Cooking Clutches – R15 clutch upgrade for YZFR125. Attempt #2

Ok wow I’ve been working on this upgrade & video for months now – so it’s great to finally get it finished.

This is my step by step journey to upgrading the clutch on my YZF-R125 to the larger, stronger one used on the YZF-R15 (international version, 150cc standard), which is then further upgraded with a clutch boss with 6 uprated springs (vs 4 standard) which claims it can hold 2x as much power as the standard R15 clutch.

This was not a straightforward journey, but that’s more because there was no documentation I could find on what was actually needed so had to trial-and-error my way through it. Hopefully if you’re thinking of doing anything similar then this might smooth that path a little.

The end result though, is that it works, there’s absolutely no clutch slip and I don’t see there being any for a while yet. The lever action is much heavier now but then I also have a 1-finger lever on it which isn’t helping, plus there’s easy-pull kits and stuff to be had if needed.

Assuming you have all the parts and tools needed, this upgrade shouldn’t really be that difficult. The only “custom” bit needed was the washer grinding to fit on the 6-spring clutch boss, and that only needed a grinder to shape it a little.

I’ve put a few hundred km on it since making this video and thus far it’s worked very well and I’m happy with the upgrade 🙂

Big shout out to Motogaga and SX Parts for their help with finding the right parts! without that I’d have been pretty much stuck. Thank you 😀

Parts needed/used:

6-spring clutch boss for R15 with uprated springs from motogaga:–kR5txlECWpQojtZlMHRf0ptkNqBmc

Clutch basket, friction plates and clutch disks from sx-parts:
contact sxparts on ebay if you need a custom parts package putting together:

Clutch parts inc retaining washer (part #21), and 2x spare clutch bolts (part #16) from MSP:

Cheapo clutch tool from ebay:

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