• 

The latest addition. I finally decided to put aside my bitterness about having to go back to basics and take another bike test and picked this up to get me to my M2 license. I put the more street appropriate tires on that came with it but other than that it was alright apart from a loud tick like an exhaust leak or something. I’ll check valve clearances and do an oil change over winter, I will have a look then.
It’s not fast but it picks up ok with a thrashing. The front brake and suspension were awful! I bled the brake several times and it got better but I think it wants a steel braided cable; the Z125 I rode on the M2 course was amazing in comparison. On the forks I put the damping clickers back to stock and then increased compression damping a good few clicks and finally found a bit of confidence in the front end. It’s felt better each time I’ve ridden it but I’m already thinking about upgrades.

Check out this sweet end of season deal!

Now with the new seat,

Notes

YZ250Fw parts list and exploded diagrams
Valve clearances:
Exhaust 0.17 – 0.22mm (0.0067 – 0.0087″)
Actuals Dec2017: L 0.203mm, R 0.178mm
Actuals Jun2018: L 0.203mm, R 0.178+mm
Actuals Dec2018: L 0.178mm, R 0.178mm
Shims: L 1.72mm, R 1.75mm
New Shims: L 1.70mm, R 1.73mm
Actuals Jan2019: L 0.203mm, R 0.178+mm

Intake 0.10 – 0.15mm (0.0039 – 0.0059″)
Actuals Dec2017: L 0.102mm, M 0.102mm, R 0.127mm
Actuals Jun2018: L 0.127mm, M 0.127mm, R 0.127mm
Actuals Dec2018: L 0.102mm, M 0.127mm, R 0.127mm
Shims: L 1.76mm, M 1.73mm, R 1.72mm
New Shims: L 1.72mm, M 1.72mm, R 1.70mm
Actuals Jan2019: L 0.152mm, M 0.127mm, R 0.152

Aug 18: Backed off pilot air screw ~1/4 turn to address hanging idle and tough warm starts (although we weren’t following the procedure in the manual)

To Do List

• Oil the chain
• Check valve clearances
• Replace upper rear shock bearing – got a set of bearings but there isn’t much play at all, probably install them next winter
• New front brake lever

Completed Tasks

June 2019

• Replace broken ASV clutch lever screw – Josh picked one up from TSR

Feb 2019

• Oil and filter change – AMSOIL synthetic

Jan 2019

• Re-fill with coolant
• Install new head gasket
• Check piston and con rod, visually inspect crank – looks good
• Check valve clearances
• Repacked muffler

Before 2019

After losing confidence in the YZ250F reliability due to the valve failure, I listed it on Kijiji for trade for a 2 stroke.  I was offered a 2004 KTM 125sx that was ‘ready to ride’ and when I checked the reviews, this was the year that they sorted out the poor rear suspension.  So I met the guy and my heart sank when I saw the condition of the bike and the huge dent in the expansion chamber but it started ok and sounded alright and for some reason, I went through with the trade.  When I ran the VIN, I found out that it is actually a 2003, great but at least the VIN was not reported stolen.

When I got it home and started looking closer I found all sorts of little issues, front fender wobbling, play in front wheel bearings and rear shock lower bearing, bent rear sub frame, fork seals leaking, it looks like this poor thing has just been neglected – I would not class this as ready to ride.  It amazes me how people will sell something without even washing it???  Pretty disappointed with the accuracy of the description but I could have walked away and the issues really are relatively minor … so far.  So I got started on fixing it up, here’s a more recent pic,

Notes

125sx parts list and exploded diagrams
Jan 2010
Race sags: Josh/Jake = 95mm, Stu = 114mm, static sag = 44mm
Jet needle set to middle notch
24 Aug 2018
Compression damping on rear shock = stock + 2 clicks
Compression damping on forks = stock – 6 clicks
Jet needle lowered to 2nd notch from top to address mid throttle sputter – we’ll see??
Original
Race sag (Stu) = 105mm, static sag = 30mm

To Do List

• Oil chain
• Repair left side air scoop mount on tank
• New front mudguard (or full set of plastics?)
• New rear sprocket bolts, with thread lock
• New front brake cable
• Ride it again, haven’t been on it this season!

Completed Tasks

Jun 2019

• Dropped the forks through the yolks so they were flush to try and address tank slappers

Previous

• Give it a good wash
• Fix wobble in front mudguard – Front brake cable clamp is missing that provided a spacer, put large washers in for now; new brake cable clamp installed
• Fix huge cracks in rear mudguard – Used the old tie wrap stitching trick
• Fix dent in exhaust
• Remove seat cover – original cover still underneath with only minor tears
• Bend radiator mount tabs back, prevent them from fouling the forks
• Threads damaged on oil level check screw – replaced with radiator mount screw since replacement screw had larger (10mm) head
• Replace worn vent screw in fork cap – not needed, with good screwdriver not much effort is required to undo
• Check rear brake cylinder, push rod comes out? – looks like it could be normal on parts diagram but the rod is well corroded
• Replace front wheel bearings
• Replace rear shock lower mount bearing – replaced with MSR bearing, not teflon
• Fix seized rebound adjust screw on rear shock – got a 2007 XC-W shock PN 12178C04 mono compression control
• Fix spring on kick-start shaft – ratchet gear was mis-aligned on shaft – rectified
• Replace fork seals – refilled with AMSOIL SAE 5 synthetic
• Thread in left side fork protector mount hole damaged – one or two threads seem ok, new screw held in with thread lock
• Install new piston – plenty of blow-by on piston skirt, got Wossner piston and ring (awesome!) and new small end bearing
• Cylinder stud broken, the nut and top of stud were glued in place!!! WTF?!?! – got the old one out with stud remover, installed new
• Screw and bucket holding the rubber chain guard on the swing arm missing – threads in hole on swing arm trashed, aluminum is thin on swing arm not much there to hold heli-coil, tried tapping to M6 and thread locking, not overly happy with it though
• Ball bearing for kick start – thanks Dan and TSR
• New right side drain plug M10x1 – threads in clutch cover are trashed!  There is a bit of the old threads left but the drain bolt slips straight in, tried installing an M10x1.5 Fix-A-Thred insert in the remaining threads but the hole was too small.  Plugged with high heat JB Weld
• Threads in oil level check screw are trashed – repaired with Fix-A-Thred repair kit
• Fix broken arm on sub frame – Josh welded it up in auto class.  Update: the weld failed so a small steel bar was fashioned and inserted.  Thought about filling around the bar with JB Weld or drilling holes and holding in place with screws but the bar was a tight fit and there should not be any load trying to pull it out the back of the bike so I think it’s good now
• Spring for rear brake lever is missing – bought new one
• Clutch basket and inner hub are both damaged – replaced with used parts found on ebay
• Clutch holding tool required – used impact driver
• Replace spark plug – ordered from Fortnine
• Install new clutch actuator gasket, screw and banjo washer – screw was too long?? had to cut one down
• Get mineral oil for clutch, top up and bleed clutch actuator – also bled the front brake again
• Little play in rear wheel – replace bearings, ordered from Fortnine with grips
• Installed new grips
• Set race sag and suspension settings to stock – race sag = 105mm, static sag = 30mm, compression damping on rear shock = stock + 1 click
• Clean rear rim
• Install new Shinko rear that came with the bike
• Adjust chain tension
• Loctite the handlebar perch mount screws
• New front tire – picked up a very lightly used Dunlop Geomax
• Split engine and remove crank (big end bearing seized)
• Install new Hot Rods crank and new bearings
• Check power valve z dimension
• Teach the lad how to short shift
• Properly repaired the rear subframe using a strip of steel drillled and tapped to take 4 M6 machine screws and replaced all the broken zip ties

November 2014 – I wasn’t really looking for another project but I had been toying with the idea of one day picking up a front engine rear wheel drive vehicle like the old Ford Escort Mk II I used to have in the UK.  I have some RSS feeds set up and one of them brought a posting for a 1980 Porsche 924 Turbo to my attention.  The good parts are that it is front engine rear wheel drive with a manual gearbox, it’s in decent shape and should have the awesome Porsche handling.  On the down side, it has been off the road for 17 years, it doesn’t run (no power to the fuel pumps), there are lots of electrical accessories not working, and it’s purple!

I apologise for these bad pictures, it is winter so I’ll have to wait for spring to update with some better ones.

• 

• 

And at long last, here are some slightly better pics,

• 

• 

To Do List

• Update the site more often!
• Fix the bloody idle hunting or low idle now!
• Find and fix oil leak from around turbo
• New tires for front Boxster rims
• New shock absorbers all round
• New control arm bushings
• Repair/replace hood latch release lever
• Check/paint rear calipers
• Remove dashboard
• Remove remaining AC stuff in PS footwell
• Check instrument wiring and grounds
• Fix instrument lights
• Hardly any air coming from defrost vents, fix/replace blower motor – no power getting to blower motor, blower motor does not spin when connected directly to battery
• Paint A arms and heat shields
• DS electric mirror not functioning and glass stained – stain covered with blind spot mirror
• Driver’s seat cover repair

Completed

October 2019

• Still struggling with this idle hunting, very strange – please let me know if you have any theories or ideas of something to try.
  Tried disassembling and cleaning the WUR, worked for a day and then hunting started again. Tried again and this time the hunting was worse and then it would cut out if you booted it in second gear, definitely doing something though. Tried one last time and blew out the little passages with the air gun … to be tested.
• Starting is still problematic and I have to disconnect the cold start valve sometimes – removed the cold start valve and blew it out while applying 12V to open it.

• 

• Got some spacers made up by Josh and finally got my longer wheel studs so I could install the Boxster rims
• Cleaned Idle Air Control Valve and fixed bad wire on connector
• Installed new LED side marker bulbs in the front
• Muffler hanger broke AGAIN! Used thicker plate to repair, hopefully the Mk3 will hold up

September 2019

• Installed brand new fuel filters, both in the engine bay and the in line filter.
• Removed and cleaned the cold start valve, it was a bit coked up.
• Adjusted the return spring on the clutch pedal.
• Cleaned the Idle Air Control valve

August 2019 - show more

June 2019 - show more

May 2019 - show more

April 2019 - show more

Previous - show more