Once you get into pulling engines to bits..where do you get all the fancy upgrades and internal bearings and whatnot?

For anythign OEM, generally a good place to start is:

Motorcyclespareparts.eu – based in Germany I thni, this site is good for pretty much every OEM part right down to the nuts and bolts. They have a min delivery fee and there’s probably also brexshit duty now too so it’s generally worth trying to get a few things together otherwise the postage is pretty steep for just a couple of bolts, but they’re generally pretty quick and reliable. I get quite a bit of stuff from here.

Motogaga.com – based in Malaysia and generally catering to the international market (so more R15 than R125), Motogaga has possibly the best selection of serious internal tuning parts. If you’re wanting close ratio gear sets, a vernier cam pulley or a forged con-rod, or fancy aftermarket rear shock, big bore kits, clutch upgrade bits..you name it they’ve got it. When looking on there for R125 stuff also search on R15 and FZ150i / vixion since many of the parts are interchangable, and the R15 is way more common out that way. The person who runs the shop can sometimes be a bit hard to get hold of but is very helpful when you get though. I think you can also talk to them on whatsapp/fb. I get bits from Motogaga now and then and have so far always been pleased with the service and the products.

SXparts.com (and their Ebay shop) – based in Indonesia The folks at SXparts helped with my R125-R15 clutch upgrade by making up special kits of all the OEM components I’d need to complete my upgrade. So whilst I’ve only used them the once they were super helpful and would recommend them without hesitation. Again, lots of OEM internal engine bits (also R15 oem bits which we can’t get in the UK) and upgrade bits.

Maximumracingconcept.com – I’ve not ordered from here yet but this is another treasure trove of internal spares and tuning bits. Not so wide a selection as motogaga but some slightly more specialist bits. e.g. full set of engine bearings, larger throttle body, new head with bigger valves. Also based in Malaysia (i think) so once again catering primarily to international market, so search on R15 as well as R125

CMSNL – hadn’t heard of this place till recently but seems to have great range of stuff and decent prices including hard-to-find items like the old style lower timing gear, as well as the new style one.

ATVEng.com – yamaha & compatible bearings, awaiting first order but looks promising so far, so let’s see 🙂

PLEASE NOTE: If you’re ordering from any of these places from the UK, you will likely have import duty to pay which could be up to 20% of the value of the order, so please don’t forget to allow for that.