TWO-STROKE TUESDAY: 406-HOUR YZ250 BROUGHT BACK TO LIFE

“Hey MXA, after reading all your articles of Yamaha YZ250 rebuilds and why buy new etc, I was thinking it was time to rebuild my 400 plus hour YZ250 I bought new back in 2005 (got a pretty sweet 2010 YZ125 that I have had since new as well). I had a 450 four-stroke for a while, but the two-strokes are much more fun.

“I have left my 2005 YZ250 fairy stock over the years—pipe, muffler, top clamp and Ohlins shock. When I decided to overhaul it, I stripped it down and powder coated the frame, subframe and swingarm black.

“MXA often recommends running a heavier flywheel. I talked about that with our YZ250 guru and with our tracks in New Zealand being generally tighter compared to USA’s, it seemed hard to feel the benefit of it and it can take away the punch off bottom that I like.

“The thought of a KTM power valve adjuster came up with Cisco’s spring who has been doing this to some fast Ozzy two-strokes forever. But that seems to tailor more of a woods enduro sort of power.

“I have too much to list on what I did to my 2005 YZ250 and I am not finished either. I still have some tricks up my sleeve. However, as it sits right now,  it is a great setup for me. The bottom end pull is sharper but smoother all the way to the top with without an abrupt hit. The power is fairly linear but steep and keeps revving. The MXA wrecking crew should come to NZ and try it out at one of our motocross Nationals.

“I am looking to get some billet wheels sometime in next 12 months, but since the stockers are holding up I am in no rush. I also want a 2009 YZ450F swingarm and trick linkage. Since I read the MXA test of the YZ250X I am also looking into fitting the X’s 2nd and 3rd gear for the improved gear ratio.

“I could have sold my 2005 YZ250 and got a new YZ250 with a pipe, muffler and bars for what I’ve spent on this old dog, but it wouldn’t go as good, smooth and fast. The last bottom end lasted 360 hours with the clutch at 400 hours. It is all fresh now and pretty much ready for another 15 years and at 54 years old it will last till I am 70.

“Last I want to thank MXA for their many YZ250 rebuild articles to get me inspired and not build something I can’t hang onto, as you can see once you start there’s no stopping. I have been reading MXA since I was a snot nosed kid back when two-strokes ruled the roost, were cooled by the wind over the engine fins and had two shocks back when four-strokes were boat anchors.” —Cheers Graham Eyre

2005 YAMAHA YZ250 PARTS LIST:

Yamaha OEM: frame, swingarm, linkage bearings, foot pegs, pins and mounts, airbox 2015, fork guards, chain slider, chain rollers, numerous bolts/fasteners, 2016 wheels with black rims.
Pro Circuit: Works pipe, TI-2 shorty, alloy throttle tube
Cycra: Plastics, CV4 hoses (red)
Clarke: white fuel tank (took a bit of fitting, made new rubber mounts and glued bits of Pirelli  h/d tube on rub areas, on off etc)
Applied: RS factory clamps (black) 2015 on, custom bore for 2005 AOS fork  (great service)
DR. D: Radiator lowering kit
Works Connection: Front master cylinder rotator clamp, radiator braces ( moded for now higher tank mount -weld/drill  re lowering rad kit ) skid plate, elite axle blocks (black), fuel cap breather
ARC: Billet clutch perch, Memlon levers clutch, front brake
Hammerhead: Billet gear lever, forged rear brake pedal, (red tips and clevis)
Renthal: Twinwalls 999 bend, kevlar taper grips
SDG: Seat complete
TM Designworks: OEM copy black chain guide
GYTR: Clutch basket, hub, pressure plate, cover, sprockets, holeshot clip (yet to fit), air filters, 270mm front disc
P3: Carbon fibre pipe guard
VHM: Cylinder head 20.60cc chamber
Boyesen: Supercooler
Cisco’s: Powervalve spring
Moto Tassinari: V-force 3 reed block
WRP: Bolts, front caliper 270 disc adaptor (original wheel WRP 270 disc) , drive chain
Gisler moto tech: Engine port work and suspension mods (Terry hay spec  set up used back in ‘05). All engine work below the barrel and behind the clutch and suspension work Gaudenz does. I do the easy stuff.
Parts in transit: 
-Motowhips carbon ignition cover
-Hammerhead Kickstarter ( blk)
-Lectron carb 38 HV