KTM EXC Fettling

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Tricky
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KTM EXC Fettling

Post by Tricky »

My trusty old (2003) had a new pair of tyres & tubes, chain & sprockets, oil and filters etc and a good old fettle a couple of months back, but since then it’s developed a couple of issues that need sorting, and with a pretty much clear weekend I was looking forward to having some quality garage time with the old girl- although it's just metal and plastic like all the others, have to say, of all my bikes, I’m more attached to this one than most others, just really because of the amount of time we've been together and stuff we've done.

Anyway, Issue No1 was fork seals- last but one time out a fork seal started leaking.
I'd done the usual run-around with a sealmate but it didn’t cure it this time so time for a new set of seals- it’s overdue a fork oil change anyway as it hasn’t had one for probably 8-10 years so I can’t complain.

Issue No2 was a fuel tank/tap issue- on the last couple of outings I’ve had it die once or twice when the fuel tap is on the non-reserve position even with loads of fuel in the tank, it's always come alive again by switching onto reserve so not a biggie but something's obviously not right so that needed investigating too.

And the other thing is to fix or replace the speedo- it's been inoperative for over a year now, I've checked connections etc ( most of the wiring behind the headlight is pretty bad, it's got very brittle in it's old age and there are a fair few of (my) quick and dirty bodged up connections with chocolate blocks etc so it's an obvious place to look) , but nothing obvious there and suspect it may just be the wheel sensor as the display itself still works.
I’ve got a brand new boxed cheapo chinese universal type speedo in the garage that includes a (different thread size and 3-wire instead of 2) sensor, so if the problem is the sensor, I’m going to see is I can use that, as that’ll save me the £50 or so a KTM one costs, or I might see if I can fit the whole display as well , we'll see.

So first up the fuel tank/tap problem- I slipped that tank off and the tap out and it was immediately obvious-

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The copper tube has absoloutely rotted away, I guess that’s at least in part due to ethanol based fueI- it did get very corroded a few years back when it was standing for a year, I managed to bring it back back it's obviously taken it's toll.
I gave it a blow through to clear the debris and for the moment have just crimped the end of the tube over and put it back. It means I’ll have to use reserve position all the time, but I will look to get a new tap at some point so that I have main and reserve, but it’ll do for the moment.

Next up is the fork seals.

This is where off-roaders like this are great, as there is no unnecesary tat on there and it’s literally a 5 minute job to drop the forks out and get them on the bench ( not forgetting to crack the top caps first while they are still in the yokes of course).

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The WP USDs come apart easily, with no special tools needed which is a nice change from those horrible old 1970s/80s RWU forks with the annoying methods of securing the damper rod to the lower leg- no broom handles needed or other such such hassles here, it’s literally top cap off, remove the spring and associated gubbins, remove the circlip above the seal, and the lower leg can effectively be used a slide-hammer to knock the old seal out.

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I started with the leg that had the popped seal first and as you can see from the above pic the colour , and quantity of ol in the legs was very different, not particauly surprising I guess as one was leaking heavily, and obviously pulling crap in too

This side was quite a nice colour considering how many years its been in there :)

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Once its disassembled and cleaned, in the words of Mr Haynes, “reassembly is a reversal of removal", except you really do need a seal driver of the right size (48mm in this instance) to do it properly - mines the two-part black thing in the below pic, someone knocked it up on a 3D printer for me, although I will admit in the past I have used the old seal as a seal driver and cut it off with a Dremel afterwards.

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Once the seal is in and the damper rod reassembled, it’s then time to add the new fork oil- the KTM rivet counters will tell you that you need Motrex 4w , I didn’t have that but did have Motul 5w on the shelf so that’s what has gone in.

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Rather than adding a specific quantity, the supposed correct way is to set the level , ensuring of course that you’ve fully bled it by working the damper rod up and down until there is no more gugling or air bubbles- in a clean installation, I can’t really see why adding a specific quantity as per the olden days is technically inferior, but mI have a fork oil height tool , so I did it the recommended way with that and set it the fork oil height to 120mm from the top, which equates to somewhere between 400 & 500 ml per leg in these forks.

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When that’s done, then it’s simply a matter of putting the spring back in , ensuring of course that you don’t forget the thrust washers, and then screwing the top cap back onto the damper rod, before nipping the cap back down onto the fork leg and then you’re done.

That was as far as I got yesterday before other things intervened, but both legs are back together and ready to go back in, it’s peeing down outside this morning so plan for today after my cornflakes is to sort the speedo ( and maybe even get that tail-tidy on the 890 too.... :think: )- More to follow
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Re: KTM EXC Fettling

Post by singlesman »

Always feels like a worthwhile use of your time when the oil comes out looking like that, every time I’ve done my lads crf forks it’s come out looking like new and feels like a wasted exercise!
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Re: KTM EXC Fettling

Post by Couchy »

I loved the 525 I had new in 2003 and kept a couple of years, raced it in supermoto and in a tarmac singles class. Did 4000 road miles on it too and it was geared for 110mph at Cadwell. Would have another
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Re: KTM EXC Fettling

Post by Tricky »

Blimey, 6 months since I’ve been in this thread, I thought it was only a couple of months… :eh:

Anyway, last time out on the old girl, we had a few things go awry, specifically ( and most importantly) the new fork seals started leaking, and I mean gushing.
It was suspicious it was both of them at the same time so it didn’t surprise me that the usual run-around sealmate didn’t fix them, so they needed replacing, and probably needless to say, I wasn't going to use ones from Pyramid Parts this time.

So out the forks came again- was nothing obvious on either of the seals to my old man's eyes, but they weren’t sealing so they were replaced with Showe 3L ones- not had them before but they have 3 sealing lips are supposedly low stiction and guaranteed not to leak- we shall see

Anyway, they all went in nicely with some Rock Oil 7.5w, and while I was at it I replaced the air bleed screws in the fork caps with some of these beauties :D

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Another thing that broke last time out was my wooden prop stand extension- not too surprising really, as it was only softwood- what I really need to do is turn up a nice piece of nylon bar to the exact dimensions I need, but I didn’t have any, and did have a couple of nylon pulley wheels so I’ve made do
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And while the forks were out, I finally turned my attention to the now completely dead speedo/ display.
The speedo function has been fecked for a good few years now, meaning it’s been showing 4661 miles for as long as I can remember, so I thought I’d see if I could get the no-name £15 Chinese one that I’ve had in a cupboard for years working.

It took a bit of trial and error wiring it up, as this is the wiring diagram that came with it,

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And the sensor is a lot bigger (M12 – the standard KTM one id M8)

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And mounts in this hole

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It’s a quite unusual M12 in that it’s a very fine 1.0 pitch- I have 1.5 and 1.25 taps , but not that fine in M12 so for the moment it’s installed in a slightly Heath Robinson manner using an old paddock stand bobbin and some bent tin – I’ll get a tap over the next few weeks so that I can mount it directly in the caliper bracket like standard, and neaten things up a bit, but this is how it looks currently

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but I am pleased to report after a brief test ride today, that after all these years, we now have a working speedo, hurrah! 8-)

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It fits nicely in the space, looks more at home than the original IMO- no rev-counter, fecked if I know how that’s meant to work ( I tried connecting the RPM ( I think) wire to the LT side of the coil, and wrapping it around the HT lead too when that didn’t work so feck knows, but it’s not really of any significance on this bike, and no clock, but the speedo works

Anyway- that’s it for the moment- I’m out with the boys tomorrow- including with @crust on his new one, looking forward to it :thumbup:
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Re: KTM EXC Fettling

Post by Tricky »

The day after the last time I posted in this thread poor old Crust had his mishap resulting in a broken femur only 16 miles into the ride :( ( I know it was only 16 miles as it was the first time in a good few years that I'd I had a working speedo.... ) which meant that the new speedo, or anything else for that matter, didn’t get much of a work-out on that day as a result.

Anyway, another five months have passed since that day ( and since I last updated this thread :roll: ) but I’m pleased to report that the old girl has been tip-top since, and the new speedo has been working well, albeit it’s made things a bit fiddly with gloved hands when out, for reasons I’ll explain in a minute.
On top of that minor annoyance, , since I replaced the original speedo/hour meter, I have also missed knowing the time of day without rolling my sleeve up, as the new speedo doesn't have a clock, so today I finally got off my arse and set about sorting both these aspects.

What I meant above by the new speedo making things a bit fiddly comes down to how it’s powered- it’s a basic and cheap (£15 delivered including the wheel speed sensor IIRC) generic Chinese unit, with just a single 12v power connection, which is fine for most bikes, but of course, my era EXC doesn’t have any form of ignition switch.
On my specific bike I have always had what I call my anti-theft device, which is just a tiny little 2-pole rocker switch hidden away in a place under the tank that when switched, cuts power to all the lights, horn etc, and also earths the ignition;- the trouble with the new speedo is that it doesn’t have an auto-timeout on the display like the original KTM one does, so I have to remember to flick the switch when stopping for any length of time so to not flatten the battery, and that is difficult and a little bit of a faff with gloved hands as the switch is so tiny.

So I decided to install a key-operated ignition switch in an accessible place, and here seemed to be the most suitable.

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It’s just a £6.50 generic Chinese one off eBay, so it’s definitely not increasing the security to any significant degree, but that wasn’t the aim. I’ve wired it in series with my secret little switch, so I still have that as my effective immobilizer that could stop a rode-away even if someone screwdrivered the lock.

I adapted an old fairing bracket I had laying about to provide a suitable mount for the new switch, to mount and position it alongside the new speedo by bolting my new bracket into KTM bracket that would normally mount the indicators- I ditched them off mine back in 2006.

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I ran and terminated all the wiring under the tank, and I have to say, am quite pleased with the result- it’s tucked away, and almost looks factory fit I reckon :thumbup:

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So once that was sorted, I turned my attention to the lack of a clock, solved with the addition of a £5.99 bicycle handlebar clock from Amazon and 10 sec with an Allen key- sorted!

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And for good measure, the old girl has also had a new set of rear wheel bearings, a little check-over of spoke tension, oil level, and air filter cleaned this week, so we’re all set for another day on the lanes with the boys this weekend :banana-dance:
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Re: KTM EXC Fettling

Post by Dodgy69 »

Excellent work. 👍
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Re: KTM EXC Fettling

Post by tricol »

Interesting on the sensor side of things. Looks like an IFM one (orange cap). That's the kind of stuff we manufacture and I try to sell. What size is the target? I'd have thought it was specced as an M8 for the target size. Generally speaking your on/off point is related to target size and the physical coil inside the sensor.

Don't know how come of you know all this stuff. I tried to do my lower leg service on my MTB forks before, it was a disaster :lol:
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Re: KTM EXC Fettling

Post by Tricky »

tricol wrote: Mon Jan 16, 2023 10:10 am Interesting on the sensor side of things. Looks like an IFM one (orange cap). That's the kind of stuff we manufacture and I try to sell. What size is the target? I'd have thought it was specced as an M8 for the target size. Generally speaking your on/off point is related to target size and the physical coil inside the sensor.

Don't know how come of you know all this stuff. I tried to do my lower leg service on my MTB forks before, it was a disaster :lol:
Sorry Col @tricol , only just seen this- RE the sensor, if by the target you mean what size is the magnet that is attached to the disc, then it's only approx 5mm dia, way smaller than the surface area of the sensor itself- you can see the magnet earlier in this thread in a pic above where I'm holding the sensor.
And this is the (highest quality I'm sure :D ) exact item in question
https://www.ebay.co.uk/itm/314063177064


And in other news on the old girl, had another absolutely cracking day out on the lanes on it with a couple of the gang this week-end, and a quite strange and fortunate minor mechanical failure too- the rear chain broke!

Why I say it was strange and fortunate, was that is was ~70 miles into the ride, right at the end and happened on the final ride back to the van at the end of the day, bimbling along the (tarmac) road at 50ish under next to no load when we were less than 1/2 mile from where we left the vans.

It was the split link that failed, but not, as you would think, by the retainer becoming detached, but the backplate of the link actually snapping :?

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It had been a faster than usual day for us with a good few really gnarly rocky climbs, so I was just a bit surprised that it failed where it did.
Anyway, fortunately, it didn't lock the wheel, do any damage, or cause us any hassle as I just about coasted to the van, and the chain isn't that old so after a nice new £4 DID link, she's good to go again 8-)
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Re: KTM EXC Fettling

Post by Le_Fromage_Grande »

My Husky did that to a chain, also with no damage
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Re: KTM EXC Fettling

Post by Demannu »

+1 for a (sort of) undamaged chain break
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Re: KTM EXC Fettling

Post by Taipan »

I remember riding to work down the A13 on my 650 Bros, when it suddenly overrevved. Backed off the throttle then brought it back in but it just revved? I thought my clutch had gone! It was only when I stopped and started looking at it I realised the chain was missing. I walked back up the A13 to find it and it was literally about a mile back! Breakdown bloke to me a bike place where they cleaned the chain and put a rivet link in and off I went. No damage anywhere to the bike?! It must have broke and just shot itself out the back!
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Re: KTM EXC Fettling

Post by Rockburner »

Taipan wrote: Tue Mar 07, 2023 3:52 pm I remember riding to work down the A13 on my 650 Bros, when it suddenly overrevved. Backed off the throttle then brought it back in but it just revved? I thought my clutch had gone! It was only when I stopped and started looking at it I realised the chain was missing. I walked back up the A13 to find it and it was literally about a mile back! Breakdown bloke to me a bike place where they cleaned the chain and put a rivet link in and off I went. No damage anywhere to the bike?! It must have broke and just shot itself out the back!
I saw that happen to someone (IIRC it was Gaz90) leaving Boxhill - the chain snapped, presumably somewhere on the rear sprocket and the entire length of the thing just went "up"! I watched it unfurling off the rear sprocket and disappearing into the sky. No idea where it came down. :shock:
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Re: KTM EXC Fettling

Post by KungFooBob »

I've had two chains go, Fireblade and R6.

The R6 one just snapped as I applied the throttle to pull away from a quiet junction, no damage to the bike, the chain was just sat in a pile behind the bike.

The Blade one left the bike as I was overtaking a Transit Tipper at about 80mph. No idea where it went didn't damage the bike at all.
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Re: KTM EXC Fettling

Post by Mr. Dazzle »

The chain snapped on my VFR750 as I was coming out onto a dual carriageway off a roundabout, went at about 80mph and actually overtook me! Saw it sliding up the road in front of me.

It sat in the middle of the A421 getting driven over and sorta flicked up in the air, I had visions of it getting launched up by a lorry and straight through someone's windscreen :shock: I actually ended up running out into the road to fetch it.
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Re: KTM EXC Fettling

Post by Tricky »

It’s been a while since I’ve posted anything in this thread, since I got the TE300 a few weeks back the trusty old orange bike has been unused, but I’m out agin in a couple of days time, and although the old girl is clean and had a chain and sprockets a month or two back, I haven’t changed the oil or filters in over a year so it’s due.

Unlike all the current KTM/Husky 4-stroke singles, the old RFS motors have two paper element oil-filters in addition to the sump oil screen- they still only hold 1.25 l of oil, but maybe that’s at least part of the reason that they are so reliable.

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Anyway, it’s all dead easy to get to, I just whip off the (KTM original 20 year old and made to last) sump bash plate before I do it so it doesn’t get full of oil.
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Am pleased to report that despite the oil looking dirty, there wasn’t a hint of any metallic stuff in there, not that there ever has been, but I always check as the way the gearbox gets treated , it wouldn’t surprise me if there was….

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I also popped the side panel off to clean and re-oil the air-filter, but it was in such an embarrassingly shitty state I decided to treat it to a new and freshly oiled one-

Old :o
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(what is good to see though is how nice and clean the inside of the old one was- it’s been doing it’s job eh :-) )

And the nice freshly oiled new one installed :thumbup:

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After that , I checked spoke tension, tyre pressures and filled the tank with Esso super before I chucked it in the van and that, for the moment, is as exciting as this update gets until later this week when I’ll try and update it with a TE300i comparison after Wednesday’s outing :hmmm:
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Re: KTM EXC Fettling

Post by Tricky »

Well, Wednesday’s ride was, shall we say, slightly different to the norm, and in that, if I had to sum it up in one word, I basically mean duller

None of that was due to the bike I was riding , some of it was the (all new to me) company and more specifically the bikes that they were on ( a real mixture including a 23 plate Montesa 260, CRF300 Rally, Husky 701 enduro and KTM 890 Adventure R ) but mainly it was more the lanes we rode, and the amount of roadwork to get to each of them- it was a different type of outing to my usual .
Still, I’ve done those local lanes now, so I know- all-time on the bike is good, but compared to my usual outings it was a bit flat - the bottom line is I’d far rather drive an hour ortwo to to get to plenty of good ones than bother with the Bucks/Herts ones again- aroud here, although we're out in the sticks, most of what were BOATs are now either footpath/restricted or when you get out towards Chesham/Amersham etc they've simply flattened and closed as HS2 is going through them.


But, more importantly, what of the bike and the comparison to it's new, sexier stablemate?
And the answer is the old girl was absolutely tip-top- I know some of it could be down to the “ comfy old slippers” type effect, as me and the 525 have been together so long, but even with that, it even now, some 20 years on, is still an excellent bike and stacks up very very well against bikes 15-20 years it’s junior.
What is surprising for me is just how well it compares, it really doesn’t feel as old as it is, which I guess either means they really got it right back in 2003, or that things haven’t really moved on that time, which we all know technologically they have.

Yes, I’m sure it would be different if I was faster and competing on it, where I’m pretty sure the currently relatively small perceived performance differences between the TE300 and this old girl would likely be much bigger, but for the riding I do, it doesn’t seem anywhere near as much as say the difference between a 2003 R1 and a 2023 R1 does, and the old girl is still so easily rideable but with as much go as I ever want and so much fun too.

So I guess the $64k question is if I had to choose between the 525 and the TE300, which would it be... :think:

The answer for me is that I would really struggle to choose as they are both crackers IMO, and it would sort of be like choosing between a 10 year old but good nick pair of my favourite old Brooks running shoes, or the latest Nike VaporFlys
Or to put it another way, Kylie ( or maybe even Dolly Parton depending on your preference :D ) or Rita Ora - they are a different generation but despite there being a fair few years between them, they are both very good at what they do, and arguably still both desirable too ;)

If it came to the crunch, then the 525 would win, which has suprised me.
I am, however, fortunate enough not to have to choose though, so the answer is that they are both staying and I will share myself between them depending on whether I fancy Dolly or Rita that day- might even have both some days! :lol:
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Re: KTM EXC Fettling

Post by Tricky »

Time for a little update!

The trusty old 525 hasn’t seen any action the last couple of months, being passed over for its younger sexier (the TE300i in this thread viewtopic.php?t=7862 )) sibling, and TBH I’ve been missing the old girl so it was the orange bike’s turn this weekend :D

We were out on Saturday just gone, and as I mentioned in the weather thread, the weather was indeed mixed and quite strange at times, with more mist than I’ve seen in this country for a long time, some showers of absolutely biblical proportions, but overall it wasn’t cold and the showers when they came were short, so we had a full (85ish miles) and very enjoyable day

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Last time out, two of the gang had punctures, and this trip wasn’t completely without mechanical mishaps either as one of the boys had a (nearly new supposedly top-of-the-range 24MX chain :think: ) break when we were only an hour or two into the ride.
The side plates snapped completely through a ( non-joining) link, meaning it wasn’t fixable with the tools we carry, but luckily we weren’t too far from someone’s mate’s mate, and he and his angle-grinder were at home, so one of the boys raced over there with the broken chain and 30 or so minutes later he was back and we were re-fitting the chain with a new split link, and on our way again :thumbup:

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Anyway, this thread is meant to be about my old orange bike, so how was it?
It was brilliant, as almost always usual, is the answer.
There had been a LOT of rain over the last week or two, and there were a good few rocky and chalky clay descents and ascents on our route, so I was very glad I was on the 525.
Even if I didn't think it was "it's turn" , I would have taken it in preference to the Husky on this one due to the anticipated terrain and weather, as it makes this sort of stuff so much easier, finding grip when there isn’t any, it has massive amounts of engine braking for when you want it, which an absolute boon on this sort of terrain in these sort of conditions.
And, of course, it’s got heated grips 8-)

It wasn’t all roses though- having taken the TE300 on the last few rides (with its now nicely set up for me suspension ) and really got used to it, jumping back on the 525 was an interesting contrast.
The rear shock is the original and has never been serviced, or even removed in the bike’s 20-year life, so it’s still wearing the standard OE spring, and although I’ve felt it was fine for all these years, if perhaps a bit on the soft side, it hasn't bothered me enough to change it.
Now though, in direct comparison to the TE300, it really did feel like I'd jumped on a chopper, with the rear of the bike sitting so much lower - too low most of the time.
And although the 525 is only 5-10kg heavier (6kg actually according to the spec sheets ) than the TE300, I could really feel it, the TE300 does just turn quicker and feels that bit more scalpel-like, which I’m putting down to better suspension, and perhaps weight distribution rather than weight per-se.

That’s not saying the 525 is bad, as it really isn’t, I love it the most of all my bikes and it compares brilliantly with bikes 15-20 years its junior, but getting the TE300 how I want it has made me realize that I have to do the same with this bike as far as is possible and let’s face it, after 20 years of use and zero attention, the rear shock really does deserve a rebuild, and re-spring.

So that is what it’s getting :1
If anything, the rear shock is even easier to remove than on the Husky- you just remove the bolt at each end of the shock and it slides out between the rear wheel and swingarm- you don’t have to remove anything else- a total of two bolts to remove and it’s out- cool eh!

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And once it’s on the bench, removing the spring really couldn’t be easier- same as with the Husky ( surprise surprise eh as they’re both WP shocks...) you just wind back the preload allowing the spring to drop a few mm from the top collar, drop the collar exposing the little wire clip and pull it off ( oo-err missus ) with your fingers

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And after a squirt or two of GT85 the shock is ready to package up and send off for servicing.

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I have to say, the thrifty side of me was sort of thinking why bother, as it isn’t leaking, still feels very well damped and all the adjusters work well, but the other side of it is that the oil, nitrogen, seals, and bushes etc in there are 20 years old, and am sure are getting close to being, if not already, past their best
So, what to do about the spring?
This is what WP calls one of their PDS Shocks.
It differs from the ones fitted to the current range as it's designed to not be used with a linkage, and as a result also wears a variable rate spring, to try and give a bit of the rising-spring-rate functionality that a linkage can, and typically does

Putting the PDS spring side by side with one from the TE300 ( which has a shock linkage), you can see the difference- although the springs from both bikes are the same length and diameter, they are otherwise significantly different.
The one I’ve just removed from the 525 is on the right, it’s the standard one that came with the bike new and has a variable rate of 71-90 N/mm
The one on the left is the standard one I removed from the TE300- a linear one with a 48N/mm spring rate.

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Going from recommendations in the books, I reckon the PDS7 (76-95 N/mm ) spring will enable me to get the sag in the range I need to. These springs have been discontinued by KTM /WP and seem a bit harder to get hold of, with a couple of places advertising them that I’ve tried so far saying unable to supply- the easy and cheap way would be to fit a 95(ish) N/mm linear spring, but that would remove the little bit of rising-rate functionality the progressive spring gives, making it a lot harsher and definitely be a backward step over what I currently have IMO so it’s not going to happen, I just need to look a bit harder.

Anyway, that’s it for the moment, more to follow once I find a suitable spring :obscene-drinkingcheers:
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Tricky
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Re: KTM EXC Fettling

Post by Tricky »

Well no PDS springs in sight ( in the UK anyway) and talking to one or two people more experienced and knowledgable on these older PDS-shocked KTMs meant that I changed my mind, and ended up purchasing an 85Nmm linear spring (KTech do a nice orange one specifically for this shock , which is nice :) )

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I had to put a good 15mm or so more preload on it than I was anticipating to get it to where I thought it should be so was slightly concerned that I'd gone too soft, but since then I've had a full day out on it and am very very happy- for the sort of terrain and pace I ride, and particularly when the lanes are as slippy as they are currently, it's the bike I want to be on.

So much so that this, and the fact that I really could do with more space for the recently purchased (non-muddy) latest project bike means that there isn't currently a place in my life for the old faithful's younger and undoubtedly sexier sibling, so as of yesterday the TE300i is a goner and I'm back to just the one muddy bike, my favourite one- we're next out this coming week-end, and it's going to be a bit nippy I think, but I can't wait.
She's definitely a keeper :thumbup:
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Re: KTM EXC Fettling

Post by weeksy »

Wow, top stuff. I love your bike passion and attachment, it's great to see
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Re: KTM EXC Fettling

Post by Tricky »

weeksy wrote: Wed Nov 29, 2023 9:30 pm Wow, top stuff. I love your bike passion and attachment, it's great to see
Cheers, albeit I'm pretty certain that the next project is already testing that, and I haven't even put a spanner on it yet... :think:
Am currently in the process of compiling a list of all the bits of it I need to sort and jobs that need doing to try and make it decent and something I won't be embarrassed to be seen with - it's a big list! :lol: