The 10+ year KX500 rebuild thread

[derek badger]

Email from the French firm the CDI is coming from. Order status changed from 'awaiting parts' to 'order being prepared'.

[derek badger]

Seal head arrived, 2.5w shock oil should be here tomorrow.

I took the uni-trak rocker out to paint it and I hadn't change the needle rollers. The All Balls kit came with these parts so it seemed silly not to do it. I managed to drift the bearings out so far with a socket and the vice jaws but the vice isn't deep enough to get a larger socket over the other end to push them through. I know this as I wound it open as far as I could..so far that the split pin snapped and the vice now needs stripping down to be repaired. A die grinder and a punch are slowly getting the remains of the mangled needle rollers out but they're tough as fuck and I need to go gently.

[derek badger]

Replaced the pin in the vice and mounted it back on the bench. Got the bastard needle rollers out in the end with no damage to the main part, got to love a die grinder... marvelous tools.



Dog bone bearings and seals replaced. Wound the ride height adjuster in for my short legs.



Started sprucing up a couple of bits with rattle cans, but I've run out of time for today.

[derek badger]

I'm shopping for tyres now.

3.0 front rim, 3.5 rear. OEM fitment is 100/80-17 and 130/70-17, it's currently got Conti Twist SMs on there, which look fucking awful. I can get much more choice if go for 110/70-17 and 140/70/-17. Chain clearance shouldn't be an issue.

Any thoughts from the masses?

Current short list is Dunlop GPR-300's or Pirelli Diablo Rosso 2's (available in both OEM size and 100/140 width), or the budget Pirelli Angel City's.

[weeksy]

I'm shocked and massively Impressed.

Tbh when we met and talked on the way to Pembrey I never for a second thought you had something like this in you. You're a bit of a dark horse sir!

[derek badger]

Shock and linkage bushes all replaced and reassembled.





And as this was originally called 'Project Scumpy' by my mate Richard I thought it only fitting to wrap the remote reservoir with a cider can.

[cheb]

I've just remembered I need to do the other spacer for you.

[derek badger]

I've just remembered I need to do the other spacer for you.

I'm just working out the front axle spacers at the minute. I'll drop you a PM with the final dims for all four, but no rush as I've got plenty to do still. Cheers mate.

[cheb]

No worries.

[derek badger]

Today I removed the decals I put on years back with the exception of the the swing arm and a comedy one I quite like. I've got some period repo ones coming on the post and I found a set of rad shroud ones in the back of the shed that I might be able to do something with.









The first of the tyres turned up as did a pair of new Michelin inner tubes.



I need to come up with a solution for this monstrosity. It's the mud flap that attaches to the suspension linkage. Several of the mounts are split and it's ugly as fuck. Once again it's a discontinued part, so I either need to find something else to use or bodge it with penny washers.





Parts ready to fit and the various schematics/diagrams I've been working from. A white board and a pin board have been very useful during the build. CDI is with DHL and should be with me next week and sprocket is ordered. Don't think there is anything else major outstanding at the minute, need to get a kill switch, pushbike speedo and horn but I've got all the other wiring materials to make the small loom. Might leave the lights until after the first MOT, but if things progress smoothly I'll take a look at fitting a dipped/high, rear and brake light.



I think I've settled on the brake set up. Sliding 2-pot at the front, chose one with a flat mounting plate that I can take the pins off and attach to the bracket I fabricate. 2 pot opposing Brembo for the rear.







Front axle spacers now mocked up in plastic pipe so both wheels are central in the forks/swing arm and the dims have been given to Cheb as he's kindly offered to turn them up on his lathe. Top bloke.

[derek badger]

CDI unit arrived and is well made with the correct colour wires and terminal genders. Fitted it and it produces a decent spark, however I couldn't get it to fire more than a couple of times and then it wouldn't fire at all. Plug was wet so I suspect it was flooded, turn it over a few times by hand with the plug out and leave it until Saturday.

Same again on Saturday, and I give up as my right calf is fucking killing me. Sunday I take the carb off as I notice there is a puddle of petrol on the floor. I then take the intake boot off and the reed block. Fucking hell, I forgot how big the 6 petal Boysen reeds and the intake/transfer ports are!



Peering in with a torch I can hear the sound of premix sloshing about and have a think about how to drain the crankcases and remember I've got a Mityvac in one of the drawers. About 200ml came out! Looks like the needle valve on the carb isn't seating or the float is sticking so I've got the carb (and a spare one) in bits and will try and get it rebuilt today/tomorrow.

[derek badger]

Axle spacers arrived in the post from Cheb today and are a perfect fit. Once the front tyre arrives (stuck in Holland for some reason) and I've got them both fitted it'll be much easier to move about.

[cheb]

That's good to know, I forgot to send you the tracking number at the weekend.

[Potter]

Peering in with a torch I can hear the sound of premix sloshing about and have a think about how to drain the crankcases and remember I've got a Mityvac in one of the drawers. About 200ml came out! Looks like the needle valve on the carb isn't seating or the float is sticking so I've got the carb (and a spare one) in bits and will try and get it rebuilt today/tomorrow.

I was going to suggest a big syringe from the chemist and petrol pipe but I just googled Mityvac and it's the same thing.
Sticky floats are a pita, all the carbs on my bikes have little dinks where I've twatted them with something to free the floats off. I don't know why but MX'ers seem to be prone to it. I was once in a far away place and my missus phoned to say she was at the track, just got my lads bike out of the van and every time she kicks it over for him petrol comes out of the exhaust.

IME once you've drained it, it should fire and run even if they are sticking.

[derek badger]

Replaced the valve and tweaked the float height. Seems okay now.

[Potter]

Replaced the valve and tweaked the float height. Seems okay now.

So does it run?

[derek badger]

Replaced the valve and tweaked the float height. Seems okay now.

So does it run?

I ran out of patience and time last night when it lost spark. I'll be cleaning all earth points, trying a new HT lead and checking the stator again today.

[KungFooBob]

Always, always, always try a new plug first.

Several years racing a two stroke taught me that.

[Potter]

Always, always, always try a new plug first.

Several years racing a two stroke taught me that.

He could try reasoning with it - "Right, twat, if you don't start in the next 5 minutes you're going back under a blanket for 10yrs"

[derek badger]

Always, always, always try a new plug first.

Several years racing a two stroke taught me that.

I've got 2 new plugs. A BR8EG and a BR8EG, both have been in boxes for 10 years unused.