KX41 Excavator D1105 Still More Starter Issues

[aesmith]

I posted earlier about starter problems, but I thought I was all sorted fitting a European (WAI) starter rather than the Chinese most offer.

D1105 Starter Issues

Hi, The engine is a D1105-BH fitted to a KX41 digger rather than to a tractor, in case that makes a difference. The starter intermittantly doesn't work, the solenoid draws power but doesn't move or doesn't energise the motor for some reason. First time it did this was after a lunch break, so...

www.tractorbynet.com

However unbelievably that starter is now dying in the same way that the EBay one did. It's sluggish to turn and can barely start the motor sometimes. Here's an example, cold start and battery freshly charged (actually sometimes it's a lot worse than this) ..

Of course I checked all connections, checked the battery was charging etc. Just as a last resort I remitted the old intermittently faulty starter and did a cold start this morning. The difference is night and day ..

I really dont know where to go with this. Is there any way the machine can be killing starter motors? Or something I'm doing? I still don't know what causes the intermittent fault on the old starter, I've stripped it and tested on the bench and nothing seems wrong. So for the moment that's where I am, one lively starter that sometimes doesn't work at all, two replacements with various degrees of crappy operation, but without the intermittent problem.

Waiting to hear back from the dealer about the new WAI starter. But would welcome any comments or suggestions.

 

[rScotty]

If you haven't yet, take the solenoid apart to make sure the high amp contacts are clean - you can lightly file them if it comes apart - or simply replace the solenoid. A solenoid can click and draw power normally through it's field coil (small terminal and case), but still not be able to pass enough amperage through the heavy terminals from battery to the starter to make the starter spin.

After battery connections, A defective solenoid is probably the number one cause of "starter" problems.
It is normal to replace or repair the solenoid at least several times before the starter motor itself needs attention - and then the starter often only needs new brushes and a brush/commutator cleaning.

Always keep your old original starter - you can't buy a mass-market commercial rebuilt that is as good as that OEM starter that you rebuild yourself or have a local mechanic do for you.
Most OEM starters can be rebuilt indefinitely.

rScotty

 

[aesmith]

Thanks. On this type of starter the solenoid is integral in the main body with the actual motor piggy-backed on top and driving through reduction gears. The other way round from most pre-engaged starters where the solenoid is the bit piggy-backed on top.

I've had the starter in bits a few times and everything seems to move freely. The contacts for the actual switching part of the solenoid seem OK as well. I think if it was actually reaching those contacts you'd hear a click. What actually happens is complete silence, although the instrument lights dim showing current is being drawn. So my theory is that the solenoid is either not moving at all, or not moving far enough. But I can't work out why.

Nor can I understand why replacement starters get killed so quickly. This one is only just on six months old and the machine's really not been used much as I had to sort out some issues with cooling and fuel hoses. The Ebay replacement lasted just over a year and is actually now better than the WAI all though still not right, which is why I'm back to the original again.

By the way when I say "original" I mean originally fitted when I got the machine. It's an after market replacement itself.

 

[rScotty]

Well, it does sound like the solenoid is still a suspect - although not in the simple form I was hoping. There are a thousand variations on starters and solenoids. Most variations seem to be aimed at reducing copper content.

When I started driving, most farm vehicles didn't have starter solenoids. Getting the high amps to the started was a manual operation. A pedal on the floor that pushed a rod that physically connected the contacts necessary to pass current to rotate the starter. The ignition switch on the dash was for turning on the ignition only.

FFWD to 2020, and the dual purpose "solenoid/ignition" switch is still a source of problems. But that switch doesn't sound like your problem.

However, it is odd that your solenoid draws enough power to cause the lights to dim noticibly. .... but maybe that is a hint or could be part of the problem - because sometimes when starters are rebuilt overseas they seem to have less power. I have no proof, but have seen it enough times to make me wonder if the starter and solenoid windings were replaced with different alloy. It would be easy to do and difficult to tell.
That possibility is one of the reasons I recommend rebuilding the OEM starter.

Another place to look for unusual wear or lack of engagement is that there is an engagement gear between the starter motor and the flywheel often called the starter pinion. The pinion also incorporates a one-way clutch, and is normally not engaged. It becomes engaged either by being pushed by the solenoid, or by being flung into position via centrifugal force as the starter motor turns. In either case, it needs to travel along a shaft far enough to completely engage the flywheel. Motion of the flywheel as the engine starts disengages that gear.
rScotty

 

[ROUSTABOUT]

It may be that all the safety switches are robbing enough voltage to keep solenoid from proper activation. Have you jumped it straight from battery?

 

[aesmith]

Thanks. There's a really good auto electrical outfit in Aberdeen, but it would need a special journey, and another trip to pick it up. One option would be to get the old starter into them to see if they could find the intermittant fault because clearly im not able to find it.

I'm going to send the new one back for testing, it should be fixed or replaced under warranty.

Plan B would be leave the old one in place as it's the best, live with the risk on the basis that its pretty quick to swap if im stuck. After all i have two spare starters now.

 

[aesmith]

It may be that all the safety switches are robbing enough voltage to keep solenoid from proper activation. Have you jumped it straight from battery?

I haven't yet because the fault hasnt shown itself since i reverted to the old starter. I have test lead made up ready.

I don't know if there are any safety switches though. It's an all-hydraulic excavator so no clutch or neutral.

 

[ROUSTABOUT]

I haven't yet because the fault hasnt shown itself since i reverted to the old starter. I have test lead made up ready.

I don't know if there are any safety switches though. It's an all-hydraulic excavator so no clutch or neutral.

Does the arm have to be folded down to operate? Controls have to be in neutral to start. Seat switch? Travel switch? Surely it won't start with travel depressed. Swing? There are more switches than you think.

 

[aesmith]

Surely it won't start with travel depressed.

It will, I found that for myself.

No seat switch. There's a red lever that disables all the pilot controls, but it will still start even if that's enabled.

I'll have a quick test but I bet it will start with a control lever pulled (will need to be careful). If they'd wanted to interlock with the digging controls a single switch on the red lever would make more sense.

 

[aesmith]

I bet it will start with a control lever pulled

It does.