well when theres no fuel gauge on your litre bike, and you've tuned the hell outta it, and the low fuel indicator lights up while pulling 280+, despite knowing you can still go on for 30-50ish km, it definitely isnt fun

Hello

1. That sounds about right, the factory chain(in fact most o-ring 520 in general), would hold up to 15-25k km, might be time to get the chain/sprocket set replaced. X-ring set would last longer, it cost more, but cheaper in terms of price-per-km.

2. We generally recommend a major service every 20-25k, considering all the below shares similar lifespan, you save in term of labor doing them at fixed 20-25k intervals instead of changing 1 by 1, items to be replaced on top of a general checks would be
- air filter
- fuel filter
- plugs
- coolant
- valve clearance

tbh, just get the d400, has lots of value proposition on it, despite the fact you'll have to get a b full license, its all well worth it. In my personal opinion, the D250 is sort of like a lazily dished out model to shove in between the pulsar 200 and d400.

Again, if you're really keen on the d250, gear indicator isnt much of an issue as you can just replace the gear sensor with a D400 sensor and wire up a external gear indicator

the d250 is similar to the KTM equivalent of the duke 250, runs the same engine as well... its just there to fill in that odd space.

D250 runs same platform as the 400, downsized cylinder cc. So engine weights pretty much the same, but loses 150cc.

The pulsars runs on a unique 200cc platform, engine is quite abit lighter than the 250, and it runs on single cam, which means more tangible torque. Revs up to 10-11k rpm too, pretty fun for its size.

Apart from the obvious cc difference, you dont get gear indicator, you get a "budget" version of the tank panel, you get lousier forks... well just get the d400, for the price difference its worth it.