I realised that there’s quite a lot of “common upgrades” which might be worth going through and assembling into a list for reference. Perhaps you’re thinking of doing a particular mod and perhaps this will give you an idea of how difficult it is, how expensive it is, and whether I think it’s worth doing overall.
I’ll just make a list below to begin with and then fill in the content for each mod as its own page as I get time. Leave a like or a comment if you like this idea or if there’s a mod I’ve forgotten or you think should be covered. You can sign in to comment if you have a wordpress.com account or email address.
Please bear in mind this just my *opinion* on each mod, YMMV. Nobody’s paying me to say nice things about their products so if i say I like it it’s because I like it.
Performance mods:
- EGR delete – gen1 only, negligible difference but cheap and easy to do, and every bit helps.
- Airbox mods – some prior info, I’ve left my airbox stock for now. Drilling holes in it doesn’t help and you sound like a twat. don’t.
- K+N filter – not really a noticeable difference on its own, but little improvements add up. I have one on all my vehicles inc the van.
- Performance exhaust – hell yes, but unless you have a means of adjusting fuelling, probably going to cost a little top speed. If baffled correctly for the engine CCs, and fuelling is adjusted to work with the pipe, then noticeable difference and much improved sound, I have a Danmoto Carbon GP on mine with a baffle before the silencer and a custom one in the end. It’s still loud and was faster with the baffles so they stayed. I’m very happy with the pipe, love the sound, burbles and pops beautifully.
- Exhaust baffles – well tuned baffles seem to help top speed, esp when combined with mapping to suit (PCV/TB).
- Bigger/smaller front sprocket – 13t sprocket is the cheapest acceleration upgrade on stock bikes, but top speed limited to about 74mph which gets tedious on longer journeys. In the other direction, stock/125cc bikes generally won’t enjoy a 15t but a well tuned 180cc is nice on a 15t and (if combined with rpm limit adjustments) gives you a max speed in the early 90s and 89mph without RPM limit adjustments.
- Manual/late-model timing chain tensioner – guide , my conclusion was that when building an engine I use the gen2 ratchet type, but if you have the gen1 screw-plunger type that’s fine too and I wouldn’t really mess with it. Manual tensioner ftw if you want to damage your engine and love anxiety.
- Double bubble screen – seemed to add about 3mph to my top speed on my 180cc, unexpectedly useful and recommended.
- Aftermarket ECU – Power Commander V or Tuneboss, hell yes, required if doing a cc upgrade, combine it with a dyno session or an autotune for PCV (TB has this functionality built in) and that’s where you get the results and tie all the mods together. Crucial if you actually want to go faster.
- “Auto tune” modules – I very much like the Dynojet/PCV autotune module, fit and forget. The Tuneboss has the autotune functionality built into the ECU but you need to supply a wideband O2 sensor with a matched display (the matched display is important since the TB needs calibrating to the sensor. I’ll be doing a video on this when I get the TB stuff onto my 180cc).
- Big bore kit 180cc – now on my second 180cc engine and i think overall, yes 180cc is great *if you do it right* (like build #2, not so much #1). Unfortunately doing it right is very laborious indeed, and simping on stuff like making sure the engine is balanced right, will likely leave you unimpressed. It also changes the license needed to ride and insure and that’s actually quite expensive. So yes, I love my 180cc and it goes like stink but at a cost. If I had a 125cc and only a CBT I would very much look towards raising the RPM limit along with making the 125cc perform better (cam, ECU, maybe a fancy head) and *get it properly mapped on a dyno* . Raising the RPM limit literally just gives you more top speed, exactly when you want it (when you’d have normally run ot of top speed)..”oh, nice, thank you that’s just what I wanted, when I wanted it”….rather than having to start a whole new learning-curve/rabbit-hole building a 180+. Currently my interest is to see what I can squeeze out of a 125cc+higher rpm.
- Higher RPM limit – This can be achieved by re-flashing the OEM ecu (gen1 only) or via an aftermarket ECU. PCV does not give you a higher RPM limit but Tuneboss and apparently powertronic do. You can run a PCV with a flashed OEN ecu which has a higher RPM limit, that’s what I have on my 180cc currently, and it revs to 11,500 on the stock head.. ymmv, depending on engine state. I worked my way up to that rpm cautiously (don’t just yolo it to max!) and the engine seemed happy, so i pushed a litte more. I’ve been running it like that with no mercy and even a spot of drag racing for over a year now and I expected problems but it’s been surprisingly fine. The engine does feel everso slightly different at that point and my gut tells me to not pushit any further. I get the feeling bad things would happen very quickly and expensively. Each engine is different though and mistakes are very expensive, so proceed with much caution.
- Bigger injector (for 180cc) – needed to get over about 6-8krpm. Stock injector is fine up till then but seems to reach a point where it’s always open and still not flowing enough. I have a 160cc/min (blue collar, 10-hole) injector off aliexpress. Note: with higher flow you will lose some fuel timing precision at lower RPM so expect somewhat lumpier low-rpm running in exchange for the better top-end performance. guide
- R125 -> R15 clutch upgrade with 6-spring uprated boss – (guide) for 180cc+ or stunt builds, absolutely recommended. Quite an expensive upgrade but one of the most satisfying. No more vagueness. you drop it, she goes.
- Aftermarket adjustable rear shock – I got a Racing Boy one off motogaga for around £100-150 a few years back. It only allows adjusting stiffness and most of the settings were way too hard, but on the softest few settings it’s actually spot on. The bike felt like it came out of corners better so noticeable speed difference without power change (depends on rider, ymmv).
Usability/cosmetic:
- Adding a voltmeter – very useful, let’s you spot electrical problems before they turn into a breakdown. Saved my ass numerous times.
- Adding an extra temp gauge – guide, again, supremely useful just to see what the engine is doing. Early warning of problems/overheating.
- LED bulbs – not all MOT guys like them but improved visibility on mine. Combine that with actually sealing up the back of the reflectors properly so less light spills back to you as the rider, and you might almost be able to see slightly less badly in the dark. If you ride a lot in the dark I’d recommend LED lights on the forks. They follow where you steer and allow you to see the road surface in even the worst conditions. Email me if you need pics.
- Dual headlight mod – 3rd party guide, did this on mine, 2+ years, no issues, seems fine (using LED bulbs).
- Indicator repeaters & beeper – indicator beeper is very useful if you’re new to riding and keep forgetting to cancel your indicator. Over time the beeper trains your muscle memory and then you don’t need it anymore. Def recommended for not dying.
- Heated grips – omg yes. absolute game-changer for winter riding. However the instructions on the R&G ones would have you cut through the heating wire when trimming them to length (do not do this!), so peel back the rubber and relocate the heating wire away from the part being trimmed. Also just wiring them direct to the battery is a surefire way to end up with a flat battery every time you forget to turn them off. Wiring them directly into the ignition might well be a bit much load for the circuits. My solution is to wire them direct to the battery but have that connection controlled by an automotive relay which is linked to the ignition. That way I turn the ignition off and the heated grips go off, every time. Not a single heated-grips-related flat battery incident recorded as a result. It was some extra faffing around but totally worth it.
- Adding motox bars or clipon risers – see also, surprisingly difficult to achieve but if you must have that look or are doing a stunt build then fair enough. Motox bars will tend to limit how far you can pull the fork legs through on the top yoke which changes the geometry slightly (noticeable in riding – nicer cruising but doesn’t corner as well). better riding position if you have a back injury or prefer cruising. Stunt clipons will likely not have the fork-pull-thru geometry issue.
- Winter tyres – see also, holy shit yes 14/10 for not dying in winter or when it rains.
- Crash bungs / stunt cage – only custom ones in existence as far as I’m aware, so an expensive option but if you must have one then fair enough. I made one and ran it for ages while i was practicing wheelies and it has its advantages but likely means either cutting into or losing the boomerange panels. Good for mounting a gopro on tho 😉
