Hello Everyone, I'm new to the forum so I'll introduce myself first. I'm a 3rd generation dairy farmer and my family has been farming this property since 1905. I grew up "helping" my dad clear land sitting on the arm of his Cat D6 9U and since then I've always been more interested to the heavy equipment than the cows but the cows pay the bills and that allows me to play. We bought an (I'm assuming) 1990 Kobelco Sk200 Acera Yutani (Grey Market) Excavator from a neighbour when he upgraded to a Hitachi 270. I have run this machine for many years as we borrowed it and also had him do work for us (and he'd let me play) so I've had quite a bit of seat time but not a lot of mechanical time. I've kept up with the oil changes and filters and greasing and I have even replace one final drive when the gears piled up but I don't have a lot of experience with diagnosis and such so I'm asking here hoping for help. Recently the auto idle has stopped working and I'm not sure where to start. It seems that the stepper motor moves when the key is turned on. I noticed that the switch to turn the function on and off wasn't making contact which I have fixed. My neighbour suggested to remove the speed sensor on the bell housing and check for a build up of dirt and grease etc which I did as he had problems with that before. I see that the sensor has a lock nut on it indicating that there is obviously an adjustment for how far away from the flywheel it should be, I was fairly careful to return it to the original spot but is there an measurement there that I can check? Is there a way to check the sensor like continuity? Non of the dash works but it hasn't in forever so if there is a code I wouldn't know what it is. Anyone have any ideas where to look next? Serial number is YN-08688. Thank you for any help.
I don't quite understand which part of the sensor you want to check
I'm just trying to get the auto idle to work again and I thought maybe there's a way to check the speed sensor and maybe there's supposed to be a certain depth that you're supposed to screw it into the bell housing for it to work properly.
Since you know that the speed sensor is broken, why not replace it directly? This kind of part is not particularly expensive. By the way, the speed sensor is broken and the symptoms can't be started. Your machine has no automatic idling or automatic idling can't be lifted. It should be that the pilot pressure sensor of the rotary motor is broken. You can take the sensor of the signal valve and install it on the pilot pressure sensor for testing.
I don't know that the speed sensor is broken. The machine used to idle back if you let go of the controls and rev back up when you started to use the hydraulics again. I'm assuming that is auto idle but perhaps I am using the wrong name. There is a switch on the dash that can turn that function it off and that switch was not making contact but I corrected that. When the key is turned on the stepper motor does move. I don't have any manual as this is an offshore machine and the dealership doesn't want anything to do with it.
Is this a helicopter cab machine?
Is this a Helicopter cab?
No, that looks like a standard Mark III machine, should be no reason why the local dealer won't help you.
It has the Mitsubishi motor and was imported into North America. Whether it's a story or not the dealership said that things don't cross over.
It looks like a SK200-3 model, equipped with a Mitsubishi 6D31T engine, the same as the Kato HD700-7.
As far as adjusting the sensor, screw it in until it contacts the gear and then back it off 1/2 turn and lock it down. I have a service manual and will check to see what it has as far as the auto idle part, Kobelco manuals of that vintage were not real helpful. They have alot of words in them that aren't in Websters dictionary, we called them Jenglish. All Kobelco MkIII models were built in Japan, it wasn't till the MkIV that they started building them in Georgia. The SK200 MkIII serial number prefix YQU was the North American version and the YNU prefix was the Japanese (grey market) version. Even though they look identical there were some differences and grey market parts can be difficult to find but they are out there. My service manual lists both the YQ and the YN prefixes on the cover.
Thank you, that's awesome! I've been looking at those online technical manuals and thinking about paying for one of them but I didn't really know what I'd be getting. I'm pretty good at repairing tractors and equipment but excavators and electronics are something new that I'm trying to learn.