Hello people out there - Im Paul from the UK iim 46 years old and have a TY250A, TY175, Bultaco 199A, and I have just acquired a dog of a 1971 AT-125. It starts when it wants to. I have a new battery in it and I have a spark. She runs when I leave her overnight and have a feeling its more fuel orientated....?? I'm not up to speed on the whole electrical system at all and was thinking of using a trickle charger overnight to keep the battery topped up. Also, Ive seeen the Dyno...(things) that someone is selling so could do with a bot of info on them. The AT doesnt have any lights but I have to slide what I guess was the indicator switch to the far left to start and far right to kill. I was planning of getting the whole lights etc sorted out as it looks like there are more parts available in the USA than here in the UK. Thanks guys I will be requiring help !!

Alright you primitive screwheads..listen up! (hopefully some get the movie ref!). I'm a pilot in SoCal USA and just purchased what I deem to be, after research on site, a 1971 DT1 Enduro 250cc (246 actual) with the original mandarin orange tank. The frame and engine are stamped DT1F 29958. And in pilot speak I couldn't be happier as 2995 is a pressure altimeter setting so I think it was meant to be mine lol. I purchased it last week off my local Craigslist for $80. Asking price was $75 and I had offered only $50 as it was covered in leaves and rat turds but the kid said he had another offer for $125. However, since I was the first to respond he would allow me to see it first.

Upon inspection it was / is missing the carb and exhaust so I was about to just say forget it (as he had promised it was complete) but he then said he'd take $80. (obviously sparring with a young astute professional here). Since I was there and 45 minutes from home I said ok, ..I'm in. Now please understand, the only reason why I even got into this is I have a 60 year old buddy who rebuilds 2 or 3 vintage bikes a year (all 1970-1980) and has been for the past 6 years..all with stellar results. He was down in Cabo on vacation for the week and had he been in town I'm sure he would have bought it. And I knew if worse came to worse I'm sure he would take it if I didn't want it. He has an old Yamaha 125 he restored recently which he takes camping and we recently discussed going camping together next summer up in the Sierra Nevada's. But frankly I was just really sick of seeing all of the amazing bike restorations he has done without ever getting in on the action myself! Lastly, this old DT1 was also close to what I rode in my youth sometimes (I'm 47) as my best friend and neighbor owned a mid 70's Yamaha 350 or 400 enduro.

So with all that said, I'm looking for a lot of noob advice. This thing is pretty smacked. It needs everything but all the bones are there. The frame is good, wheels are good, tank is good (meaning they can be restored) but everything need a complete stripping and rehab and we are going to do a full rebuild on the engine. I pulled off the fenders and engine a few days ago and then we tore into the engine yesterday with ease. No frozen bolts or screws and minor rust at the top of the cylinder. The crank is frozen but we got it moving some. My bud is coming back over Saturday for the rest of the engine teardown.

I mainly want to know what are all of the performance mods for this bike and how to know if someone had already "MX'd" it or not and is that even something I would be interested in or should be aware of if so. It does not have any lights on it so I was assuming maybe someone had already modded it or had at least ditched the lights at some point. Regardless, I just want a solid Enduro that is both on-road / off-road capable for occasional camping, trail riding and local grocery / beer runs. I don't want to spend tons on the bike but am willing to go up to maybe $800 in parts coupled with all my free labor. My bud is a great resource and I will handle 90% of the project as I have also done a ton of car / truck work, have a ton of tools, a full home shop, etc... I'm also already a licensed rider in my state (CA) as I own a VFR 750F that I've had for 15 years.

To the site! We have downloadable manuals fo that model, and there is a to. Of tech info in the forum posts.

Post up a pic so we can see where you’re starting!

Lots of members in SoCal, so help is not far away, and there are ever always organized group rides down there as well!

Hello lads. You've come to a great site here.
There are some great tech pages that you can access to get things moving with your bikes.
Regards Dave.

Hi Paul.
Four places to look here in the UK for parts.
Yunis parts in Darby. Ebay shop.
DKtwowheeled spares Stoke. Ebay shop
Governors bridge motorcycles,Ratcliffe Culey Warwickshire. This guy is as honest as the day is long. Ebay shop
Bhati parts ,down South somewhere,Ebay shop.

Don't deal with Freddie the frog,Ebay shop,he's very special.

New parts CMSNL. Free postage after 500 Euro E14.99 for anything else under that.
Best for nuts and bolts Motodad24 ,but he's in Texas. he does combined shipping but have a good read of his purchase info.
Elecrical rex's speedshop Youtube . Also he's a member of this site and is based here in the UK. Great bloke to deal with.

Hi all...
I'm new to the site, I joined recently after purchasing a 1972 DT250. 1972 happens to be the year that I was born also. The bike is in pretty decent original condition (same goes for me) but I'm doing a little work on it to make it somewhat more street oriented. The most significant modification so far has been the swap out of the front fork and wheel for an RD250 fork and wheel.

Hi I am Andy from Ontario Canada. Mid-life crisis hit me a couple days ago when a 1971 jt1j jumped at me on the local want ads. Santa had given me an identical bike in 1972 when I was 12 years old. I was overcome by memories of great times. Well, there is another jt1j in the garage now. It does need work such total top end overhaul( have to start looking for piston/rings after determining the size of rebore). I am really looking forward to participating in this group as my bike becomes street legal again. Admittingly, I will be seeking some help from those with experience rebuilding these little gems. Any database on Canadian mini-enduros out there? I will share my rebuild experience good and bad with the group. It is great to see a website dedicated to the Yamaha Enduro. Regards Andyminienduro

Hey Guys, new to the world of Motorcycles and Yamahas. I decided to jump in with an old classic, a 1970 Yamaha CT1. Hopefully you guys like it, I think it is a real peach and can't wait to get her running right.

I think right now my biggest issue is the O-ring on the Carb where the needle assembly joins the bottom of the bowl by the main jet.

Mr.Bky!

Looks like a good project. The o-ring referenced should still be available from the dealer or a Mikuni carb vendor and is critical to getting the bike to run right, if at all. We should have a downloadable service manual for you in the technical library link up top.

Hello Makotosun, and thank you for the warm welcome! I actually have two FSM (one is the original shop manual with the binding in the front for updates) but I can't seem to find any measurements for that Yamaha (93210-04230-00) O-ring. I have some on the way, but I'd love to pick up something locally that would work. Alternatively, who doesn't love to get a project running and save a few bucks while we are at it.

I had one quick question, which could just take a simple yes or no. Is it possible to take the main jet on that CT1 carb and just thread it in where that fitting that takes the O-ring goes? I have my suspicions it would bottom out the needle and the bike wouldn't run anyway.