@tommydog:
This is a tough one.
First off, regarding your comment, "I have also read
reports of serious engine problems on
scooters with only a few thousand miles on the clock" [emphasis mine]. I have been on this forum for about two years now, and I've only read about ONE serious engine problem -- mine -- here or anywhere else. The Internet will tend to magnify major problems, whenever they occur and with any brand.
Of course, forum members represent only some small fraction of all C 400 owners, as is the case with other motorcycle brands on their respective forums. OTOH, folks with major problems -- or, like you, with major questions -- tend to seek out such forums, to gain insight from owners willing to share, or report on, or to seek help for, problems. So I continue to think that major problems with the two C 400 variants are exceedingly rare.
In my case (
https://www.bmw-scooters.com/index....brand-new-23-c-400-gt-free-part-i-of-ii.2932/), I emphasized replacement over reimbursement when dealing with corporate BMW and my local dealership. So I did want, and got, another C 400 GT. And it cost me something like $1,200, what with the electrical farkles I had to replace, closing out a credit-union loan and getting a new one, having to undergo the break-in service again, etc. So my answer to your question: yep, I would, and kind of did, buy it again.
On the stalling front, if I let my C 400 GT warm up for a minute or so when cold, no issue. I recall that there were some problems with the C 400 X of three or four years ago even when warmed up -- under very specific circumstances, such as when coming to a stop after the CVT was in coast mode down a long hill -- but BMW made some hardware and software changes to deal with that. Now, sure, if you want to take off
right now after firing up a cold engine, you may get a stall. But that's true with a lot of bikes, and not a great idea, anyway; always a good idea to let the oil circulate a bit, and take it easy for the first few miles.
The bottom line, for me, is that I pretty much love the bike, even though it has a few shortcomings that, on occasion, infuriate me if I let my mind dwell on them.
The infuriations are the lack of cruise-control on a throttle-by-wire bike with lots of sensors and a "wonder wheel," and the lack of TPMS (and the unique placement of the Schrader valves, precluding adding a front-wheel external TPMS sensor).
And the disappointments include under-utilization of the nice TFT display, and the relative lack of storage under the seat (even with the flexcase). Also, there's a little less stretch-out leg room than on the (now-defunct) Burgman 650, for instance.
OTOH, I'm enthralled with the handling. This may not be important to you, in your commuting and other riding, but it is to me. That scoot has the most lean angle clearance of any bike I've owned, and that includes some standards (Beemer R850R and Royal Enfield Meteor 350), a couple of huge baggers/dressers (Valkyrie and Victory), and a couple of bigger scooters (Burgman 650s). And taking twisties at full-tilt, the scoot feels extremely planted:
On top of that, the single feels very smooth and very peppy to me. (And note that I know smooth -- that six-cylinder, six-carb, Valkyrie that I owned for seven years was as smooth as engines get.) In terms of pep, the owner's manual even states 86mph as a top speed, and I contend that it's really 89, per my GPS, on level ground, once the break-in period is over. And the 350 engine is 34HP, compared to the 20HP of my other 350 (the Meteor, which has a top speed of 72, and is a remarkably fun bike, if I feel like doing a sedate ride on a warm day).
And double discs up front for stopping, so that's nice, too, and a feature not found on a lot of scoots.
If you need to go faster than 89, then of course this isn't the bike for you. If 89 is okay, note that a friend of mine in California did a SaddleSore 1000 -- 1,000 miles in under 24 hours -- on his C 400 GT last year, and said that the bike can be run WFO "all day long."
And I think the bike looks great, by the way. And it seems to me that the aerodynamics of the styling may play a part in keeping the bike cleaner and more bug-free than other bikes I've owned.
So there's that.
Now, regarding cleaning the CVT, I'm aware of recent posts on that , but I'm personally not doing it. I'm not doing ANY maintenance, for that matter. At 76 years old, I decided (actually, two years ago, when I bought that first, '22, C 400 GT) that I've earned the right to not get down on the ground, not get oily, etc. I simply follow the maintenance schedule, but pay the dealership to do the work. There's no stipulation, as far as I'm aware, for me or them to inspect or clean the CVT in between scheduled maintenance intervals. So I'm not doing it, whether it's not a bad idea -- probably not a bad idea on ANY scooter, of ANY brand, for that matter -- or not.
And I have the three-year warranty to back me up (which I'm fond of pointing out eventually worked for me, and also that does not come with the no-longer-manufactured 650 models, i.e., those from Suzuki or BMW).
Having said all that, there are some other scoots you may want to look into. I don't know the details of the availability of scooters in Scotland, except that I'm sure that it's greater than what we have in the USA.
Here, you can go bigger with the Kymco AK 550, a bike I was very interested in for a year or so. Trouble is, I couldn't find one to even sit on, and then my wife "suggested" that I get the C 400 GT (after her being a passenger on a C 400 X for two week-long Edelweiss tours in Europe). The AK 550, with a bigger engine, might be more appropriate for all those miles you'll be putting on. There's a former Burgman 650 owner who has reported extensively on that forum, regarding his switch a year or so ago to the AK.
Similarly, you (but not us) can go bigger with the TMax, if you can spring for the price. I'm pretty sure that I would've owned a recent TMax TechMax if they were sold here, even given the premium price. Heck, I've been writing to Yamaha once or twice a year now for about five years, asking them to sell that version here. OTOH, if you're taking stock of fuel economy, then I'm guessing you won't feel like spending that kind of money on any TMax variant, so I guess that's out.
And the latest versions of those two bigger scoots include factory cruise-control. This might be a nice thing for you to have, if the motorway portions of your commutes are not clogged up all the time.
Or in the realm of the same size as the C 400, you can go with the Burgman 400. A tried-and-true model, with better storage than the C 400, and still being manufactured.
Or you can go smaller, with, say, the Yamaha XMax 300, and others, although that might be too small for you to feel comfortable at motorways speeds. But if not, you'll probably get good fuel mileage.
Or some other brands and models that I'm only vaguely familiar with, given the lack of models from all brands imported to North America (rightfully or wrongly, but "money talks, bullshit walks," as the saying goes, i.e., if we don't buy them, they won't come, or, like the TMax, they'll leave).
I think that that's all I got, relevant to your questions.