I'll see if I can put it all together from your post with what happened... and see if the two line up.
Initially starting and running the tractor everything seemed fine.... though it blew a lot of white smoke at an idle, a lot of white smoke at idle. Before staring, I Checked the oil, it was in the operating range but on the low end. The tractor smoked pretty good at an idle (though I thought the idle was a bit high, ~1200-1500 RPM), the Hobbs shows 1100 hours by the way.
When it ran away, I was unable to successfully shut it off by turning the key, that did nothing... keep in mind this all occured while unloading where my road meets one of the major/ and only north-south Two lane highways in Idaho, so with log trucks and 18 wheelers whizzing by, my focus was really on not getting crushed. I did shut off the fuel valve, though that was really not a factor. The tractor did go WOT, no matter what throttle position, hand or foot throttle, and would not shut off by turning off the key which is all i could think to do at the time, Prior to that moment I had never heard or seen of the Runaway Diesel phenomenon. I have a video I took... but has a lot of colorful language that probably wouldn't be good to share on a forum. The handle idle/hand throttle was never used, though when it was not running I could see that the throttle linkage for both the foot pedal and the hand throttle both appeared to be functioning fine where they connect on the injection pump. Before going WOT, it would start and shut off with the key. After going through the Runaway and shutting off on it's own, I did let it cool, added oil (as it was now showing way low on the dipstick) and it started and ran and shut off with the key a couple more times before running away a second time.
As for the price, I did get one that has a enclosed cab, and it came with a 60" snowblower... i bought this thing over the internet, having visited the dealer once prior... I will never purchase something of this or any other nature like I did, I'm not a guy to go out and buy brand new things, everything i own; chainsaws, motorcycles, trucks, cars, snowmobiles, lawnmowers, etc... all used, I've never had an issue like this, also worth mentioning I supervise and maintain a Frieghtliner M2 buisness-class wild land fire truck with Kubota 3 cylinder auxillary pump that is in it's 8th year of service with no maintenance or mechanical issues, I have been a snowcat operator for 3 winters with Mercedes, Cat, Cummins, and LMC machines also grew up on an apple orchard with Ford, Masey and Ferrari Tractors among other equipment, it's not like i jumped on this thing like Yosemite-Sam and started going balls to the wall seeing what it was capable of.... i treat machines better than myself, just sayin.
I can't take it back to the dealer as he has documented court cases against him of screwing people over, and basically told me I'm on my own as it appears to be doing this because of operator error. I operated this thing for no more than 15-20 minutes after delivery. I had thought I did quite a bit of background on this/these Iseki tractors and had heard nothing but positive things so I felt like I would be good to go on it.
I'll try and get some photos, with all that happened unloading my friend who helped me with delivery has it on his trailer still at his place... also my road washed out below the highway three days after this fiasco happened so I gotta get that fixed so I can get it to my shop to start working on it
