Hi from New Zealand. My Kobelco SK30ur starter won't spin. This has happened suddenly, without any prior issues. I haven't had this machine long and I'm still learning my way around. Firstly i'm assuming the motor is a Yanmar 3TNE84 (how do I confirm this, where are the numbers?). The fundamental problem i'm having is that access is so damned tight I can see very little of what I'd dearly like to see. I can barely see the starter, I simply cannot see the solenoid, nor the battery leads to even begin to check those basics. (yes the battery is charged, yes the battery end of the leads are all tight etc) Here's what I can find...Under the seat is a solenoid that does go 'clunk' when I turn the key to start, but that definitely is not the starter solenoid, there are no heavy leads coming to or from it. What is it? I can just reach down and feel the starter casing, I can feel a 'clunk' there too, but no sign of life. I cannot see, or feel a starter solenoid down there, nor can I see where i might remove stuff to gain access. I really DO NOT want to remove crap without a steer in the right direction as to which approach to take...from under the seat? from the radiator end of town?? Is the starter known to fail without warning on these?
Motor ID plate is on top of valve cover on yanmar engines. Starter definitely has solenoid.
On my Takeuchi machines, the cab tilts forward. On my yanmar machines, panels behind the seat are removed for access. I've got 10k hour yanmars with original starter. I've also changed starters on yanmars with 3k hours.
Thanks heymccall. This is a ROPS machine, no cab. What panels there are are very small and don't give any obvious access, I wish it were that easy! That exploded diagram doesn't correspond exactly with my (limited) observation...yours seems to show something on the back of the starter, mine certainly doesn't have that.
I just checked, yes the engine ID plate is there, but absolutely no way to see it, it's tucked up close under the frame. Here's a photo of what I can see, that's the base of the main boom on the right. If you look REALLY hard the back of the starter is there below the alternator and under the exhaust manifold. groan!
I don't like the look of that at all! I hope that's a last resort. I'd like to troubleshoot what I can prior. The solenoid under the seat...I'd assume it's to activate glow plugs? But does it also activate the starter solenoid, or does the starter solenoid activate it, or does the key send a current to each independently? If i could find or see the starter solenoid I could easily test it, heck even the old spanner across the terminals trick would answer almost everything in an instant, but alas that appears to not be an option. Maybe I need an endoscope to navigate down there!
Update: I pulled the starter out today, awful job that included cutting an access under the seat, and it still was a bitch! So...heres how it works... battery HT+ goes to a post on the side of the starter. A heavy red wire goes from there to power up the key and everything else, the key fires the solenoid under the seat which, in turn sends a feed down to the starter solenoid. yep a solenoid firing another solenoid. Those feeds both take the longest route imaginable to get there and back. Why?? I hate dumb engineering. The starter solenoid doesn't incorporate a bendix gear engagement it's purely an HT contact to another short HT leat to a post on the other side of the starter to spin the starter (with inertia drive for the pinion). Grrr. It appears there's nothing wrong with the starter, but there certainly is with the ridiculous triggering schemozzle. Can anyone suggest why i shouldn't just bypass all of that and install a manual/push button starter solenoid, connected directly to the final HT post on the starter? I really can't justify replacing the whole thing without good reason. Just as an aside, I ponder the plethora of wires in this machine and really wonder what any of them do? Given everything is hydraulic and diesel, what use are electrics? Fuel gauge, water temp, oil pressure, glow plugs, fuel cut-off. What else does it need??
Is it a Denso starter? Ed
Nothing written on it, but here's a photo of it. This is it actually upside down, but it shows the solenoid better that way. What I'm proposing is to run a cable directly to the post the blue lead is currently on. Thus bypassing the internals completely.
Looks like it could be a Nippon Denso or very similar. Stand the starter up and take out the 3 small screws on the solenoid. There is a plunger and shaft with a spring. You'll probably see the problem right away. Take the shaft with the plunger out and replace (if has a big groove) or clean (with sand paper) the copper contacts on each side of the solenoid where the cables are hooked up . I also sand the round copper ring on the plunger. The dual solenoids are supposed to help prevent the arcing of the contacts but it is a common problem on ND starters. I had it happen shortly after getting a starter rebuilt. Thankfully mine is in a skid steer and not too hard to get to. Still a PIA though when you shut the machine off and it won't turn over.
Yeah I've already had a look in there. I think I'm going to bypass it all anyway. The original setup is vastly over complicated and the wires follow such a convoluted path. Given the environment of heat, vibration & contamination that they operate under, its asking the impossible for every connection and wire to maintain full conductivity. If access wasn't a complete nightmare I might be able to live with it, but it IS a nightmare. I'm going to set up an old-fashioned solenoid with the short wire runs (less than the length of my forearm, vs best part of 2 meters!) that Kobelco should have done to start with. If anything gives trouble in future, it will all be readily to hand to repair.
After fixing the bendix and copper plate on out kobelco(case cx36) the starter motor failed a month later so I just bought a new whole starter from these guys and yes it was a biotch to get out. Slightly different than your starter but these guys have lots of hard to find stuff. just make sure you confirm it will fit! and has the right pinion and spins the right direction. https://www.ebay.com/itm/STARTER-FI...635916?hash=item5d8a52ba0c:g:ItMAAOSwtgNd0rBm
That's an aftermarket Nippon Denso starter.
Hi....from the portrayal above it seems like the issue might be something like what is displayed in the image underneath. Simply under the middle fitting you'll see that four of the teeth on the starter ring gear have been broken off and if the motor doesn't turn over before it hits that part, or on the other hand if the motor stops where that segment lines up with the starter drive (which happens more frequently than would be assumed), the motor will not begin.
Probably figured something out a year and a half ago.