Tag Archives: 125cc 4-stroke tuning

Baffled – Part 3

So I found this thread which possibly explains what’s going on with my exhaust (2nd post particularly relevant).

i think this may be about gas velocity, which would sorta explain the current counter-intuitive performance improvement by adding the baffle in the can. I’ve also realised that it might be better still if i take the forward baffle out (the one which came with the exhaust system) and only have the rear one…that way i might get better performance still and regain some of the nice sound.

It may also do nothing/make it slower in which case it’s going back how it was….gonna find out today hopefully.

Continue reading Baffled – Part 3

Baffled – Part 2

I did another quick run across town just now with the baffle in and it definitely seems quicker. I dunno if that’s because I’m less conscious of the rpm and so ride differently but it definitely felt like it wanted to *go* again. Much grinning when I got home. 

I guess it’s possible that at low/mid rpm the little bit of restriction might improve torque somehow – I guess there’s sound waves and stuff going on in there to some extent like a 2-stroke. I didn’t really get chance to go flat out though and that’s where I’d expect the baffle to be a restriction…will have to see. Didn’t seem to be a problem revving high at speeds up to 50ish though, kept finding i had to back off a bit.

I’m still not loving the sound but stealth is better and obviously whatever’s quicker wins. Interested to see how it does on a test run. I guess I need to figure out some sort of timing malarkey I can work with gloves on first, though even just seeing how it performs when flat out with the baffle would be interesting. Next time she’s on the dyno I guess we’ll find out for sure but that won’t be for a while yet.

White ’08 Yamaha YZF R125

Not really sure where to start to I guess start at the beginning and will work up to date from there…

I’ve been into messing with cars for years, mostly mk2 golfs but only got into bikes sorta by accident when I fell in love with stretched scooters (they’re ridiculous, I know). Somehow along the way I got the idea that I’d quite like to do the blood bikers thing and realised that i’d need a geared bike to get a proper license in order to do so… So after some online research, concluded R125 was the way to go. A friend happened to have one sat in his garage (see pic above, as I found her he’d since got a blade and was bored with the 125) so I did my CBT and here we are…

Continue reading White ’08 Yamaha YZF R125