Author Topic: dt1 question  (Read 840 times)

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Offline crossedup2

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Re: dt1 question
« Reply #15 on: December 08, 2017, 11:27:31 AM »
Hi Kenny. You should stick with the stock DT1 barrel. The Reed cylinder has a different rod length and head?? so stick with what you have.

The tank and front wheel are classic DT1 stuff and the pipe heat shield seals it for me. It is a either a 70 or 71 model. (1968/69 had a square section swing arm)

I have attached a link for a photo. (not sure if it will work as I haven't posted anything with photos for a while. ( Thanks to Vandy for the original photo)

https://imgur.com/2iAzhzS

A good seat base is the hardest thing to find and the early ones are smaller than the DT2/3 I think. If yours is in OK nick then live with it. Clean it up, fix the rust and strengthen on the foam side.

Hot up tips and there are quite a few, RT1 carby, small porting clean up, complete ignition off a DT250/400 from 1977on (Stator, fly wheel and cdi needed). YZ and IT also fit but good luck finding one and no suitable lighting coil! All bolt straight in and give you almost total reliability. (The charging circuit from the lighting coil goes straight into old harness).

Put the engine and frame numbers up. That will clear any questions.

I'm in the middle of a DT3 rebuild for vintage plate rego so happy to share information.

Good luck with it.

Peter B

 
Anything Yamaha. AT1, CT1 (X3), RT1, DT3 (x3), YZ125X,  YZ250E, YZ400D, IT175E, IT250H, IT490K . Always looking for Pre 78 Yamaha stuff....

Offline OverTheHill

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Re: dt1 question
« Reply #16 on: December 08, 2017, 12:57:56 PM »
my guess is just an ordinary DT2 cylinder as 'i think' only the head on the 250 is recessed for the pipe. Dt2MX has equal fins all around plus the pipe is sunk into the fins at the port. Found a pic on the net below if it works. I've been wrong before--just can't remember when lol. Always wife chimes in!!. ps forgot how to load pics now fotobuckets fkd. Found a link that works, man they're a nice looking bike & had one out of the crate new.

https://motocrossactionmag.com/classic-motocross-iron-1972-yamaha-dt2mx-250/

Offline sleepy

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Re: dt1 question
« Reply #17 on: December 08, 2017, 06:28:07 PM »
my guess is just an ordinary DT2 cylinder as 'i think' only the head on the 250 is recessed for the pipe. Dt2MX has equal fins all around plus the pipe is sunk into the fins at the port. Found a pic on the net below if it works. I've been wrong before--just can't remember when lol. Always wife chimes in!!. ps forgot how to load pics now fotobuckets fkd. Found a link that works, man they're a nice looking bike & had one out of the crate new.

https://motocrossactionmag.com/classic-motocross-iron-1972-yamaha-dt2mx-250/

You could be correct the barrel with the fins cut off are the DT1 GYT that is sitting here. Still something doesn't look quite right with it for a stock DT2/3 barrel and the YC isn't on my DT2 barrel.

Offline OverTheHill

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Re: dt1 question
« Reply #18 on: December 08, 2017, 10:59:47 PM »
i'd missed the pic with yc cast in somehow, i went above and below it--yeah that's interesting & wonder if it stands for 'Yamaha Competition. That's just a wild guess. Maybe it's a go fast DT2 cylinder but wasn't aware kit bits were available as the DT2MX full blown racer was just around the corner. The plot thickens. Getting confused what forum i'm on lol, i'll run it by the vintage yam one i get lost on at times.

Offline kenny

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Re: dt1 question
« Reply #19 on: December 09, 2017, 06:02:30 AM »
thanks for information guys
the vin number off the bike is dt1f 30*** its from 71 if im not mistaking
im not gonna make it original , i dont have a title on it ,  im gonna use it for occasionally riding on the track
i have another dt1 250 from 71 that is original for riding on the street
im gonna use the original cylinder the other im gonna keep as a spare
the seat pan is ok , but i was thinking off putting another seat on the bike maybe one off a mx 250 from 73 im not quiet sure about that yet
i already found another fuel tank for the bike , i bought a aftermarket exhaust ( not gyt really like one off those )  parts off these bikes are hard to find in my country i got lucky when i found these bikes in germany
for now im gonna use the original ignition , maybe in the future ill change it , from it s i have a few spare complete ignitions for back up for my it s

here are some pics off my other dt1 it original comes from wisconsin







cheers
kenny


Offline Iain Cameron

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Re: dt1 question
« Reply #20 on: December 09, 2017, 11:15:57 AM »
Kenny there is a page on Face book that is devoted to the DT1 , lots of parts . With the ignition any of the DT400 CDI systems will bolt straight in no problems . The GYT pipes are around but the price shows how rare they are . With the GYT pipes you also need to change the jets in the carbie , lower the compression or use a GYT head , the ignition needs to be reset to these changes as well . Iain
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline Berwick Boy

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Re: dt1 question
« Reply #21 on: December 09, 2017, 01:39:15 PM »
Love your Wisconsin 250, Kenny.  Gorgeous!!
Man ... they were such trick designs.
Imagine parking it outside a cafe !!!!!
(PS: Click on Kenny's icons to expand into full pages)

Offline kenny

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Re: dt1 question
« Reply #22 on: December 10, 2017, 07:48:33 AM »
thanks im glad i found the bike
ill check the facebook group out
the gyt heads they are not easy too find aswell i assume ?

cheers
kenny

Offline Iain Cameron

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Re: dt1 question
« Reply #23 on: December 10, 2017, 11:40:25 PM »
The GYT heads pop up on US evilbay quite often , But any high comp head will do . Webco , ACE , and GEM made heads for the DT1 . even a DT2MX head will bolt up .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline farmpro

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Re: dt1 question
« Reply #24 on: December 11, 2017, 02:10:10 AM »
Or use a 74/75 YZ head.They would just have extra holes as would the DT2MX.

Bill Davis       Texas Vintage Racing Club.

Offline Iain Cameron

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Re: dt1 question
« Reply #25 on: December 11, 2017, 10:32:39 PM »
Long time no hear Bill .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline farmpro

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Re: dt1 question
« Reply #26 on: December 12, 2017, 02:36:17 PM »
Still around Mates.Hoping to come over again next year with my wife.She's never been.Any Racing over there in January or February ???

Offline Iain Cameron

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Re: dt1 question
« Reply #27 on: December 12, 2017, 05:09:44 PM »
Its the hot months here in Jan and Feb I don't think we have any down in my state but up on the mainland there might be some . Send me a PM when your close to coming over as I will be on the mainland in Queensland in early Jan . Iain
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline sleepy

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Re: dt1 question
« Reply #28 on: December 12, 2017, 06:03:29 PM »
Since we are talking about DT Yamaha's thought I should put a couple of photos of the DT/RT clutch worms as I still have a few from the last batch I made. Cost $50 plus post. Simple to fit and gets the clutch actuator back to good health. Made from bronze and with a bit of grease every now and then will last well and give a more positive clutch action than the original.




PM me if anyone wants one.

Offline shelpi

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Re: dt1 question
« Reply #29 on: Yesterday at 02:14:03 PM »
hi
i had a question about the dt1 250 from 71
i bought an dt1 from the usa but the headlight is a sealed beam one and it is broken i know back in the day you just throw it away and got youself a new one , does anyone have an idea what kind off headlight i can use to replace mine
also i bought a dt1 barrel with on the side YC 246 cc i ve been told its a barrel of a dt1mx from 71 or 72 does annyone know if this is correct ?

thanks

kenny
just saying I have a CT1 reed valve jug with yc on it