honda nsr50 h100 swap
Found a H100, it had a 5 speed box so i went a bit mad and rebuilt it with a fresh crank and a 115cc barrel, ought to be a fun engine.
But after i was done i needed a chassis to slap it into, queue this nsr50 that’s been hiding in a shed for far too long.
in these first three pics i have it barely hanging in with two screw drivers in both rear engine mounts with the front frame down tubes chopped off.
The top rear engine mount is the only stock one being used, i think a stock one would slide in, but this engine already had mangled case from previous owners, so i had to center it with some spacers.
And here is it on the correct level/angle, rear bottom mounts have been made, but need to be welded in, need to make cylinder mount as well.
got a full fairing for this bike, it’ll be pretty-ish when it’s done, really not sure about my exhaust options but that’s another day, first some welding.
Dax st125
No test ride we Ride.
well grabbing lunch didn’t go to plan, it appears after i had calmed down, that the new swingarm had pinched the engine breather, so after a flat out section, crankcase pressure built up and popped out the kickstart seal.
Engine survived anyway so no new zs190
Longer swingarm makes corner exit quite nice, i like. will have to up the spring preload, it’s a teensy bit softer now.
Dax st125
Getting alot of use out of my DAX clone, Skyteam st50, most mileage in the fleet! got a puncture in the front tube, and went a bit too far. First it wasn’t actually a puncture, the neck(?) pulled out of the tube, so while i waited for a fresh one to be delivered, i painted the rim! PlastiKote Exotic Sea
Couldn’t leave the rim in tatty silver, so pulled that as well, but while that was off i figured i’d finally put in that longer kepspeed swingarm, i have everything i need right?
Nah, first was the rear mudguard, swingarm is only a little bit longer but it really didn’t fit, so chopped it, fitted it higher, used all the bolts i could find on the rear, chopped up the light/number plate holder and runner mounted that temporarily as well.
Second was the chain, le sigh, i had a 428 chain for a planed upgrade, but i needed a 420 chain as i didn’t have the wider sprockets to replace the 420 sprockets.
I like the look of the modded mudguard, but the tail light has to be redone. tune back in 3~4 years when i finally fix the temporary bodge. Also a higher front mudguard to match.
Welcome back me.
Got rid of Meta, never was a big fan of Google either, now plenty active on fediverse, https://sh.itjust.works/ and https://gram.social/i/web
and now i think i’ll go back to using this blog again, lots has happened the last 5 years, so lets do a mini catch up
Computers, built this, then upgraded as well to Ryzen 7 5700X 8-Core, and a massive cooler that i didn’t realize was so tall, so the side panel needs chopping 🙁
went and did some racing, broke the crank! this bike is now gone, the nice bits ended up on the black bike and we share it.
completed the race on my dads bike.
DT175 is running again with upgrades!
removed studs, got quite a lot lopped off the top
it175 head with center plug.
new piston and a chunky spacer to lift the barrel
can’t remember any numbers, but it was a good 2.5mm lift to open the transfers, they were blocked by the piston at BDC
shot of the holes the previous owners made to lift the back, so nasty.
anyway the DT is still not right, i’m sure the ignition needs to be much more retarded.
And back to last week:
so i can’t get the six pots to work properly, not a fan of the these blue dot calipers but if i can enjoy my bike fully i’ll just have to do it.
dt175mx done blowed up
Day started well, planned to put on tyre and fit temp gauge. you can see the off road tyre was getting quite chewed.
Popped out for milk later and well i might have spanked it a bit hard, for those that don’t know 250C is melting aluminium time, if it reached 238C at the spark plug it got well hotter than that. and i wasn’t quick enough on the clutch.
I have my suspicions about that exhaust port, it’s a couple of mm lower on one side, and the high corner is the one that seized, to much exhaust T.A on a air cooled bike makes it run hot and lose power, have to find what the stock port should be!
So eh, time to make one of those spare bikes go? James helped!
More tuning to come of the DT, i had too much fun and need a two-stoke permanently in my life, it a new house rule.
DT175MX new pipe
New pipe fitted, from yambits, quite inexpensive, really gave it a proper powerband up top super entertaining to ride now. and not because the brakes are suddenly not up to the job
midrange is a little bit weak, or it was me just tip toeing about since the noise is really loud now and i don’t want to piss my neighbours off.
OF COURSE I PUT IT ON UPSIDE DOWN FIRST TIME
also note the stud on the right was buggered at some point, 10mm stud upgrade! for only one side!
 
Shots down the barrel, this is as low as i can put the piston, transfers are still shrouded, so lifting the barrel will work great.
but only after i find a better combustion chamber, blaster ysf200 head on the right is 6x97mm and the DT on the left is 6x93mm, neither head is a performance head, the offset squish was terrible idea and the tiny chamber and buried plug of the blaster won’t work too well at higher output.
it175 d/e/f will fit but are over 40 years old and a little expensive, i think the DT175 84-96 might fit, but i can’t find good pics.
DT175 tuning work
So time for some DT love
Kick start doesn’t quite fit, a s/h one is quite expensive and a new pattern one broke immediatly.
Stock filter is long gone, this works well enough, no change of rain water getting in i think.
had issues with the pilot jet acting lean, it was a little bit of rust, blew through no worries
Previous bodge job, it works so i’ll leave it.
Further work needs a stand, batterys are heavier than the bike.
Blaster 200 head, it was cheap, but the studs don’t line up 🙁 really need a better combustion chamber/centralised bowl and squish band for any performance gain.
Offset inlet, don’t like that either, can change for a rd350 one (aircooled i think) but i’m worried the PWK will then hit the case, airbox will need a lot of work to fit a filter then.
Shiny Silencer
Jetting notes
Needs a video soon.
the yearly update…
Just under a year since the last update, gotta find an easier way to post here,
anyway here’s a request, yes thats the rxs100/ysr50 back there, no it’s not coming out.
during lockdown i remember to take short spins every night for my mental health. New fav is this dt175mx, lots to do, probably never do it tho!
shed clear out
After rearrange, started work again on the rg.
Expensive, but now the shed (near 5 years since i bought it) has power, got a armoured cable, ethernet, separate breaker switch and this lovely light switch installed!
Really got to get back into this again, but projects are at an all time slow with life and other boring stuff happening.
Back to the darkside.
Some Rg125 bits first, the stock four pot is a great caliper, but pretty heavy, measure against another four pot i had lying around.
So lets upgrade to the two pot sliding caliper! ok that make little sense, but lightness comes first when you have can’t have more power.
This drain nozzle on the bottom of the airbox is the only part of the bike that hits the s1000rr shock. specifically the rubber tube thats attached to this.
Since the depth is fine i just heated it with as heat gun and slowly squished it shut.
Next i started to take a look at mounting the top fairing, stock head lamp cage hit the brake lever, looking into ways of remaking the whole lot out of aluminium.
So enough of the crap piles, my two new bikes are a freshly restored DT175MX..
..and yet another cbr6! gah actually this is only a loaner, couldn’t stand the gb400 any more so although i know i should not go back, i went back, the darkside has tight suspension and shiny bodywork.
carbs needed a little clean from sitting so long, i had the seat/side panels/tank/airbox and carbs off quicker then my dad re installing the dt175 rear wheel, he didn’t know it was a race but a win is a win.
Bling!
So very distracting.
tiny bit of noise off of the camchain tensioner, i think my old cbr6 had a different shape, may change over.
Got those blind holes tapped with the help of a snapped tap, very happy to see it on, less happy when i realised i hadn’t taken note of the timing marks..
Bench cleaned for the new head, gotta copy the porting over from the race head since that was so wildly successful.
Complete head cost €16, will those valves stand the abuse?
Cub 90 head work
Bought tools, this’ll help with foul-strokes.
speaking of the buggers, dissembled the c70 head.
Lovely isn’t it?
ports not touch much, i wonldn’t have shaped it like that
scrub scrub
polish polish, why? bored i suppose, now i have a head that could be used in a pinch.
removed the flywheel and future supercharge bracket, it’s possible my previous issues might be coil related, as the coils were off a lifan, and this engine is a zongshen.
borrowed the c70 IRK
all stop, have to gather some tools and some courage to tap these. please don’t hole the cases!
can you tell what my next bike maybe?
i consider this head a minor upgrade, the stock head and very offset plug and bowl.
tired of four stokes, so back to the rg125! deep breath, measure once and cut!
Repeat after me, angle grinder is a precision tool.
Looks good from that angle.
Fit’s here too.
bit wide here, but nothing is perfect.
Rust is lighter than carbon fiber.
