Who wants to know about old Yams ?

[JimR]

Hi,
if you have some technical issues with Yamaha's from the 1960's~1980's post a reply here I may be able to help
Regards Jim

[rpv]

Jim,
I have a few older Yamahas, and hope to add at least one more. I have been actively collecting manuals and the odd part over the years, but would like to begin getting more serious about restoring old Yamahas. I currently ride a nice '78 XS650, have a nice little LT2 complete and all original, and am in the process of restoring an RD250 and a YL1.
I am looking for an old Yamaha, and perhaps you can help me. The first bike I ever rode on belonged to my uncle, and I want very much to find one like it. Problem is, he doesn't remember much about it, and there are likely no photos. It would have been used in about 1970, was a 250 with low pipes, and was a light brown color. A YDS3 perhaps, but I have not been able to find a picture of one in that brown.
Anyway, I am very much interested in the older Yamahas, and am pleased to make your aquaintence.

[YamiChick]

Maybe an YR5? It was produced on 1970 and it's brown color

The YR5—known simply as the R5 in the States—was a real star in its day, though. Yamaha came late to four-stroke super-bikes, releasing its debut model, the XS750, only in 1977. But the firm's dynasty of two-stroke middleweights provided some of the great bikes of the Seventies and Eighties, with a near-unbeatable blend of performance and value. And while the RD400 and the later, liquid-cooled LCs are more familiar to most riders, the models that started the legend were the air-cooled RD350 and the YR5, its look-alike predecessor.

In 1970, the year the this model was launched, Rod Gould won Yamaha's fourth 250cc world championship, following fellow Brit Phil Read's three titles in the Sixties. Its design could be traced back to the YR1 of 1967, and was shaped both by racetrack development and by Yamaha's smaller roadsters. The YR5 was the biggest of a visually near-identical family of 250, 200, and 125cc twins. Like the smaller models, the YR5 used a piston-ported, 180-degree crankshaft motor, in this case with dimensions of 64 x 54 mm for a capacity of 347cc.

Yamaha claimed that the YR5's steel, twin-downtube frame was designed using knowledge gained through racing, where privateer Yams were already becoming popular. Suspension was the typical combination of narrow forks and preload-adjustable rear shocks, holding 18-inch diameter wire-spoked wheels. Brakes were drums at both ends, with a twin-leading-shoe unit up front.

Skinny and simply built, the YR5 weighed just 150 kg (330 lb) with half a tank of fuel, and at a standstill it felt light and maneu-verable. Its mixture of burbling, rattling tickover noise and the unmistakable smell of two-stroke oil brought back memories of other Yamahas. For what was in its day a hard-and-fast sportster, the handlebars seemed ridiculously high. Forward-set footrests and the thick dual-seat added to the almost relaxed feel.

So did the YR5's straight-line performance, for the little twin didn't come close to providing the high-revving thrills that I had expected. Why I had, I'm not quite sure. Some modern 125cc sportbikes make almost as much power, after all. Flat-out on an open road, the less-than-aerodynamic YR5 ran out of steam before 100 mph (160 km/h) however hard I tried to hide behind the clocks.

At least the Yam had a broad spread of power, pulling cleanly and fairly smoothly from below 3000 RPM to the red-line. That enabled it to cruise at an indicated 90 mph (145 km/h), though hills would knock that figure down to 85 mph. High speeds soon became tiring, of course, thanks to wind blast from the upright riding position. Comfort was much better at slower speeds, though the YR5 didn't like being treated too gently. American riders who stuck to the freeway speed limit found spark plugs prone to fouling.

Contemporary tests described the YR5 as a quick-handling machine, with its weight down low, good suspension, and excellent traction from its tires. This YR5's handling was certainly fairly quick. Despite the bike's 18-inch front wheel and old-fashioned steering geometry, the combination of light weight, wide handlebars, and narrow front tire meant it could be flicked into bends rapidly and effortlessly.

Underdamped suspension at both ends ensured that it wasn't a good idea to get too aggressive, though. The soft forks and the Yam's rear-end weight bias made the YR5 feel very twitchy at the front, while even fairly modest cornering speeds had the rear end wallowing, too. Doubtless this bike's shocks had deteriorated with age, but even so it was obvious why so many riders fitted after-market units.

This bike's front drum brake had plenty of power but was rather fierce, especially considering the narrow, ribbed front tire through which its power was being transmitted. Despite the tires, it wasn't hard to get the footpegs touching down.

In case all that sounds too critical, I should add that riding the YR5 was still great fun, at least on a-twisty road, provided allowances were made for its age. And that's how it should be— because make no mistake, this was the poor boy's superbike of its time. Back in 1971, when this particular machine was built, it would have taken a well-ridden example of Honda's CB750 to stay ahead of the screaming stroker on anything but a long straight road.

The same could be said of this bike's two-stroke successors such as the RD350, RD400, and RD350LC, as they continued to give larger bikes a difficult time for many more years. They were fast, furious, light, agile, good-looking,"and unbeatable value for money. Just like the original YR5 itself.

From Cycle World, jun. 1970

"Winding roads, downtown traffic or 70 mph freeway grind, nothing seemed to make much difference to this stout two-stroke. Power is on tap from well down in the rev range to around 8000 RPM, where it begins to taper off. Mid range torque is noticeably better than with previous models, as the R5 pulls like a 500 when you twist the grip in fifth.

The R5 may be described as a quick handling machine. As it has most of its weight down low, there is little top hamper to inhibit the rider from pitching the machine aggressively through his favorite set of bends... We would like to see the wheelbase extended slightly to slow down the quick handling and put more weight on the front wheel.

The R5 offers substance, as well as appearance. Within limits, it will do things most of the more expensive superbikes will do, at lesser cost but equal fun value."

Source Superbike of the seventies

[JimR]

Originally Posted by rpv

Jim,
I have a few older Yamahas, and hope to add at least one more. I have been actively collecting manuals and the odd part over the years, but would like to begin getting more serious about restoring old Yamahas. I currently ride a nice '78 XS650, have a nice little LT2 complete and all original, and am in the process of restoring an RD250 and a YL1.
I am looking for an old Yamaha, and perhaps you can help me. The first bike I ever rode on belonged to my uncle, and I want very much to find one like it. Problem is, he doesn't remember much about it, and there are likely no photos. It would have been used in about 1970, was a 250 with low pipes, and was a light brown color. A YDS3 perhaps, but I have not been able to find a picture of one in that brown.
Anyway, I am very much interested in the older Yamahas, and am pleased to make your aquaintence.

Hi There does this look like it ?

If so it will be a YDS7 .... the DS3 was mid sixties rather than early 70's. The colour if the same as the picture was called Mandarin Orange but it did look like light brown. Please remember as I am UK based , colours may be different across in the states. The DS7 was the 'test bed' for the RD version and was quite a good bike in its day excluding the rather poor main bearings fitted to the crankshaft !!
As a foot note I have ridden & repaired every bike in your stable, I may be a little 'rusty' with some of the settings for them but if I put my mind to it I could get them back into mind (it was many years ago) !!!! The one I am having problems with the most is the Twin Jet (YL1) and for sure I wish I still had one of those !
Regards Jim

[YamiChick]

Aw.. Sorry I was off,,, but glad we have a vintage Yamaha expert JimR

[JimR]

Originally Posted by YamiChick

Aw.. Sorry I was off,,, but glad we have a vintage Yamaha expert JimR

Hi
no you were not off DS7 & R5 looked the same .. in the UK they were different colours but in the States may have been the same but I doubt it , When I sort out some way of adding photo's easy to the site I'll add all the memories of Yamaha's 25th birthday party.. It was one hell of a party !
Regards Jim

[walklatch]

Hello Jim,

can u help? 1984 rd350ypvs, 31k on engine think it rd350n model. Anywat i have restored but never could remember how to connect tacho, no obviously wiring, do you happen to know where the pulse for rev's connect to the counter?

Great if u could help

Walklatch

[JimR]

Originally Posted by walklatch

Hello Jim,

can u help? 1984 rd350ypvs, 31k on engine think it rd350n model. Anywat i have restored but never could remember how to connect tacho, no obviously wiring, do you happen to know where the pulse for rev's connect to the counter?

Great if u could help

Walklatch

Welcome to the Forum
I seem to remember the 31K YPVS had a cable driven tacho, the cable connected to it's drive on the engine just forward of the rear engine mount.
The later models the tacho wiring ran into the loom and picked up its pulse from the cdi unit