2020 CR144

you should took the thread title with a breeze of salt, but at least I tried hard to build a true CR125 with stock bore. has everything: PWK38, Rad Valve, 05-07 Airboot+sealing, cylinder base mods, head for avgas, bill's/factory pipe, pc shorty.

while it runs very clean with the airstriker and makes good power when it hits, the powerband is just too short. zero low-end, only short overrev and the 5-speed tranny. still a little faster than the 05 KX125 and you can chase 450s with it on tight tracks.

the KTM motor is much easier to ride. let alone the 20 years of technological advance and availability of engine parts. you don't need to take the whole clutch out, only to get the crank case cover of. the power valve and water pump mechanisms are much better designs. and there's the hydro clutch. I don't think I'll be riding the 125 that much again.

black bird racing. i'll throw it in the washing machine and keep it as a spare.

Catanzaro's is the newest gen frame, they look even better. but I'm still happy that i got my hands on one. there aren't much CR150s out there...

changed seatcover. had a hard time rescuing the old seat foam, but it came out pretty good. you can still see the 'impurities' from the old seatfoam through the cover if you look real close. also further cleaned the airbox and fixed the CDI mounting. loving the titanium tank:

also fixed the clutch fluid cap and the levers, instead of buying new ones. just filed the scratches and throw them into caustic soda:

stark varg tubolito tubes showed up. super easy to mount, almost slip right into the tire. still don't trust them, but let's see if they hold up. light standard tubes weight about 600g / 1,3lbs. just have to wait for the front tire and drain the rest of the fuel, than put the bike on the scale.

this is a somewhat official build. haven't done this by myself:

what I've done was a 250AF conversion. and as long as you use an 125-frame, you dont have to modify the the cradle / frame rails. the 250 engine is bigger, thus the rails stand out wider and have to be moved back to accommondate the smaller 125 motor.

all you really have to condsider is the countershaft-sprocket-to-swing-arm-ratio. the sprocket have to be in the exactly same location, as it was on the 02-07 125 engine, so most likely the mounts and head stay have to be modified.

the side alignment can be done with washers, or better proper machined sleeves.

the swing arm pivot bolt is the same on almost all Honda MX bikes. this bike here uses the Honda pivot bolt, with the '18 ktm engine.

a little working on the 2003 CR. it stood for a while with a blown crank seal and finally I was in the mood to change it. pretty straight forward work with a good impact drill (battery powered bosch with 650nm). the seal just popped out and sucked all the engine oil in

right now it's friggin cold here. that's why I moved my work shop to an insulated place, where is an oven. it's also very snowy outside, so I used the sand tires that came with the 144 and put them on the 2003 CR and added some spikes! yes, it worked really well. still tricky here and there but definitely prefer the snow over muddy weather.

mounted the front tire. again it was a breeze with the tubolito tube. then put on graphics, took it into the sun and snapped some pics. proper pictures will follow but there is still work to be done. already set up the rear shock. needed to lower sag, rebound 9 clicks out, low speed comp complete out and high speed comp halfway out. I'll send the forks out for service after christmas. don't want to risk not having them back before the holidays. the new linkage bearings are already laying around here. after they we're installed and the forks serviced, this build should be technical complete and ready for the next season.

profeshenal always chimes in on the 03

the bike hits very hard with the yamaha needle. need that for jumps right after tight corners. in that short window the power feels almost the same as the ktm motor. but the KTM pulls so much longer and has a ton of low end compared to. like i said before, easier to ride and more fun.

the 2003 will always have that kind of bog or slight hesitation when not keeping on the pipe. that's why they welded a whole new intake on the cases of the 03 factory bike. also the rad valve and richer slide+pilot help tremendously.

at the moment I only keep this bike for the looks and for snow/sand riding.

not much going on, but there were some ugly bolts that bothered me

levers also came out pretty nice

ti countersunk bolts for brake reservoir cap

changed the linkage bearings. the front bearing, where the knuckle mounts to the shock, look like this every single time:

also shaved the mounts/tabs from the rear brake adapter. always like the cleaner look. still too muddy for track riding, but couldn't help taking some pictures. still thinking about some blue coatings on the forks.

only managed to get 97mm of sag... so i purchased a softer spring and let it powdercoat in apple candy red:

fabbed up a new carbonfibre piece for the number plate, since i lost the old one on the first ride. this time I glued it on the backside of the plate. this will hold up:

shock with new spring and mud flap mounted up

still had the old oem plastics and a second set of graphics laying around. i was curious how it looks with black in the middle and a slightly enlarged blue portion. we almost came to the conclusion, that it looks better than complete red. what's your thoughts?

suspension back from service. broke it in yesterday.

jetting was clean, but the suspension was still to stiff. being 30lbs lighter than a 250F and almost 40lbs lighter than a 450, I figured out that I actually need 2 spring rates softer. with barely 90mm sag it turns amazing, but has head shake on high speed sections (but not nearly as much as the 02-07).

I really like how balanced and small this chassis feels compared to the Gen3 frame. it definitely handles better than the 02-07 chassis. it's much easier to swing the leg over, because the rear fender points down, not up. the seat and tank portion are much lower and more confidence inspiring. the engine feels like 250f with 2-stroke sound. really good stuff.

overall it feels somewhat similar to my old CR250AF with a 10-13 frame, but much lighter and flickable and with a less tremendous hit. pretty much exactly what I was searching for.

i really liked your CR build with the '24 TJ graphics and customized "CR", instead of "CRF"

i still needed softer fork springs. was going from 4.4nm to 4.2nm. this time i decided to change fork springs by myself. was easier than I expected:

air filter change is nothing special. but you may want to have look at the custom airbox. air filter is mounted upside down, like the factory 250Fs:

the ugly after market chainguide that come with bike doesn't look factory. found a used one on ebay, grinded and polished the hell out of it, inserted a new chain block and some nice ti bolts. came out pretty nice and saved about 50 grams...

last time I only changed the bearings of linkage knuckle, because I know that is almost impossible to get the old bearings out of the linkage arms. sadly the bearings of the PC linkage arms were also toast. I first put them in the freezer, then heating them up. the aluminum expands faster the steel sleeves remains of the old bearings. it worked out, but it was still a PITA

anyway, they got beaten up in the process and the ano was already scratched and started fading. so get the anodizing completely off (also the blue ano from the break tip) and polished them afterwards. another step to achieve the factory look:

also bought me wire twisting pliers. it's finally time to safety wire that sh!t

thanks man!

next on list was a 270mm rotor, which I took off from my 03 CR. I wasn't quite satisfied with the black adapter. It may looks good with black fork lugs, but I'm kind of sold for the clean polished aluminum look. While I was at it, I also de-anodized the blue brake reservoir cap. Could not find red HRC replica caps...