Chain Guides and Shock Guard

Started sorting the chain guides and ran into a few issues. The guides supplied by CCM are for 520 chains and as 644 models use a 525 you need to open up the front guide to make it fit properly, or just let the chain cut its own path, I went for the former using a dremel and sanding drum.

I replaced the lower chain tensioner’s plastic guide with a nylon one from Haines and the lower rear guide still thinking about its purpose, as not sure it adds any value. I fitted the new nylon part by heating it in a cup of boiling water then attached a nut and bolt to one end and gently bent it to shape, will change the nuts for nylock ones.

Once the guides were in place I rivetted the chain together and discovered another issue, the chain hits the tyre. After speaking with Anthony at Haines I adjusted the rim by offsetting it slightly to the right by attaching my dial indicator to the swingarm and loosening and tighting opposite spokes until I had clearance.

Fitted a new rubber shock guard, requires 4mm x 10mm rivets, I added some 4mm washers to the back to ensure the rivet clamped on to the holders. typically ran out of rivets, sigh!

Footpeg Pins

Finally sorted the footpeg pins, found some hollow stainless ones on eBay, they were listed as being for a KXF250.

They are a bit longer than required so I cut 5mm off the end and redrilled the split pin hole using a cobalt drill. The mounts of the frame were drilled out using a 10mm drill and then deburred and repainted then the pegs fitted with KTM springs and stainless R clips. At the same time I sandblasted the rear brake pedal and fitted a new pivot bearing.

Finally result is much better than the rubbish CCM nut and bolt arrangement.

Fuel Tank

Started by cleaning the tank using brake cleaner to remove the old graphic’s marks then polished it using a soft polishing mop and compound mounted on a drill. Then I stripped and rebuilt the fuel tap.

Wiring Loom 6

Finished the loom, went to start the bike and got caught out by the elusive hidden resistor. I’d heard about the resistor, but also saw posts saying it wasn’t fitted to all looms, so as I couldn’t findone when stripping the loom carried on building the loom and then couldn’t start the bike.

Decided to check through the old loom and in one group of cables that I didn’t unwrap as they were all black was a broken 100 ohm resistor. If the ECU doesn’t see that resistance on the 6 pin connector’s black wire (pin 6) then it won’t start.

Unwrapped a section of loom and added a resistor, bike started first push of the starter, didn’t run if for any longer than I needed to test the rev counter which is fed by the white/blue cable from the ECU’s 6 pin connector pin 4 . I also had to add a permanent 12v from the battery for the dash, so again unwrapped the loom and fitted the wire and rewrapped the loom, AGAIN!

Once all the circuits were tested, I depinned connectors so that I could make the cable runs as short as possible to tidy the loom up.

I bought some 3M cable clips to hold wires in place under the rear mudguard.

The final thing I did was trim the top of the airbox off using a Dremel, so that cables could run between it and the subframe, there’s a natural line on the moulding to trim along where the top sticks up about 6mm.

Rear Mudguard

Didn’t like how the rear muguard fitted and I’d drilled the holes for the indicators in the wrong place, so bought a new mudguard (UFO YZ125-250 98-02) and did it again, properly.

I ‘eyeballed’ the cut like last time, but did make note of the cutting dimensions and indicator hole positions so anyone can repeat this with minimal grief. Once cut I held the mudguard in place with tape to get the positions for the side bolts then drilled the holes for the rear light mount.

and then I sighed some more!

Posts have been a bit limited lately, as I’m dealing with some ‘script kiddy’ who’s trying to hack my site, why you’d want to hack a site about my bike projects fuck knows!

Work has progressed and I’ll do a stack of updates soon.

Shock Bearing

The shock bearing isn’t something you can pick up from a bearing shop, as its 25 x 15 x 12mm.

You can buy a KTM 65 sx or 640 LC4 bearing- K50180005 or search BUSHING KGW 1525 HD its fitted to many KTM models, currrently around £26 each , All Balls Racing kit – 29-5059 £22 each. However the KTM and All Balls seals are different to the CCM ones, the bearing bushes have the right bore (12mm) but are shorter, sigh! or eBay seller – bialko108 is selling a kit for £12.

I bought a KTM 65SX All Balls kit, as a starting point, and am waiting for the eBay kit. I didn’t realise the shock bushes in the 65SX kit are 10mm bore, so always go for the 250exc kit if you need bushes, I’ll work out what extra spacing is required once the eBay kit arrives.

If your bushes are fine then go for the cheapest option and maintain your shock, if the bearings seize there’s a good chance leverage will snap the shock end off!!

Well disappointingly the bearing from eBay never arrived, so as a temp fix I fitted the 65sx one and drilled out the bushes.

Shock Rebuild

Appears I missed this whole section out, probably due to the pandemic kicking in. So as mentioned previous when I took the spring off the shock it proceeded to dump its oil and gas, sigh.

As with everything else on the bime it was covered in road debris and was in need of a full rebuild. This is a bit tricky as CCM didn’t provide any info on the shock, so after hours looking at paerts diagrams I decided the closest match is either a KTM 640LC shock or KTM 65, both use many identifcal parts to the CCM. This meant getting parts would be easier than expected.

I stripped the shock and then started sourcing parts, one important piece of info here is to get hold of a manual to help with disassembly – google WP 4614, which is close enough to guide you through the process, as I damaged a seal thinking it came out in one direction when it actually came out in the other.

It was also the seal inside the piston, which is not a part you can buy from KTM on its own, you have to buy the whole piston which in the UK was £105. I did try to order one but after weeks of waiting was told it had been superceeded and the new part was £150. So gave up briefly and worked on other things.

After more research I discovered the seal was an X-ring and has a PTFE backup ring to support it.

The photo below shows most of the parts and their part numbers.

I bought the piston inner bush from K-Tech suspension and found the X-Rings at part no – QR113. The most difficult part to source was the PTFE backup ring, so in the end I found someone on eBay (Therma-tec) offering laser cut PTFE washers to custom sizes, so I had some made to my dimensions – 18.5 OD x 14.2 ID x 1.5 (all mm). All other parts came from my local KTM dealer.

If you decide to strip your shock ENSURE you depressurise it using the screw on the remote reservoir, very CAREFULLY!!

There is also a detailed rebuild here

Ok , so rebuild didn’t quite go to plan followed the manual and the shock ended up pissing out oil, WTF!

Time for some RTFM slowly, ah light bulb! I’ve knocked up a quick diagram to explain, so anyone following this doesn’t make the same mistake. Its obvious when you see it, but not when you’re just following the manual.

Other than that issue, the instructions are pretty good and I fitted a schrader valve conversion to make gas filling easier. Also bought some of the factory tools to make life easier. They weren’t that expensive and save me having to make things.

T110S is the piston rod and T144S is the breather bottle, they cost approx £50 for the pair.

Other things to note –

Compression adjuster is held on with a small allen bolt and its a pita to get out, mine was stuck on the two o-rings, also make a note of how it comes apart to ensure it goes back together the same. Otherwise the adjuster won’t work properly.

Keep the shim stacks in order, I put a cable tie through each one.

The piston isn’t symmetrical, so make a note of the orientation when disassembling.

Have lots of clean cloths and brake cleaner handy.

Just waiting on white paint for the spring.

Exhausting – Literally!

So with the end slowly appearing in sight, it was time to start fitting the exhaust and bodywork to ensure I’d run the loom in the right places.

Had to re-route the starter cable behind the relays and relocate the earth cable to the engine as it interferred with the exhaust. I was visiting Anthony at Haines Motorcycles and whilst talking about bikes a customer dropped off a R30 644 for some work, this gave me a perfect opportunity to take some photos for reference showing cable runs etc. The conclusion I came to is CCM ‘winged it’ and cables were running everywhere, on the R30 I relocated one that was being burnt through by the exhaust.

After checking the R30 over I decided that some exhaust wrap would help protect the wiring and reduce the heat that the shock was exposed to. I removed the heat shields from the exhaust, sand blasted it, painted it in flat aluminium flame proof VHT paint then added the wrap. When the exhaust wrap arrived and I couldn’t get the stainless straps sufficiently tight, so swapped them out for slim stainless jubille clips.

I then discovered that fitting the exhaust is a bloody nightmare, starting from the front, the inner exhaust stud is too close to the frame, the middle mount doesn’t come anywhere close to the frame mounting point and at the rear I didn’t need the small drop link that connects to the strap that goes around the silencer. Side note when I looked at the R30 its exhaust didn’t even have a middle mount. Looking at the middle mount I think a small rubber anti-vibration mount with fit, so will buy one to try.

The other issue that came to light was I fitted the inidcators on the rear mudguard too far forward, so they wouldn’t fit with the side panels. I’ll buy another rear mudguard and do a write-up with cutting dimensions to make life easier in the future.

Whilst at Haines Motorcycles I took one of Anthony’s Fantic eBikes, an Issimo Fun, for a quick rip up the high street. What an absolute blast, first time on an eBike, 16mph up hill with little effort. You start pedalling and think nothing is happening then the motor kicks in, I wheel span up the ramp out of the shop.

One of my friends was also collecting his new Fantic XEF250 Enduro Race, it might be a WR250F in different clothes, but it looks amazing and will be an interesting change from his Gas Gas EC250 two-stroke.