote machine]

I strongly advise you to look at the plug that the relay(s) connect to. I had the exact same problem - tractor suddenly became hard to start when cold, replaced relay, everything was fine, then next day not... Changed relay, all good, then not... Tested the relays, all good, swapped them, sometimes it worked... Anyway long story short after noticing one of the relay's looked like the plastic had burned at bit at the base of one of the legs I looked at the plug that the relay's connect to - found that the leg which showed the burning the female end on the plug the connection there which is supposed to press against the leg of the relay was not actually "springing" or pressing properly to the relay leg and was the source of all my issues. I cleaned up that connection and made sure it would make a good contact and no problem since. (This was a month or so ago.) I'm going to replace the plug at some point but haven't had the time to do that as of yet.

Pain in the ass that was! Last thing I'd normally think to check was that stupid plug - you'd never think that part could malfunction...

E.

Agreed
Clearly there have been start issues over the years; and the 2 relays, since they are interchangeable, have often solved intermittent start problems. HOWEVER, not all start issues, as described above, are as simple as swapping relays.
Clean connections, burnt or bent pins and loose female pin sockets, can all be sources of failure.
So, schematics can be useful, but first line of defense is, IMHO, a through visual inspection, then further logical troubleshooting.
Good luck,
Cheers,
CM