I'm looking at a TCII and the main thing I'm interested in it for is the fuel injection. I asked the dealer about it, and he claimed they haven't seen one in for repair. I don't know the manufacturing/design issues with using FI in smaller mower motors, but it's certainly not new technology at all. You probably can't buy a car that is less than 30 years old that doesn't have FI. It's also common on bigger outboard boat motors, I believe.
I think that FI in a mower will give more consistent throttle power, easier and more reliable starting, is supposed to provide as much as 20%-30% better fuel economy, and should be trouble free over all for longer than most carburetors will, maybe longer than the engine itself on average. Once they do fail, it's not an inexpensive or likely owner serviceable repair unless you are very good as a mechanic.
I guess the bottom line is nothing is perfect, but over all somethings are better, and I think FI is probably an improvement over carbs. I think we will eventually see FI as a standard feature on all mowers, at least the upper end ones. But I also think eventually we'll see all mowers will eventually be electric, and that could possibly happen before FI becomes common place.
Kohler has been using O2 sensors for close to 20 years starting with the CH26. the newer ones are 4 wire with heater circuit closed loop systems. I don't see a standardization of the systems right now. The best is a generac code reader for Kohler, Briggs, MTD, for retrieving the codes. But as of right now Kohler is moving to their 3rd version of the software with a new connector plug to work with the new electronic governor systems. And that system will not work with the CAN BUS system of the mower that it is one that required the mower manufacturer software. So there are two diagnostic plugs on some mowers. One for the engine and one for the mower.Just like autos manufactures first came with EFI systems which were terrible all the tech had a very steep learning curve along with the systems poor designs.
I think it mostly the learning curve of the shop techs that makes them difficult to repair. Having good service manuals at hand helps a lot when they are used (read). With my background with my personal EFI automobiles it is a little for me to understand the EFI systems on small engines. Even techs with a lifetime of experience are being thrown a curve ball on these systems as it is all new to us.
The EFI systems that I repaired have improved a lot over the last few years. I remember the first Robin/Subaru engines where EFI was a total failure and they had to convert back to carburetors. Now the last few EFI Kawasaki engines that repaired was fairly easy to diagnose the problem. Due to compactness of today's equipment especially the ATVs accessing things can be problem though.
Now the Bobcat UTV gave me a fit as it was in limp mode. Very deep in the service manual was the solution as how it the system could be placed in limp mode. Turn out to be a simple parking brake adjustment. I wasn't experienced on Bobcat system so I depending input from other techs that were just as inexperienced as myself. They were suggesting things to try but none of them were fixing the problem. I finally brought and read the service manual fully that when I found the solution. I also found a partially clogged injector. I reckon the old saying "When all else fails read the blank (service) manual." still applies.
Yes having the test equipment is very nice and on some of the equipment is nearly mandatory especially something like the Cam Am ATVs. I have manage so far to do with the diagnostic computer just by using troubleshooting skills but there will be a time that I will need it. Glad to hear they are now standardizing the systems on the small engine so an universal code reader can be used. This would make it make simpler for all of us in the field.
I just wondering when they are going start adding O2 sensors to the system as the systems I have work on so far don't have them.
Not only Stihl but Husqvarna, Kohler, Briggs, Kawasaki, Honda, Yamaha, MTD and I am sure I am missing some.Stihl has their M-tronic system and now the 500 FI saw. Unless you are a dealer good luck diagnosing problems. Many manufacturers are following the lead of Microsoft and John Deere, they own the software. There is an ongoing legal fight for the right to repair. Even if consumers win the right to repair when will scan tools ba available? At a price small shops can afford? Be careful what you ask for. You might get it.