spinning but not ENGAGING starter problem sloved

Thank you for taking the time to post this for all of us!

Excellent news. I have been using graphite lube in starter solenoids, and other locations as well, for the very same reason; it doesn't thicken with cold temperatures AND it doesn't attract and hold dust and dirt.

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

I added a relay to my starting circuit so that the solenoid gets power through a 10 gauge wire instead of the wimpy little 18 gauge wire that was OEM.  Soved all the problems.

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.

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

I grab my sockets, breakers and wire from the wrecking yard. They are usually sized right.

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? 

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.

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.

Sprag clutch has a lot of applications.