1965 YJ1K

tbirdsp · Posted: Sat Dec 18, 2010 4:47 pm Post subject: 1965 YJ1K

Hi all - new here, just picked up a '65 YJ1K. I have some '70's vintage Honda 4-stroke experience, but no Yamahas and no 2-strokes.
This bike needs some love but it started up 1st kick cold in a 25 degree garage, so I figure it is worth saving. I haven't torn into it much yet, but I wll have many questions soon Wink

(P.S. - Is there no search function here?)

Rizingson · Posted: Sat Dec 18, 2010 6:47 pm Post subject:

Welcome to VJMOG. We like pics so we can see what you got. Is that YJ1K prior to autolube?

05c50 · Posted: Sat Dec 18, 2010 6:58 pm Post subject:

Welcome to VJMOG. And yes, we do like pictures....in fact, I think we require pictures! Wink

And yes, there is a SEARCH function. At the top of every thread.

...........Paul

tbirdsp · Posted: Sat Dec 18, 2010 8:16 pm Post subject:

Thanks guys. I tried to take some pics today but they are blurry. Will try to get better ones soon. Previous owner had the seat recovered.
As far as autolube - that leads to my first questions:
By VIN this is a 1965 YJ1K. It DOES have Autolube. I thought I read somewhere it wasn't introduced until '66?
Also - the bike has the leading link forks, which I thought meant it was '64?
My plan is to get it in good mechanical shape and clean it up a little, but for the most part leave the cosmetics as is, natural "patina". It looks better in this pic than it really is.

tcanough · Posted: Sat Dec 18, 2010 9:05 pm Post subject: Hello tbirdsp ;

I'm not familiar with the exact Yamaha that you are describing , but I had a 71' Gemini sst 50cc that I'm looking at the picture of and I would swear that it is the exact same engine . If that is a 50cc or so , then I think the Tiawanese must have copied the Yamaha design . Might be another source of engine parts . Good luck with your project .

tbirdsp · Posted: Sat Dec 18, 2010 9:40 pm Post subject:

The YJ1K is 55cc, YF1K is 50. As far as I can tell that's the only difference between those two. I got the owner's manual with the bike and it covers both.

rdaystrom · Posted: Sun Dec 19, 2010 2:05 am Post subject:

The Yamaha 55 is the first motorcycle I ever drove. It did not have Autolube. I believe the Riverside 60 had Autolube and looked almost just like the 55. The Riverside 60 had conventional forks and the 55 had the link type suspension.

Rizingson · Posted: Sun Dec 19, 2010 7:00 am Post subject:

The '64 YJ1 did not have autolube as you said rdaystrom, and was 55cc. I not sure but in the last year, '65 of the Riverside 55cc, it must have had injection added. In '66 Yamaha dropped the 55cc for a 60cc engine and called it a YJ2 Riverside. It does have injection as I own one, and also telescopic forks as well. All the 55cc Riversides had leading link. The 60cc Riverside was updated performance wise in mid '66 and then called the Campus 60. It took a lot of research through old magazines of that period to figure out what I had also. Just do a search here for YJ2 as there are quite a few posts on that bike as well.

tbirdsp · Posted: Sun Dec 19, 2010 11:23 am Post subject:

So do you guys agree that what I have is a '65 YJ1K with a 55cc engine? VIN is Y22-6XXXXX and it has leading link forks and autolube.

I'm wondering if the handlebars are off of another model. Switchgear and throttle seem correct but they are pretty tall and have spots for a bolt on cross bar (which is missing).

rdaystrom · Posted: Sun Dec 19, 2010 10:39 pm Post subject:

tcanough, You are right about the Gemini being very close to the Yamaha design. Around the early 70s several mini-trail type bikes came out with the Yamaha 2-stroke design but were made in other countries besides Japan. The Gemini was one as you pointed out and another was the Maverick minitrail. The Maverick was almost identical to the Gemini but I think quality was an issue with the Maverick.. The Yamaha shop I worked in during the early 70s had 50 Maverick minitrails in crates that were unfortunately lost in a fire. I always wanted a Gemini. I thought they were cool.

tcanough · Posted: Mon Dec 20, 2010 5:00 am Post subject: Thnaks' for the post

Yeah , I couldn't help notice the similarities in the engines . It would make sense for the Tiawanese to make a licenced or unlicensed copy of an already proven design rather than develope one of their own . Thanks for the information . I remember it was a strong runner and bullet proof as well .

Steve Searles · Posted: Mon Dec 20, 2010 2:33 pm Post subject: Gemini 50 Mini Trail

rdaystrom, I had a Gemini 50. Rode the wheels off it literally. Jumped it at a local track and broke the frame in half. My Mom would not let me get a motorcycle so I had this and tried to keep up with Hodaka 100's and Yamaha 125's. I was embarred but I was riding on two wheels so it was still fun. They were pretty decent little machines.

tbirdsp · Posted: Tue Dec 21, 2010 3:46 pm Post subject:

Am I correct that in order to replace to countershaft sprocket you have to remove the whole left side engine case?

What is the function of this part on the oil injection pump. Index 32 on the parts fiche, looks like a thin plastic gear, 137-13128-00-00
PLATE, STARTER YJ1K/2/2S ?

Bentwheel · Posted: Tue Dec 21, 2010 7:47 pm Post subject:

The plastic gear is a thumb wheel, used to prime the pump.

tbirdsp · Posted: Tue Dec 21, 2010 10:55 pm Post subject: