I have been working with the Yamaha 2 stroke bikes for more than 32 years. The first motorcycle I ever owned and worked on was a 1965 Yamaha YDS3-C (Big Bear Scrambler) that was given to me in 1979 (yes, I know, I'm dating myself here).
My first motorcycle - 1965 Yamaha YDS3-C, Big Bear Scrambler
I was constantly tinkering with it, either fixing something I thought was wrong or improving something I knew was wrong. Many times I would go down to the local Yamaha dealer and talk to the salesman who I though was just an ex-mechanic but later found out he was the owner of that Yamaha Dealership. We would converse about the issues I had and ideas I had about improving some of the general issues with that model. I must have had that engine apart at least a half dozen times. The sad thing is, I never really appreciated that model as much back then as I do now. That bike got me started on a whole new Yamaha 2 stroke adventure. I knew nothing about 2 strokes or even motorcycles back then. Sure, for years I had been fixing lawn mowers, go-carts (made my own, see pictures below), mini bikes and even did some minor engine repairs on an old Rambler and Volkswagen cars, all before I was 13 yrs old. They were all 4 stroke engines, I thought "how could a 2 stroke engine be any different", I was wrong and I learned a lot from that YDS3-C.
My very first motorized go-cart that I made from my previous down hill coaster go-cart. Engine is from and old lawn mower. I was 11 yrs old
My second go-cart that I designed and built all myself when I was 12 yrs old. Check out the lawn mower tires on the front
Yes that was a very large engine, a Briggs & Stratton 7hp from a rotor tiller I bought from a neighbor
I had the YDS3-C for about 3 years (I do wish I still had), sold it in 1982 after buying two basket case 1975 Yamaha RD350's. Yes, they were literally in baskets and boxes when I brought them home. I spend about 2 weeks assembling the best parts of the two basket case bikes into one runner. Less than a month later, I disassembled everything and started my first restoration project. It took about 3 weeks to complete (I didn't have a job back then) and the RD turned out really nice.
The first of my many restoration projects - 1975 Yamaha RD350, and yes, I did all the paint work myself - I was 18 yrs old
About 2 months after completing the restoration on my RD350, I had my first street race against a Honda CB900. The race was going good for me, I was beating that Honda................ until...............let just say, "marbles in a tin can", not a good sound at any time, let alone during a race, for which I ended up losing because of engine failure. I had to push my RD almost 3 miles and half that was up some fairly steep hills. Once I got it home, I dismantled the top end and found I had burnt a hole in my piston big enough for the spark plug to drop through. Guess where I went next, the local Yamaha dealer to buy parts and discuss my woes. It seems that during all this 2 stroke learning stuff I neglected to learn two of the most important items, carb jetting & plug reading.
So, after a very lengthy topic about jetting, it was time to put my new found knowledge to work. I spent the next several weeks or so disassembling and reassembly the top end of my RD350. I would change the port timing, add different carbs, add different pipes, all while jetting and re-jetting it over and over. Of coarse there were my weekly talks with my mentor at my favorite dealership. I got pretty good at this jetting and at reading the plugs. I thought I had a fairly good grasp on this 2 stroke stuff but didn't realize just how good until one day I went to the local Yamaha dealership to buy some parts and got offered a job there........as a mechanic. I thought wow, I'm 19 yrs old, how cool is this!
At that moment is when I found out that this salesman, the ex-mechanic that I had been having all these deep long 2 stroke theories, tuning and design discussions with was in fact the owner. He didn't want my answer then, he said, "Come back the tomorrow and we will talk". Well, I went back the next day and started work there a few days later. I worked there for a few years until someone else bought the place and I really didn't like them so I left. I did learn a lot about many other bikes during my stint at Yamaha but still prefer the 2 strokes.
Through out the years I have personally owned 3 - R5's, 8 - RD350's, 14 - RD400's, 4 - RZ350's, 1 - YDS3C, 1 - YDS5, 1 - DS6, 1 - DS7, 2 - RD250's, 1- R3, 1 - RD125, and many other Yamaha models that at this moment I don't remember what models they were. I had many other makes and models as well, but most were Yamaha's. Unfortunately I didn't take pictures of all of my bikes, I wish I had. I have still been working on these types of bikes on and off, so, rest assured I do know these models very well.
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