Kohler EFI engine electrical problem after jump-start

[POD]

I have a Cub Cadet mower with the Kohler V-twin EFI engine, 27hp; I needed to move my old Kubota mower the other day to move my wood splitter and it had a flat battery so I jump-started the Kubota off the new mower, did this without the new mower running. When I had finished splitting wood, the Kubota needed jump-starting again so I brought the Cub Cadet alongside and again jump-started the Kubota off it, but this time with the Kohler engine running. As soon as I hit the starter on the Kubota, the new mower gave a hesitation and then began to run roughly and blow smoke. It continues to do this. I mowed the next day with the new mower, it seems to have plenty of power but is definitely NQR, especially when cold, starts fine but runs rough and rich.
Can anyone suggest what I have most likely blown up on the Kohler EFI system? Is there a way to run diagnostics on this like OBD2? It's still under warranty- has not even had a first service yet- but warranty is obviously not going to cover something that I have damaged and I can't afford to have it out of action at the height of mowing season.

[Gav 110]

Maybe just a coincidence?

If anything I would have thought the Cadet would have stalled and not started again

I’d read the manual supplied and see if it mentioned anything about jump starting other vehicles, if not take it back, let them know that you had used it to jumpstart another vehicle and claim warranty

I’ve always been told to put some load on the vehicle supplying the jumper (headlights turned on) to take any “spike” in the power

If there’s nothing about jump starting in the manual then you are good for a warranty claim

[emoji481][emoji481][emoji481]

Gav

[POD]

Not a coincidence I think, it definitely reacted to the load of the jump start and has run poorly since that moment. I mowed with it yesterday afternoon and it is severely lacking in power so perhaps has blown a coil on one cylinder or similar.
I had a read of the operator's manual and there is a section on jump-starting the machine itself but it is silent about jumping another machine. Taking it in to the dealer this morning, will see how we go.

[Homestar]

Does the seller need to know why it started running rough? I’d just tell then it happened while mowing - perfect one minute, rough and gutless the next. See what they say - they may know straight up what’s wrong and sort it for you. I wouldn’t have thought jump starting something from it should have caused it any issues so IMO it is still a legitimate warranty claim.

[Gav 110]

Does the seller need to know why it started running rough? I’d just tell then it happened while mowing - perfect one minute, rough and gutless the next. See what they say - they may know straight up what’s wrong and sort it for you. I wouldn’t have thought jump starting something from it should have caused it any issues so IMO it is still a legitimate warranty claim.

No need to not tell the seller.
I can’t see an issue with jump starting from it either.
If there is no warning in the instruction manual then it is a legitimate warranty claim as you mentioned, but as the seller, maybe they might find it’s an issue and to add a warning to the manual or machine.

I suppose if the seller was an arrogant arse hole, then it may take a while to get your warranty claim sorted, so maybe a bit of discretion in what you do and don’t say could be of benefit to yourself [emoji848][emoji848]
Any genuine seller (really only a re-seller) would sort it out and claim there compensation from the manufacturer for parts and labour

[emoji481][emoji481][emoji481]
Gav

[POD]

I washed it down, put it on the trailer and took it in to them this morning. The mechanic whipped it around their yard and confirmed that it is running rough and feels gutless. He asked me if I noticed anything in particular just before it started doing this and I told him it started immediately after I jump-started my other mower off it. No comments either way regarding warranty but if they bill me for a repair I will enter into discussions then. The thing cost a bomb only 7 months ago. One concern is that I can't afford to leave it with them for weeks whilst we argue over who pays- my lawn will look like a paddock of silage within a fortnight at this time of year. I'd hate to have to put the old Kubota back together to start mowing again- although I enjoyed using it far more than the new one, it really was falling apart.