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Discussion Starter · #61 · (Edited)
drifting and subsequently wheelies where what got me out of really deep depression/grief and steered me away from offing myself earlier this year after my best friend died (who was also my bike mentor). Literally gave me a 'reason' to live, so yeah I guess I'm pretty focussed on "honouring" that. I realise there's other 'reasons to live' etc but depression isn't necessarily logical so you gotta go with what works.

> Or a stunt team??

literally the plan. well..not a team, a pack maybe? whatever, or solo.

I'm doing it primarily for me tho, whether anyone else is into it, appreciates it or approves (or not) I could care less ...though if something happens to come of it then great, if not also fine. The stunt scene in the uk seems pretty dead but again, whilst it would be nice to have likeminded people to ride with, I can get what I need from it riding solo.

It's obviously not the only thing I do with my bike but it IS something which matters to me, and as I've found out the hard way with the R125, daft little details like having the oil pickup in a place which doesn't cause starvation in a long wheelie (like the 03-04 636 has, but for example the sv650 does not) matter...*if* that's what I'm gonna do with the bike. If it's just for going fast then whatever.

The jury's still out on how the R125 will handle longer wheelies...I guess we'll find out once mine's run in and I've got good enough for it to be a problem ;) hopefully I'll have the oil pressure sensor rigged up by then to avoid another rebuild.

I'm not really that fussed about other stunt stuff - it's cool and I like watching it but I have no real aspirations to be like "the best stunter" or whatever. For me it's all about the drifting and wheelies and just being in_that_zone. Once I've worked out how to do that, that's pretty much what/all I plan to do, as often and for as long as I'm able to. Beyond that I don't know or have any real plans. I am kinda digging trials tho.
 

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Good on ya!

I've been in dark places before. Wendy (my wife) has made me realise that I am important and I have a purpose as well as being important in her life. The show goes on as they say.
 

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Discussion Starter · #64 ·
ok so went for a little blast up to to the next town and back which is my normal test run - 25 mins each way roughly. It was wet so was still taking it easy and I'm still not quite out of the break-in miles yet so according to the manual I shouldn't be doing "sustained operation above 8k". Still tho, got to have a little blast ;)

Main thing of note was that whilst the power band (8k+) is very nice and effective in lower gears (e.g. round town), this was the first time I'd tried anything like a top speed run (whilst still not revving too high) and there seemed to be a distinct lack of torque where normally you'd be very much in the power band (8-10).

Like I say I wasn't revving it out fully so it's not a complete picture but tbh it makes sense. I had the pipework pretty much perfectly tuned for the 125cc motor and now with 44% extra cc, the pipework is a bit small...hence the amazing low-down torque, but then runs out of flow under full load.

It could be as simple as just needing more fuel, or the baffle/s taking out of the exhaust (it was overpiped before without them so may be perfect now), and maybe doing something with the intake side too. I also have the high lift cam and bigger injector to go in which should both also make a difference.

However until I've got the wideband o2 sensor on I've got no idea what's happening with the AFR so am not going to mess with anything so that's next step.

I'm in the latter stages of building a front to my car port to turn it into a workshop which has been a mission, but will give me much better privacy, security for the bikes and perhaps mean I can find a home for the tig welder and the big argon cylinder that isn't the hallway and my office respectively. IT'll also mean I can weld in peace and quiet with less wind and weather and without worrying about accidentally blinding passers by. That's holding up progress a bit but I think it's a worthwhile detour..

I'm also trying to sort a minor issue I've discovered on the new bike but then tig welding the o2 sensor bung in on the R125 exhaust is the next thing on my list, since that opens the door to all the tuning options, and I feel like it's very close to being how I want it.

Tbh this was not a surprise - the exhaust was perfectly matched to the airflow of the 125cc motor to give it the most torque at flat out, based on much testing, so it's entirely expected that it's doing what it's doing. Also we're still on the standard injector which is running +70% duty cycle in places and may simply not be able to get enough fuel into the cylinder in the time available.

The wideband should reveal all, and once it's all dialled in I think it should be rather nice. If, by adjusting the breathing, I can push the power band back up to 8-10k it should be very sweet indeed. I love the low down torque for blasting about town but not at the expense of top speed ;)

I didn't even push the speed over 70mph so doubt I even really went past 9k but if the injector was running out of flow, WOT in top gear is the very last place I wanna be running lean so didn't risk it till I have AFR readings.

There's only about 50miles left on the break-in (600mi total) and I was planning on giving it a couple of hundred extra before I start wringing its neck properly and I definitely need the fuelling dialled in before doing that... all pretty encouraging tho overall and it still hasn't blown up so I guess I did the rebuild more or less correctly \o/
 

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Discussion Starter · #66 ·
I made it through the break-in miles at last \o/

Also finally got the wideband O2 sensor on so I can start street tuning, and now find the clutch is slipping again. Loads of power left but topping out at about 75mph :-\ I was never going at full rpm before or I'd have noticed it ages ago. First time I've run her up to 10k since the rebuild.

I guess summer of clutch-ups followed by almost double the original power was a bit much... Time for an upgrade to 6-spring R15 clutch internals :)

 

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Discussion Starter · #69 ·
in full winter trim and loaded with shopping..clutch slipping quite a lot now...however

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hopefully this will help: (6-spring clutch boss from R15 international version from malaysia).

I de-baffled the exhaust today (end baffle) and put the new map on and I'm pretty sure she's quicker again now. Not overpiped like she was before with it de-baffled. I think this might be about right and sounds rowdy :)


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Discussion Starter · #71 ·
ha yeah I don't mind that look for the winter tbh. I'm missing the fairings though.

Once this clutch and oil change stuff is sorted she's going back to full fairings for a bit. I need to repaint the crash bars anyway: winter salt has not been kind.

No car life tho..and shopping requirements.
 

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ha yeah I don't mind that look for the winter tbh. I'm missing the fairings though.

Once this clutch and oil change stuff is sorted she's going back to full fairings for a bit. I need to repaint the crash bars anyway: winter salt has not been kind.

No car life tho..and shopping requirements.
You should use ACF50 spray to protect against the Winter and salt corrosion. You can spray it on everything apart from the brakes or tyres. Bit expensive but worthwhile if your riding all year round.
 

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Discussion Starter · #74 · (Edited)
yay so after a fair amount of back and forth my latest round of clutch parts arrived so now I *should* have all the bits I need to fit an R15 clutch with uprated clutch boss + springs, which allegedly can hold 2x the power of the original R15 clutch. Apparently there's one clutch setup (potentially) stronger that this from the fz15 whcih is basically a YZ-R15 clutch but with an extra friction plate + disk, but the fancy clutch boss I got from motogaga was for an R15 so I stuck with that for the moment. The R15 clutch only has 3 clutch plates & 4 friction disks vs the R125's 5 of each but they're a far bit bigger.

The clutch springs are also noticably wider (won't fit in the R125 clutch boss holes) so it all looks a fair bit beefier than the original R125 setup :)

Assuming the priary driven gear is the same size and fits (looks like it should) and assuming I haven't missed out any parts then we might be in business and that should hopefully put paid to the clutch slip I'm experiencing at the moment.

If it works out then the seller is happy to ship more of these complete R15 clutch kits from indonesia if anyone else needs them.

FWIW motogaga were precisely ZERO help with this process thoughthe bits did arrive pretty quickly from them, just don't expect any support. this info all came from the ebay seller I got this round of bits from.

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Have you stopped and thought what the cost would have been to simply buy a more suitable bike for your stunting purpose instead of transforming a basic 125cc?

What is your modding cost to date (if you don't mind me asking)?
 

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Discussion Starter · #76 ·
>> Have you stopped and thought what the cost would have been to simply buy a more suitable bike for your stunting purpose instead of transforming a basic 125cc?

yes, hence bought a bike specifically designed for stunting. Half the weight, twice the power - still under wraps till I've got her road legal tho ;). Literally designed to be jumped and wheelied (and dropped), and I have much more limited emotional attachment to it.

This isn't about that though. I've not been able to wheelie practice that since doing the engine upgrade - first was running in then clutch issues. The clutch slip i'm getting now is during normal riding (well, flat out..which is normal ;)). I guess you put 2x the original power through the drivetrain and it might slip a bit ¯\_(ツ)_/¯

>> What is your modding cost to date (if you don't mind me asking)?

I haven't really kept track of it tbh but it's not been terribly expensive - especially compared to doing literally anything on my last car so I'm not complaining. The R15 clutch kit was about $140 inc shipping, pls the R15 boss from motogaga for about $50. It's all pretty modest sums and stuff like the stunt cage etc cost peanuts cos i mostly made it out of pipe and bits I had lying around.

I get a lot of entertainment value from the building/tinkering side and that's also easier to do on a cheap little single cylinder. I've considered other bikes (e.g. R6) but I don't really want the complexity of looking after an i4 motor yet...a twin might be better (e.g. MT07) but I'm not really into nakeds, especially for doing distance in weather. I like the idea of a Tenere 600 or similar maybe but when I sat on one at the yam dealership it seemed like the size & weight of a small horse and just seemed like too much bulk for me to deal with.

So I keep coming back to just sticking with the R125. I just like it plus I already have it.. and once I've got the clutch slip issues ironed out it'll be pretty much were I want it to be :)
 

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All the people I've known who have put 180cc kit on the R125 have all experienced clutch or gearbox issues.

I understand completely where you're coming from regards the building or tinkering front. Must admit I look forward to a weekend spent in the garage working on one of the bikes. I even find washing them relaxing, especially after a tough work week.
 

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Discussion Starter · #78 ·
>> All the people I've known who have put 180cc kit on the R125 have all experienced clutch or gearbox issues.

understandable...but there are 180s out there working so I guess it's just something you have to work through..

>> I understand completely where you're coming from regards the building or tinkering front. Must admit I look forward to a weekend spent in the garage working on one of the bikes. I even find washing them relaxing, especially after a tough work week.

yeah doesn't really matter what it is - just time in the workshop tinkering with bikes ftw. Fortunately there's enough bikes that something always needs doing ;)
 

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Discussion Starter · #79 · (Edited)
had some work changes going on so been havign to deal with that lately.. so not really had time to post about stuff, just do it..

Nearly 1k miles on the new cylinder and I'd been feeling with the old baffle in it was too restricted and losing power, and without any it's still a bit overpiped and was losing the torque at the top end.

So I got some 2.5" ali bar off ebay and cut a slice off and then made up some sort of baffle on the lathe, which looked more like the sort of diameter I was thinking might be good. One side is a bit tapered bc I was limited with the lathe bits I had, not really done much boring before, new bits on order will bring new possibilities.

Either way I had it tapered side out and performance was great but horrible clacky, farty sound. Just tested it the other way around today (flat side out) and performance is even better and sound much improved and pretty much perfect. You can go really quiet if you need to stay low profile, but when on it properly she makes all the right noises. Not as many pops and bangs as de-baffled but enough ;)

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so just been out for a wicked test ride today - ~30 mins each way, country roads, town and fast 3-lane a-roads too, and she absolutely aced the lot. A-roads are now actually kinda fun. Keeping up with traffic wasn't a problem at all and she pulled 82 into a strong wind before running out of road again, and that was with a large, flat protruding rucksack on me too, and with the motox bars and cut down screen which are a real hit to the aero.

On standard clipons, without the cut-down screen, without the backpack/sail and in full tuck I reckon 85mph and beyond would be actually fine, and probably pretty terrifying B-)

We weren't out of revs either - obviously I was focussed on where I was going but I think we were around 9k so plenty more headroom and she was bang in the the "surge"/torque, which seems to come in around 7k and last till just shy of 10k since the new baffle. She definitely pulled all the way to 10.5 one time too so it doesn't seem to drop off now like it did before.

It's hard to explain just how happy I am about how she rides now. It's like running with an excited puppy. Still a puppy but hella fun and up for anything. Keeping up with traffic on an a-road wasn't a problem, I actually quite enjoyed the fast section, wouldn't mind a bit more of that. A showdown with literally any bigger bike will not go my way but so what lol.

I need to set up an alternate map since atm I'm just on the one from the wideband, and I thnk the 0% throttle might need to be a bit leaner (big of bogging when you crack the throttle) and i'd like an alternative fuelling (e.g. +/- 10%) for flat out too and see if anything changes there esp now with what's probably over-scavenging aka "the surge". The top end could still be a bit stronger but I think the piston is also still loosening up to higher rpm so not looking to rush it, and given we haven't changed the throttle body, intake or valves I reckon she's doing bloody amazing :D
 

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It's hard to explain just how happy I am about how she rides now. It's like running with an excited puppy. Still a puppy but hella fun and up for anything. Keeping up with traffic on an a-road wasn't a problem, I actually quite enjoyed the fast section, wouldn't mind a bit more of that. A showdown with literally any bigger bike will not go my way but so what lol.
You are excited and the bike is enthusiastic?
 
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