'77 Yamaha IT250... supermoto-tracker-thing. lots of pics.

today with 65f air temp, near sea level, 30in baro... finally got a good baseline jetting. FINALLY.

'77 YZ 250 jug/piston
modified IT 250 pipe

VM38
#30 pilot, air screw 1.5 turns out
#330 main
2.0 slide
can't remember what needle is in it at the moment.

motul 710 @ 40:1 with a good amount of residual oil after a typical jaunt.
87 octane (no signs of detonation... yet... but it's also cool out)

starts cold or hot in 1 kick. rips along nicely from off idle to WOT. stoked. almost shit myself when it came on the pipe so early... it's been running smooth, but never what i thought it should be up high, until today.

Very cool project.Always like to see someone turn junk into something nice and useful.I did the extra reed ports,mild porting, a bigger carb,Boyeson reeds and a chunky K&N on my '74 DT360.Yours is looking great.

thanks!
i'm still not sure mine's nice or useful... kinda fun, though. kept my hands busy in between other projects, and i have times where i need that busy.

right now that busy thing is finish carpentry on our 100 year old craftsman style house. i'm aching to get back in the garage, though... want to finish this bike, i've a 60s mini bike to finish for my daughter, gonna need another project bike after that...

first commute day on the IT.

the headlight fell off, tail light stopped working, sputters mid throttle under load, realized there's no rear-view mirror, wheelies when it gets on the pipe... all around, a good shake down run!




edit: and then there was this. started running rough. felt lean. then rich. then lean. lowered the needle clip to be on the safe side. kept loosing power. then noticed the oil all over my leg. right. that's not normal. left side of the motor was covered... oil coming from the head gasket. got me home, though.

on the plus side, it took literally 10 minutes to strip the bike down to this point. i love old 2 strokes. pull seat, tank, pipe, 6 nuts and the head is off. i probably could have left the seat and tank on. my almost 4 year old son helped.

Should have a reed block on the air intake after the carb.

aaaaand it does. even has fancy ass new reeds on it.

yup- i knew what it was the second i saw the oil and had the high/hanging idle.
i *hoped* it was just the base gasket, but *knew* it was the boyesen port on the left side.
when i ported it, i knew it was really close to the exterior of the jug. after some heat/cool cycles it cracked and formed a leak.

to fix, i drilled it out from the outside, tapped it... used a set screw, coated the threads with the all mighty JB weld. once it cures i'll drill the port on that side again (which will go partially through the set screw). for what it's worth, JB has a working temp of 500f... i've used it to raise/shape intake ports on motors that run a lot hotter than this, with success. figure it'll do the job. where's my beer?

the stock headlight, even with an H1 bulb, sucked... so this.

30 minutes to fab a headlight bracket (mild steel)
grabbed a BLC accessory light out of my stash
put a cheap ECE wide flood lamp with an H1 bulb
should be MOAR light now.






the tabs on the side are for a lamp guard that i'll make eventually...

next... i want to raise the forks again, longer YZ rear shock... and i just know i'll stumble across large case YZ400 motor one of these days... or hell, a 490. i'm a fabricator. anything fits anything

since i've been using it for commuting and riding all over town, figured some mirrors were needed... $4 later, i've got 'em!



just some cheap ass blind spot mirrors from the parts house, drilled some holes in the back, busted out the zip ties... a bit of innertube to keep 'em from sliding around... done. sorta ghetto, but they actually work pretty well.

The IT in the thread title caught my eye. I love ITs! One of these blue moons I'll find a decent one for a build.

You have got some great shade tree skills! From porting to seats...thats really great. I have to ask (because I've had it on my todo list forever) do you use one of those heavy duty sewing machines or just a regular old singer type? I always wonder if the home ones have the horsepower to do seat material.

I've been using it to commute, ~11 miles/day, in the city. Small, light and torquey enough to have a blast on (keeping in mind i'm used to old bikes, it probably doesn't compare well to anything "modern"). I've put a couple hundred street miles on it... and only about 4 off road miles on it. gotta work on that.

the seat material is marine vinyl, about as thick as the stock seat cover. any decent standard "home" sewing machine will do great. what doesn't do great is me... i can fabricate, paint, build, etc... but sewing is DIFFICULT!

ok... two months of commuting, running errands, beating it up, dropping it, etc... going strong.

the re-wound stator is holding up, but i've dropped to a 35/45w H4 bulb. anything higher and the light is dim at/near idle. the 35w low beam is plenty bright.

the front tire (19" mefo trials) absolutely sucks on wet asphalt and even worse on concrete sections of freeway. on the wet it has tons of traction until it suddenly has none. no feedback. on the freeway it TRACKS bad. come to think of it the tire is equally bad on the grass, gravel and loose dirt. the only place i really like it is dry asphalt.
the rear tire (18" pirelli mt40 trials) is great, save for squirming when leaned. great traction everywhere.

Maybe try a Shinko 19" DOT trials tire on the front?

I really like this bike.........the way it was before it was molested.
It would have made a great dual porpose machine just by changing tyres, go to trials universals or even straight road tyres. You can get ribbed 21's for fronts and some pretty good rubber in 18's.
The standard porting on an IT is MADE for commuting with low down torque and very good mid range.
Why do you want to make it higher with longer shock and higher front? Not handle bad enough now? Not getting enough height with your highsides?
The time is getting close where you will not be able to buy an original old bike that hasn't been molested.
Some must do tips: exhaust wrapping, clipons (Have to be too low to be practicle), manditory photos in front of graffiti, retro gear for riding eg, 50's leather jacket, cordroys, half face helmet (Painted matt black) and swede shoes with rivits.
Oh and you need to put "Saved" and "Barn find" in there as well.

you're missing the point that this was a dirt cheap bike that was in piss poor condition, had some parts pulled out of a pile and all thrown together for very little coin.

before it was molested, it was molested and abused. the stock plastics were broken, painted with layers of spray paint. stock tank full of cracks and leaks with a stripped out tap and a stripped out cap. not savable. forks were rusted badly enough that seals would last maybe two strokes, the rim was full of cracks and the spokes rusted solid. not savable.

it has a trials tire on the back, on the stock 18" rim. it's got a trials tire on a 19" on the front because that's what i had laying around.

why higher? shit ground clearance. lower than a YZ of the same era. i'd also love to have an extra inch and a half of travel in the rear.

re: porting. what's your point? the entire powerband was moved up by maybe 300rpm and it's got gobs of low end. now, if we were talking about an early 80s IT... mucho better low end, stock. not the '77.

Mebe I am

You do much offroad these days? Jump a lot of logs? Find a 21 that might lift it up a bit.

I do like the back end treatment you have now with the old seat/guard and light, looks a lot better than that "Racing" glass one. Must have had good milage with it it was going down a steep hill all the time.

Guess I just commented on this one because of the rash of "Saving" threads from "Barn finds". I like a more classic style. Bottom line is your bike do with it what you want.
Always a good quote
The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed.”
― Robert M. Pirsig, Zen And The Art Of Motorcycle Maintenance: An Inquiry Into Values

i've got a 21 for it now. doesn't lift it up at all. overall this bike is small and low; half the time i feel like i'm riding an 80cc. it's not nearly as tall (seat height or ground clearance) as a '80 IT 250.

at one point i was building this just for flat track. not clear at all what you're referring to about a steep hill. i think that's a discussion that should be had over drinks

we might agree more than you think on this. near every "cafe" bike i see, seems to be an unridable atrocity... usually ridden by some hipster dude (chick?) with skinny jeans, $70 t-shirt and fancy riding loafers.

that and the slew of "choppers" that got built out of hacked up 80s japanese bikes with questionable build quality and even more questionable sense of aesthetics. and this coming from a dude who's really, really into choppers (although generally just 50s - 70s harleys)

generally, though, i like a restored bike 99% of the time over something that was "customized." maybe some era appropriate performance parts... and modern rubber...

it is.

Nice bike man, reading thru your build gives me some good inspiration for my DT400. Looks like a sweet little ride for cruising around town on and I wish I had the skills and equipment to do the machining work you do. I do appreciate a ground-up restoration but theres something about putting your own touches into an old bike that really speaks to me. Nice work

I know this is last year, but I just got inspired to do something with my old 1977 IT400 sitting in the shed and went searching. Got more than I expected with this thread. Love the build, and you're in P-town!

I need it for 2 things:
1. Alley Sweeper 2015
2. Salem Indoor FT

Thanks for the inspiration. I'd love to buy you some beer and ask a few questions.

-Kevin

still have the thing... haven't been riding it much lately; swamped between work, home and family.

dug out the old tank, decided to finish polishing it...
maybe get some new side panels from DC plastics...
then re-do the seat to fit this tank more betterer (tank is sitting about an inch too far forward in the pic)...
if i'm going that far, may as well put the airbox i found for it on, too...
before you know it, it'll be stock/restored :)