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Discussion Starter · #82 · (Edited)
Some pics from fitting the temp probe and other randomness...

the temp probe.. it's in what I believe is the return pipe for the radiator so whilst it's not quite as good a location for temp as the main temp sensor, I haven't got a reading from that and won't have till I have the POD-300 controller/display so this is the next best thing and should tell me if she's having a meltdown...

here's my replacement section of pipe to replace the coolant pump return..hopefully it fits in the space
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You can force it to fit exactly in the normal positions but I felt happier with the radiator a little more relaxed since it is pretty tight in there already. The bottom of the rad angled forward a little gives more room for the hose + sensor but does mean you have to adjust the holes in the fairing, but it's ok they're behind the boomerang panel so you don't even see the adjustment.

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The mount whcih came wiht the temp dial wasn't going to fit anywhere so I just made one out of ali sheet. Was going to secure it with 3 panel screws but one worked fine and less drilling in my baby's plastics..

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the temp sensor seems to assume you're fitting to a car where body = ground.. not the case here so had to include positive and negative. Easiest way to get a positive connection was this arrangement wiht a bored-out ring terminal which just fitted over the core of the sensor. Given you've got both + and - in close proximity there and don't wanna blow the fuse on the ignition which it's piggybacked off, I had to make sure the contacts were very well insulated!
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wires wires wires...always wires fs
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empty bags but back together and just back from doing a week's shopping. Rorty and naughty :)
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That rear winter tyre (IRC urban snow M+S rated) is really grippy in the dry but horrendous in the wet. Could be because of the chunky tread or maybe I need to run lower pressure but the first time out in the wet I nearly went straight in to the back of someone and I'd left plenty of room to brake and wasn't actually going like a nutter either. Have lost the back end a couple of times since in slight whiff of humidity. Sketchy AF, which is wierd bc the Heidenau K77 rear (i think that was the model) was *amazeballs* in the wet and even the frost. Still got the heidenau winter front on and nothing sticks like it :D
20200207_135334_1600a.jpg
 

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Discussion Starter · #83 ·
TFW you just got your bike sorted and wanna riiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiide for weeks but there's a goddam global pandemic wtf this is bullshit.
 

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TFW you just got your bike sorted and wanna riiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiide for weeks but there's a goddam global pandemic wtf this is poop.
Lol. The past few weeks have been wonderful. Virtually empty roads and a motorbike. What bliss! You should get a job in the supply chain for the NHS and then your classed as a 'key worker'.
 

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Discussion Starter · #85 ·
I actually used to work for the NHS driving doctors around in the night so if this had been a year ago I'd have been right out in the thick of it. unfrotunately for some reason working there meant I got shit on by everyone from my bike insurance to the little scrotes nicking stuff off my bike on christmas day while we were out helping ppl not die. Eventually as a final "fcuk you" from the machine I got auto-terminated by the system along with all other zero hours folks when a new company took over the nhs contract, which happened to be just as my friend died so I didn't have the head to sort the paperwork to fix it :(. Loved the work and the people but everything else about it sucked ass.

Tbh there'd be nobody stopping me going out now plus they'd have to catch me first, but idk - just seems like the stakes are unacceptably high now in case soemthing then goes wrong..(my partner is pretty ill so if she gets it it's probably game over, and obviously I'd rather not).

I've dug out a mountain bike so I can get back on 2 wheels a bit at least in the mean time ;)
 

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Discussion Starter · #86 · (Edited)
the R15 clutch is in at long last! no more clutch slip \o/

Crikey that was a voyage of discovery tho. Not so bad when you know how but yikes ;) Finally I can finish the video now.

As you'd expect from having 6 beefy uprated springs rather than 4 smaller ones, the clutch lever action is a *lot* stiffer, and is especially noticable as I've got a 1-finger lever for the clutch. It seems to work though and dropping the clutch now boots one the ass with no negotiation. Front wheel came up a little in second just gunning it from a slow roll which was a fun surprise. I'm still grinning from the little test trip out shopping B-)

I've left the plastics off for the moment as there's a few bits I want to tidy up, repaint and clean over the next few days. Also want to put the summer wheels on etc. Finally no more slip tho \o/.

I can't really tell if it's helped the top end or not as it was quite windy. She pulled a casual 81 on the way back which is certainly no worse than before, and there was no hesitation. Aero seemed to be my issue more than anything else. it's hard to describe but it felt a bit different.

I'm half tempted to put the oem clipons back on just to see if we can break 85 but my shoulders are already aching at the idea ;)
 

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Discussion Starter · #87 ·
So a conversation on twitter the other day got me thinking. I was describing the symptoms of the slightly lacklustre top end and their suggestion was "bigger main jet". Whilst obvs it's EFI, actually I think they might still be correct...

I wonder if the reason I'm not getting the top end yet is perhaps becuse the current injector is too small - and whilst I can increase the fuel delivery up to +250% on the power commander, that only works if there's time between firing cycles for it to stay open 250%... which I bet at 8k+ .. there ain't.

So I'm thinking that if one were to reach a point where the injector is basically just "ON", then it wouldn't matter what the number in the PCV is.. if there's only (for example) +30% time between cycles, then +30% is the most you're gonna get fuelling-wise, regardless whether you set the PCV to +250%. Also the point you'd see that come into play would be at high rpm (which is where I am seeing the issue).

So I'm considering putting the other injector I have in (blue, 10 hole, unknown cc) and see if that can inject more fuel in the same timeframe, and whether that might help reclaim the top end without having to delve into the cam and stuff just yet.

It would be a bit annoying trying to map it without the wideband but haven't had time to get that sorted yet either (the virus etch-a-sketched my work life just as I got it nice) , but I'm hoping that even if i just put the injector in and leave the map as is, it should give me enough of an idea to see whether the idea is correct or not.

I've also had a look at the cam and am not sure I can drill the hole that's needed with enough accuracy. I mean for £25 or whatever the cam cost it could still be worth a go, since I doubt my machine shop is open currently.. but idk :-\ It's just a hole but presumably it needs to be drilled exactly square on to the end of the cam so that the decomp lever ends up in the right place etc. The malossi cam comes with the hole pre-drilled but I'm also not paying £250+ for one lol.

watch this space..
 

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Discussion Starter · #89 · (Edited)
so after chatting to someone about my wideband tuning trials and tribulations, I realised they were right and I needed a differnt approach.. so I managed to snipe this little nifty auto-tune box off ebay (sorry if it was you I was bidding against!).

I figured a dyno session is about £200 and is only valid till I change soemthign in the engine...I got this box used for £118 and can use it to tune and retune as often as I like.

So basically this comes with a wideband (LSU4.7 model, not LSU 4.9 like my other one, which needs a controller), and there's a little control box which plugs into the CAN bus of the PCV, give it power and you're done. Pleasantly straightforward.

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You give it a target AFR to aim for (e.g. 13.2) and then while riding and in "learn" mode (switched from the map switch) it uses the PCV's second fuel table to produce a map of "trim values".. i.e. adjustments to your current map. After your riding session you can plug in the laptop and check the trims and apply them. The more you ride the better the trims get allegedly, and by gradually reducing the amount it can trim by, apparently you should gradually zero in on the ideal map for the bike. So you can specify a range of adjustment (e.g. +/-20%) so you can start off getting a farily rough map together, run and apply the time, then after a few runs gradually reduce the allowable trim adjustment (e.g. +/-10%, or then 5%) to limit how far out the values are. ..or something like that... still figuring out the details.

Does it work tho?

holy shit yes!

I didn't find it made much adjustment in the higher rpms (actually pictured at the bottom of the map) whcih could be because I haven't spent enough time in those "cells" of the map, or maybe the fuelling is ok there. ...but in the low-mid to upper midrange it made quite a bit of adjustment and just wow! the bike rides so much smoother out of corners. I was confused bc on one section of road I seemed to be really tanking along vs normal but the rpms seemed low and there wasn't as much pull as I'd expect, but then realised that's bc I was in a gear higher than normal for that section of road...i was going that much quicker through that whole bit :D.

The actual amount of adjustment in the map wasn't super drastic which is nice to see since that means my "hand-made" map wasn't far off the mark, but even so it just tightened everything up nicely and now when I ride I just wanna keep twisting the throttle to hear the sound and get that feeling. In my test rides I was consistently finding myself rocking up to corners way quicker than normal (and than my cornering skills could cope with)...which was a nice place to be :D

As far as I understand it the auto-tune box only works with the PCV, not the PCFC, specifically because the PCV can handle running two fuel maps at oncem and you need one of them for the trim table...so whilst you could port the maps across to a PCFC, it seems like this is an area where the PCV distinguishes itself and justifies the extra outlay (whcih is nice bc I was starting to wonder why I spent all that extra).

Very, very happy with the outcome so far. Basically more like what I was hoping to achieve with the wideband and manual tuning but probably would never have been able to get this tight with it.

If you look at the new map you can see it's adding up to 70% injector duration in places whcih is quite a lot - but this should also mean that say I wanted to switch back to the 160cc injector I should be able to pop it in, load my best-guess map up and then take it for a little rip to learn, and within a couple of rounds of learning/trimming I should have a new map set up based on actual feedback data rather than theoretical calculations.

I wasn't thinking I'd really be up for racing the bike as she was on the current engine but tbh this changes things...anyone who fancies their chances and would like a little head-to-head come and get some :D


Old and new fuel maps so you can see the sort of changes it made....

pcv_autotune_1_pre.png pcv_autotune_2_post.png
 

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Damn this makes me want to cash out and get mine adjusted. I've read up that the lurching that I get at low speeds at constant throttle is because of how lean it runs in that region and I would love to get rid of that.

> anyone who fancies their chances and would like a little head-to-head come and get some
You just wait till we're on that track C:<
 

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I wasn't thinking I'd really be up for racing the bike as she was on the current engine but tbh this changes things...anyone who fancies their chances and would like a little head-to-head come and get some
How do you think the altered riding position and brake adaptions will affect track riding?
 

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Discussion Starter · #92 ·
Damn this makes me want to cash out and get mine adjusted. I've read up that the lurching that I get at low speeds at constant throttle is because of how lean it runs in that region and I would love to get rid of that.

hmm I dunno about that but sounds plausible i guess. In general I'd been starting to think that the PCFC was a smarter buy than the PCV because it has more map slots (easier to set up A/B/C/D/Ect testing vs just A/B) and costs less, and I'd not really seen the benefit of the auto-tune, but I think this has changed my view back to the PCV. The actual mapping stage is where most of the others I speak to seem to be getting stuck (me included) and this fixes that.

Whilst one can import maps from PCV to PCFC it would always mean you're getting "secondhand" maps whcih will never be quite as good a match as a map for your exact bike... so unless we were to temporarily put a PCV on, learn the map then export to pcfc and then put the pcfc back on...idk how else it would work, but that seems like a lot of faffing about, and means a PCV needs taking off where it is now (not keen to do that) or there needs to be a spare PCV in the mix to tune with (££, though could be worth it if tuning many bikes).

> anyone who fancies their chances and would like a little head-to-head come and get some
You just wait till we're on that track C:<
haha ;) I did actually mean like a 1/8 mile but hey whatever ;) tbh it's a small track so you don't generally get over about 40 mph, even on the straight (gear low for the day if not already), it's all about hitting the corners right and being able to link them.

>> How do you think the altered riding position and brake adaptions will affect track riding?

I don't know, and this is something i'm also curious to find out. In normal riding the main change is that you can still get into a tuck and good position for cornering but you have to remember to do it yourself rather than the bars pulling you naturally into that position. idk if that makes sense?

If I'm "going for it", I need to make sure I'm leaned forward and down and remember to point towards the apex with my inside elbow which seems to put me in about the right body position, then I can lean as before and she handles just great. If you just sit relaxed and throw it into a corner expecting it to go round as before that doesn't tend to work out so well ;)

On the previous clipons I had to pull the fork tubes through a few mm more than standard and I reaaally liked how that affected the handling..so "sharp" with the nose down a little like that (surprising that just a few mm adjustment was so noticable though!). Sadly the motox bars put that back to standard since there's just not the clearance to keep it as it was but if you tuck and lean she still does ok...and for being comfortable the other 80% of riding (and lack of back/shoulder pain)...it's still worth the tradeoff for me.

The rear handbrake doesn't generally get in the way at all so shouldn't really make any difference.

Let's just hope we're not locally locked down by then as northants where I am is an "area of concern" apparently (no fucker wears masks here, so big surprise). Idk how "hot" leicester is still...
 

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Discussion Starter · #93 ·
Soo .. I'm still sorta seeing where it's going with the maps but so far I'm *really* liking that autotune box. I went for a long ride up to melton mowbray the other week and the bike felt so tight and together. Unfortunately it rained exactly at the twisty bits I went there for, and again exactly on the way home too, but I absolutely ragged the sh!t out of it the whole way back and she performed like a champ.

The autotune is adding over 100% fuel in places which makes me think perhaps it's just giving it more and more injector duration but not getting enough fuel, so it could be time to go back to the bigger injector (160cc vs 100). Last time I tried it my wideband setup packed up so I had no means of tuning the fuelling but now with the autotune it should be not just possible but even quite easy..

That said she was sounding a bit ticky the next time I went out and it's a reminder that this motor doesn't have long left. The manual chain tensioner was a band-aid/bodge to keep her running a while longer but I think it's time to start on the B motor in earnest.


I've got a friend in france who has a lovely blue R125 which I did the motox bar conversion for and we were going to do the 180 swap on his bike - he got all the bits and it was all booked for what turned out to be the first week of lockdown. He's not found anyone who'll fit the cylinder locally and is probably not going to go ahead with it now so I'm hopefully buying the cylinder off him since the place I got mine from is currently out of stock for the next few weeks. His cylinder is identical to mine, not saying it's better or worse than any other, just I've had one and it works so will stick with it.

I don't really know what's wrong with the B motor, I got told it died from being run without coolant so I'm hoping the damage is limited to the cylinder but really who knows what I'll find when I open it up.

The plan for phase 1 is simple - put the new cylinder on and fix whatever's broken in the B motor so that it runs, put a new timing chain on (just for my peace of mind) and a manual tensioner. Clean it up as best I can without engaging in ridiculous measures. Then just add the longer duration cam I've got here, put it together and see if it runs. In general it seemed in better shape than the A motor so hopefully that theme continues ;)

I'm hoping to build a basic stand/mount for the motor and I have a spare loom, ecu etc and all the bits to make it run off the bike, so hopefully that rig can function as a sort of base/testing-rig. At this stage it wouldn't really function as a dyno but would at least let me check that the B motor runs (albeit on stock/incorrect fuelling) before I have to rip the motor out of my bike. Later on this setup is where the custom ECU will be first attached and then we can test and tune ad infinitum once we get into boost and stuff.

If all seems well with the engine otherwise and it runs it'll go on the bike ASAP so I can stop worrying about the sodding timing chain letting go and making high speed valve spaghetti. That'll need breaking-in and in the mean time I can start rebuilding the A motor...which is phase 2.

That motor will get everything it needs. Hopefully by then I'll have the custom ECU set up and can figure out making the basic motor work with that, and once ithat's working ok then I think I can start mucking around with boost :)

just as a reminder (altho actually 22bhp isnt that much, pretty sure mine's around that without the turbo lol):

disclaimer: yes I know it's pointless boosting a tiny bike, I'm doing it anyway :)
 

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Discussion Starter · #94 · (Edited)
The 180cc cylinder for the "B motor" arrived today so that emans I can start rebuilding it \o/

Am planning to put a new timing chain in this motor just for peace of mind, otherwise hopefully it just needs a new cylinder, the longer duration cam, manual tensioner, adjust the valve clearances and in she goes.

I've not been able to find a reasonably priced frame for the b-motor and it's been months now. Even the insurance write-offs are hundreds, meh. So think I'm just gonna try and make something out of box section, copying the angles and swingarm bolt placement from the original R125 as far as possible but borrowing the layout a little more from the WR125 (pipe round the side rather than underneath, belly bars). It'll probably start as just an engine holder but hopefully eventually turn into an actual frame..or something. idk. super minimal tho regardless. we'll see..
 

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Discussion Starter · #95 · (Edited)
lots of updates, summarised here in pictures. Also a new top all time speed recorded on the current setup \o/ 86mph. potential for more but it was the first ride out on the new setup and it was raining pretty hard so I wasn't gonna try and stretch my luck any further.

Since I now only realy ride when I want to, and have another bike for wheelies I've put the R125 back to stock clipons, but de-flashed and mirror polished so they spark a little joy in use. LED headlights lights throughout to reduce the electrical load for the heated grips (which have their own separate ignition-triggered & fused relay, works amazing), original plastics with the old stickers removed, working towards getting them ready to paint (also deciding what to paint, probably red). Also a new double bubble screen rather than the cut down stock one. For now cage is also off, plastics back on while we see how fast she'll actually go :) (the old motox bars and cut down screen made a lot of difference to top speed).

Having tested it I can now be out on the bike in near freezing temps for a few hours at a time which is awesome. Cold hands was always the limiting factor before.

The new PCV/autotune map on the 160cc/min injector seems to be "coming in" now too.. the bike is nice and responsive, and now even seems quite happy screaming along at redline for prolonged periods. I was not merciful in testing ;)

I've still got some testing to do to find the best power AFR setting for *my* exact setup, and need to figure out how to do per-gear maps, which the PCV can do apparently, but very happy with how she's running atm... and that "nnnnyackpop" sound at the top of the gear. [chefs kiss]

I haven't changed the fork geometry since putting the clipons back on. The fork tubes should be pulled through a few mm more and I feel like it would benefit from that on the corners but i've changed a lot already so going to just ride it a while and get used to the current updates before pushing on.

Also after my laptop blew off the back of the bike whilst out on a datalogging intermission, I got myself a tiny little linx 8 tablet for running the PCV software. it's not very powerful at all but it was cheap and it can just about run the tuning software and means I don't need to carry my netbook along on tuning runs. Very gran turismo :)


IMG_20201227_154805.jpg IMG_20201218_143850.jpg IMG_20210102_175200.jpg IMG_20210103_124324.jpg IMG_20210102_120120.jpg IMG_20201216_160708.jpg

all the words (long version) here: https://northcust.co.uk/2021/01/06/winter-updates/
 

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Discussion Starter · #96 ·
been a while since I posted any updates here...been flat out with work so life is just work/work/work/ride, rinse and repeat atm, and the stunt-bike re-build (after my off) has also kept me busy in the workshop. That bike is back on the road now too with a brand-new custom subframe, 12-o'clock bar etc. Since wheelies etc is still a bit 'high risk' for the moment (really don't wanna be in A+E rn) I'm just dailying that bike too and getting used to it, and trying to make her less of a "tug me daddy" magnet. Still scares the sh!t out of me tho lol.

I've not really made many changes to the R125 recently... tweaked the fork geometry a bit (pulled the fork tubes thru a teeny bit more) which seemed to sort the cornering out and otherwise I've just been enjoying thrashing the absolute tits off her and refining the fuel map. She really goes rather nicely on the bigger injector and now that the fuel map has hit that sweet spot.

Hit a new top speed the other day (88mph) and she'll pull 85 on the flat no problem now \o/ (and that's with the very knackered timing chain, in "touring" mode with panniers etc). That autotune module for the PCV is friggen awesome! I'd still like to do the per-gear mapping and might see about increasing the rpm limit a little too but have had other priorities so it's not happened yet.The PCV only allows another 500rpm but that would prob take us into the early 90s already.

I'm having to work on the B-motor in earnest now as the current motor really is a bit worse for wear from years of relentless abuse and could do with rebuilding completely. B-motor will have the exact same type of 180cc cylinder, probably going to go forged con-rod now since i've decided to split the crank (rather than just replacing it and the crank + con-rod with a new stock unit), stage 2 cam and just less shagged overall which I reckon should see her capable of 90-95 mph territory with a bit of luck :D

Never thought I'd get her to "those sort of speeds but here we are. Maybe i will have to learn some self control after all ;)
 
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