…. I’ve passed on a couple of  ‘68s in the last year as they didn’t add anything to my little collection… then I saw this in the UK and it ticked the early production box ..
Pros
early production model, by my math 911 off the line …
mostly there …single bolt rear mudguard,
 lower chain guard, blue headlamp pilot, gas tank stay, seat strap, speedo & tach..

Cons
engine seized - hopefully top end 
paid too much
no early kick start - only ever seen a photo
pre ISO so I could be in a world of trouble if I need engine parts …
Gas tank condition unknown until locked cap is removed ….
chromed exhaust…

need to make a plan ….

cheers
T1

  
 

T1 I was watching that one from DK.
I wasn't going to buy it as I've realised anything over a 175 is too loud for me to ride around here, horses go ape s#1t when they hear my RT1.
Look forward to seeing your progress with it, good luck

Not many that early left undiscovered so you're very lucky. Rear sprocket color looks like the plastic rear sprockets we used to sell back then. Is it a steel or alloy overlay type--or indeed plastic.

I like the front fender.. or lack of it and the way they protected the engine... Is that how Yamaha did that?
Sneezles61

Thanks guys … it’s gonna get a quick tidy … focus on the engine issue(s) and get it registered for the road etc

the outer rear sprocket is plastic ant bolted in place with bolts/washers … interesting mod to say the least …RT325 tell me more about them and why they were an option back in the day? Being plastic surely they wouldn’t last long?

i have a low  front fender so the high half fender will go!

cheers 

T1

Managed to get 30mins giving the bike a better look over and applying penetrating fluid to bolts etc

took the gas tank off and it’s super clean underneath/bridge so that’s encouraging…. 

the tank stay is very different from the later ‘68s … anyone know if it’s an early factory item or an aftermarket piece? I’ve not seen one before … photo of the type I have already incl for reference..

cheers
T1

  Managed to get 30mins giving the bike a better look over and applying penetrating fluid to bolts etc

took the gas tank off and it’s super clean underneath/bridge so that’s encouraging…. 

the tank stay is very different from the later ‘68s … anyone know if it’s an early factory item or an aftermarket piece? I’ve not seen one before … photo of the type I have already incl for reference..

cheers
T1

 

 Battery dated Jan ‘68 …

Very cool old battery!  I'd hang on to that. 

This forum has a lot of discussions on model changes...  and there are quite a few.  One source is the back of the "71 DT1E 250 man" in the Tech Library.  There are copies of several Yamaha service bulletins that show at least some of the changes and the serial numbers when they occurred.  The gas tank mount is one of them. 

Crankshaft end and ignition might be different, two bolt ignition cover, etc.

Nice project!  Looking forward to following the progress.

Thanks MarkT …. good shout … I have read those notes before re 6mm and 8mm stay but had never seen one.

It also looks like the early front wheel spindle is hollow not solid at the non threaded end … 

ive raided my spares to normalise the bike … front fender and kick start are wrong …. Next steps are to pull the engine and get it apart to see what I have taken on …. this is the biggest area of risk …

cheers
T1


  Thanks MarkT …. good shout … I have read those notes before re 6mm and 8mm stay but had never seen one.

It also looks like the early front wheel spindle is hollow not solid at the non threaded end … 

ive raided my spares to normalise the bike … front fender and kick start are wrong …. Next steps are to pull the engine and get it apart to see what I have taken on …. this is the biggest area of risk …



 

I've never seen a rear sprocket arrangement like the one on that bike. Is that something homemade or did they sell them like that?