Hey guys. Long time, no post, although I've been lurking. Currently trying to help a friend replace a starter on his bobcat 743. It is a combined starter/solenoid, brand new. We have bench tested it, and the gear will thrust out, but not spin. There are only 3 terminals. 12v, ground, and exciter/start. We have connected to 12v and ground, and bridged to the s terminal, but still no spinney. Are we doing something wrong (highly possible) or is this new atarter
If you have : 1 - a large positive cable to the large terminal of the solenoid and the battery is good, 2- if you have a good ground cable going from the Starter frame on clean steel to the battery negative, 3- if you have a jumper wire going from the Solenoid terminal that has the positive cable on it to the Solenoid S - Terminal and the gear kicks out If this is what you hooked up with the jumper wire being only intermittent to the S-Terminal of the solenoid and the gear kicks out but the gear does not turn, the starter is defective somehow. Simon C
Update.......so it turns out the problem was us as suspected. What we thought was a ground terminal was in fact the live post for the starter motor - hence no spinney. Tested again with the earth to starter housing and all is good. Fitted and was still weak, so have checked and cleaned all the earths, and for good measure added another earth cable from the starter to the chassis and now we are away!
Nippondenso starters are known to get arcing and black spots on the solenoid contacts. Take the 3 small screws out of the solenoid cap being careful not to lose the spring or other parts and look for black spots and/or wear on the copper contacts on each side and also for black spots on the copper ring on the plunger. If the contacts have worn a significant groove they can be replaced. If still relatively flat you can sand the contacts as well the copper ring on the plunger. Sand paper is better than emery cloth but clean everything good before putting back together. I am in the process of also putting a relay on the starter circuit from the key to solenoid on my Kubota powered skid steer. Click click click when trying to start is a common problem with Kubota's. Google AM 107421 hard start relay. You don't need an OEM JD where the part number comes from. Several aftermarket on Amazon for around $20.
The 743 used a Delco starter.... Ed
I would have thought they'd use the more common Nippondenso like on most Kubota engines.
I don't think the Denso starters had caught on yet when the 743 was in production. Yes, I do like the Denso's. Ed
I have a ND in my track loader. Some have suggested I switch to a Delco but a guy at a good auto electric shop said the ND was a heavier duty starter and even had a larger shaft. He said save your $400. I had the starter checked out when the engine was out. It is different from the starters Kubota uses though. Biggest issue with Kubota ND starters is the contacts arcing and getting black where the starter won't engage. The relay solves the problem. Wondering it it will start after you shut it off is nerve racking. If I'm on my MX track doing some work I don't dare shut it off. Putting in new glow plugs and the relay at the same time. Much better than having to pull the starter to clean the contacts in the solenoid.
Did you end up doing the glow plugs Dave. Just curious. Simon C
Not yet. My friend had some other things to do first. I think he'll be doing them soon though.