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Jinma 200 Tractor King ( sold by Rural King) . Warm weather stater engagement fine, cold weather starter would spin but starter drive would not engage flywheel.
The linkage from the solenoid seemed to work smoothly by hand when inspected , however I cleaned it and lubed it with a dry type of lube so there would not be any cold temperature drag. Battery current and voltage was strong at the starter solenoid. Still no engagement. Replaced with a new solenoid, still no engagement.
So I decided to drill a hole in the starter housing that would allow me to manually engage the solenoid by pushing the starter drive arm in using a rod.( think old time GM truck and cars floor starter solenoids). Still no engagement of drive gear but starter was spinning strongly as before. However this attempt did reveal to me what the problem was.
This particular starter drive has a coil spring between the sliding collar that the solenoid arm attaches to, and the starter drive gear. It turned out that the solenoid was fully engaging the linkage but only compressing the drive gear spring but not moving the gear to engage with the flywheel.
To fully engage the drive gear required two things to happen. 1. the solenoid needs to fully move the linkage and slide the drive collar towards the flywheel , it was doing this) 2. The drive gear must also ram toward the flywheel or screw up the starters threaded armature shaft at the same time to complete the engagement of the drive gear into the flywheel. This was not happening!
The fix was to remove the starter nose ( part that inserts into the bell housing) which is easily done by removing the two long Thur bolts of the starter. This allowed me to inspect clean ( the armature did not have any lube on it nor was it dirty) and lightly polish the armature shaft screw that the starter drive works on. I then lubed it only with a dry type non grease lube. I used Dry Slide some Bike-cycle shops sell it as Bike AID I have used if for years to lube motorcycle control cables, it flows in as a liquid and leaves an none grease film of lubrication.
The starter has never failed to engage since then even it zero temperature conditions. Not sure how long this will last, have not had a long term test. However I now know what the problem is and how to address it. Conclusion, even though the drive engagement would appear to work properly by hand or when bench testing ,it would hang up on the armature shaft and not advance into the flywheel in colder temperatures and when under load. The light lubing of the shaft appears to be all that was needed to overcome this borderline condition.
By the way the starter and drive did not appear to be worn and the tractor has had this problem from the first winter I used it as a new tractor.
Hope this help someone.
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I have had the same cold weather problem with spinning but not engaging the flywheel. sometimes it takes one or two turns of the key to make things happen. I have also had the problem seem to take a different tack and not sure they are related. when it is bone chilling cold for prolonged periods I turn the key to start and nothing happens. the contacts which energize the electrical system and glow plugs work on the key switch but no go with the starter. when this happened shorting the contacts on the starter always got things going. I was sure it was the key switch, but any sort of cleaning and reconnecting really did not change things. finally it dawned on me to check the clutch safety switch and eliminating it has completely solved the problem. the starter switch activates every time and I think there is less of the spinning but not engaging the flywheel issue. I would think the clutch switch is a low current situation and any contact would be enough to pick the solenoid for the starter, but interested to hear what those who know more think
thanks
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A comment on this —
I was skeptical about the need to add a relay to the starter solenoid. On most vehicles I'm familiar with the starter solenoid is a relay — in fact that's all it is. On the Chinese diesel, the solenoid also does the work of moving the starter gear into contact with the flywheel, unlike the Bendix style starters that are almost universal these days.
Moving that gear takes some current. I had my starter on the bench and I tested the solenoid with a fused power supply. I didn't have an ammeter that could handle the current of the solenoid, but a 10A and 20A fuse blew almost instantly. A 30A fuse melted slightly but didn't blow, so I would say the solenoid pulls slightly over 30 amps. The wire in the wiring harness looks to be 18 gauge, it should be 10 gauge for that current. I'll add that I doubt the switch contacts are rated for 30A, I suspect this is one of the reasons switch failures are common. The whole starting circuit is way undersized.
A relay with a 40A rating fixes this pretty quickly. Interestingly, I was looking for a socket for the relay for a neater installation, and I couldn't find a socket with anything over 14gauge wire! I guess it's not just the Chinese who have trouble sizing wire to current draw.
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I purchased one of these with a 11,000 lumen LED work light. They appear to be AWG 12.
https://www.larsenlights.com/40-amp-relay-with-socket
Account deleted.
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Maybe I am stupid/ignorant but isn't the addition of a second relay in the starting circuit essentially redundant. It seems on my system the starting device has 3 contacts. One is ground the second is a direct connection to the positive battery terminal and the third is the switched lead from the starter switch ( I have learned not to call it an ignition switch). When the starter switch is closed and that contact is energized this energizes the electromagnetic switch of the solenoid/relay attached to the starter motor which then allows the full faith and credit from the battery to energize the starter motor. Seems like once again it is a small wire used to close contacts and energize a big wire, right?
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You are correct, but that small wire is actually too small to pass sufficient current to fully energize the solenoid coil. Thus the need for the additional relay. You could just run a heavier wire all the way, but then you'd still be limited by the current capacity of the starter switch and the clutch interlock switch, neither of which are heavy enough to carry the current drw of the solenoid coil.
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Dogdoc, I used to think exactly the same thing. The issue is that in addition to closing a switch, the solenoid in the Jinma starter also does the work of moving the gear into the engaged position on the flywheel. Surprisingly, this is a considerable amount of work — it draws 30 amps when doing so, which is 360 watts, or about half a horsepower. The wiring in the tractor just isn't up to this.
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UPDATE TO MY FEB. 8TH POST
The dry lube on the starter armature shaft did seem to solve the problem, however the problem resurfaced again even in warm weather and applying the dry lube no longer worked.
I removed the rectangular cover on the bell housing, the one with the four large bolts on the starter side. Using a small mirror and good lighting one can actually see the end of the starter drive as it engages the flywheel. I had my wife engage the starter while I viewed the starter drive and flywheel. As is typical with this problem at times the starter will work fine and other times it just spins and not turn the flywheel. I could now clearly see the problem. The starter drive was always fully engaging the flywheel teeth 100% of the time even when the starter was just spinning and not turning the flywheel. It was the one way clutch in the starter drive that was slipping, not a problem with the gear teeth not engaging as I had formerly thought. A new starter drive gear ($35) solved the problem.
I opened up the defective clutch on the old drive gear by cutting off the outer band that is around the clutch to find the problem. This type of one way clutch use several roller that ram up and clinch and hold the drive teeth of the clutch. These rollers are aided by small accordion style springs that push against the rollers. These springs had lost their tension and collapsed and were not doing their job of assisting engagement. I suppose in most cases a really good spin of the starter overcame this weakness and the rotational force alone will engage the clutch. So if you have this problem you might consider checking the starter drive by viewing through opening in the bell housing before buying the more expensive solenoid.
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