YZ125K Rebuild

[Billet YZ]

YZ 125 K & YZ 125 L  share the same part number for the exhaust.

[alexbrown64]

Its a big bug Ekka... just gotta get out and ride more but it is so hard these days... barely a riding spot open in WA anymore.
Billet, the part numbers for K and L are:

EXHAUST PIPE ASSEMBLY
39W-14610-00-00
$296.99
PART OBSOLETE

EXHAUST PIPE ASSEMBLY LASSEMBLY
24X-14610-00-00
$309.99
PART OBSOLETE

They are interchangeable and look very similar, but the L is slightly narrower.  The K muffler is non repackable and the L muffler has rivets and is repackable.  I have the L muffler and will keep that as i can repack it as neccessary.

[alexbrown64]

The bike is almost there... i fitted the DLS to the race bike and it works well (in the shed).  These brake plates are hard to get and expensive.  It came on the old OZ model K i just bought.  I whipped it off, cleaned it up, adjusted it and fitted it without too much trouble.  I grabbed some adjustment instructions from various forums and have added them to my website.  The DLS for the 38mm forks is different than for most other models.  The lug that slips into the fork leg is only at 1 o'clock on the 38mm model as opposed to 3 o'clock on larger forks.


Cheers,
Alex

[tony27]

Same plate as fitted to the G & H model 465s & H model 250s, have a later model plate sitting in the garage that I robbed parts off for my 465

[alexbrown64]

Yes, i just read the YZ125L magazine report and the 43mm forks on that had the 1 o'clock insert.  Most plates i see for sale though have the 3 o'clock insert and they are all heading up over $2-300 US now.  Some DLS plates only have the steel arms too...

[micko]

Alex, you should come riding with us on Saturday @ducksnuts mx park. (check it out on the web) Would be great track for your bike.
Micko

[alexbrown64]

I would love to go for a ride and meet some of you Saturday Micko, ... but i am still away on the Wheatstone platform.  I looked up the ducks nuts park and it looks brilliant.  Thats the sort of thing i'm looking for.  Will definitely get there soon i hope.  And your right, the 125 would scream on those tracks.  If you get there, please post up some pics of the day.
Cheers,
Alex

[SimonC]

If you are north of the river I can recommend the Pinjar Off Road Area - remarkably good little facility if you go midweek, a few different trails to ride on, and it's free and you don't have to pay anything to Motorcycling Australia for the privilege of riding your own bike. Don't go near it at a weekend though.

[micko]

No worries Alex, will get some pics and go pro footage. Cheers Micko

[alexbrown64]

SimonC, i might take a run up to Pinjar to test the bike out at some stage.  Someone was saying they have closed a lot of it due to development.
Should start a thread up with pics on riding areas around the Perth area.
Cheers,
Alex

[SimonC]

Whole thing is currently closed due to forestry operations, I think back to normal in July. Good place to test your suspension out.

[alexbrown64]

I rebuilt the OZ version wheels and installed them on the bike.  This took some time and effort, so i made a tutorial up on how to relace conical hubs, and posted it up in the tech section.
I have used the original rims but powdercoated them black.  It was going to cost $200 to re-anodize, or $400 for new rims. The powdercoaters blasted and painted them for $10 each.  I also had the hubs done for the same price and got the frame done at the same time.
The zinc on the original spokes was worn out so i have put those away for later electroplating.  I also broke one removing it, but one of the guys on here is hopefully sending me one to replace it.  I located a front and rear OEM set from Tamor Trading.  Tony did me a good deal and he express posted them to me.  I got everything back and relaced them.  I cleaned, inspected and repacked the bearings then polished up all the bolts, adjusters and axle.  There is also another 50T alloy sprocket on there so that i can easily swap wheels over with the other 125K.
Cheers,

[Tomas]

Like your enthusiasm Alex. Thought I have too many spares having a spare set of engine cases and set of gears for my RM. Good work 

[Lozza]

Woodruff key isn't essential flywheel will stay put without it. Few more pics of the gear lever please 

[alexbrown64]

The gearshift was sent to the scrap yard to be sent to China to be made into Chinese pit bikes.  I thought about whacking the rotor in without the key, just like my PVL, but i found one, so in it went.  I think i have to many spares now Tomas.  May be giving some of the L cases away if any one wants some.. just pay for postage.
Well, feeling good as West Coast kicked butt last night, i headed to the shed this morning before the kids woke up and had a bit of a go at the bike.  I got all my seals fitted to the clutch cover.  The water pump seal, i pressed in with a G clamp.  I have a new power valve linkage, but i only use it to compare wear against my old ones.  The used one in this case was OK, so i re-fitted it.  This cover was now ready to fit.

It was now time to fit the engine.  All went well and it slipped straight in.  This is when you adjust the clutch.  Loosen the nut in the centre of the clutch hub and wind out the rod slightly.  Then adjust your cable so that the clutch arm that comes out of the case on the right side aligns with the small mark on the case.  Then wind the clutch rod back in until it touches and do the lock nut back up.  We are now ready to fit the clutch cover.

To fit the cover, as explained earlier when i refitted the Lechien one, you have to fit the governor in the clutch cover first.  I picked up my governor and realized the spring was floppy.  My spare governor (from an L) had a helical gear but had a tight spring.  Using pics and diagrams, i rebuilt one good governor and the spring felt perfect.  The previous owner must of had it apart and left a few spacers out.

Fit the governor in the clutch cover with the power valve plate going into the groove in the governor.  Have your dowels and gasket on, the gently work the cover onto the engine.  Align the water pump shaft which is on the cover to the white gear on the engine by turning the pump.  Then align the governor into its final position by turning the engine over slowly with the kick start.  The case should just slip on that final 20mm.  I decided to bling the bike by polishing the water pump cover and fitting it together with a red GPI silicon hose.



Thats it for now... its time to assembly the ping pong table which looks like it will take more time and has more parts than this bike...

Cheers,
Alex