Yamaha YSR "The Pole Smoker"

[Duke Blackwood]

Does everybody know who Kenny Roberts is?

Kenny Roberts Sr. won three 500-cc Grand Prix world championships, but he also merits an odd footnote in the motorcycle hobby--the Yamaha YSR 50.

Roberts won his three titles from 1978 through 1980 while Yamaha was selling the last two-stroke motorcycle in the U.S. before emissions rules tightened--the RZ 350. There was even a yellow and black Kenny Roberts signature edition, capitalizing on his 500-cc Grand Prix championship machine.

The story goes that as a joke Roberts' crew modified a little "monkey bike"--so named because it resembled a circus stunt bike--with 12-inch wheels into the RZ 50, a miniature version of his faired racebike that he could ride in the pits. The quirky little machine attracted so much attention that Yamaha sold the model publicly from 1987-92. The small bikes had the same controls as full-size bikes and could be ridden like the larger ones.

The factory YSR wasn't made for racing, there's only one fork spring, only one triple clamp on the forks--the top one just holds the handlebars. The whole bike only weighs 75kg (Less than this rider).

Everyone heard of the Suzuki TS185? 

 

This 18hp beast was the fastest thing to hit the farm since the horses got into the cocaine patch.

 

 

[Duke Blackwood]

A couple of years back I bought a YSR50 with a TS185 engine transplant, half complete, from an estate garage sale; it may be the best value purchase of my life. I haven't touched it, never got it running.

 

 

After reading about the upcoming Urewera Undertaking, I knew it was time. The factory YSR frame is only rated for 65kgs and I weigh more than that... I'm also looking at a horsepower increase of something like 240%... and I should probably make some kind of concession for the gravel. So there's a bit to be done. Step one, amalgamate the looms and achieve stable idle voltage.  Step B, celebratory burnout. Watch this space.

 

 

 

[Duke Blackwood]

Alarmingly the bike is already showing evidence that it intends to reject its new engine; by breaking in half and letting it fall out

[Duke Blackwood]

To avoid this, I've made up some frame gussets and doubler plates. She has also had a test idle and a stable voltage has been achieved.

[Duke Blackwood]

[Duke Blackwood]

[Duke Blackwood]

Sorry officer, you must be mistaken, I can't have been doing a 70kmh rolling burnout.... it's only 50cc? Look at the frame....

[Duke Blackwood]

As it sits, behind anglia4's Austin

[datlow]

4 hours ago, Duke Blackwood said:

doing a 70kmh rolling burnout.

video please

[Duke Blackwood]

Hoping to setup a YouTube account soon and put up videos of me gapping Busa’s at the lights etc.

In the meantime, here is my solution to a problem that plagues all of us: where to store all my damn helmets.

On a damn handsome helmet rack.

[Lord Gruntfuttock]

If I was tracing that silhouette for you I'd max out the nose & lips and reduce chin for the "Fuck is that what I look like?" LOLs...

[Duke Blackwood]

Got distracted at shed night, was supposed to be working on the pole smoker but wound up making more helmet racks since I was so happy with the first one. Welded up some go kart chains in a plywood jig and then welded them to some ‘Harley-esque’ non-copyright waterjet cut mounting plates. Lay some brass over one to make it a bit different. 

I’ll be working on the pole smoker again tonight and will have an appropriate update. Otherwise I’ll change the thread name to ‘Helmet Storage Chat’.

[Duke Blackwood]

I like working on hover bikes because the swinging reminds me of Mad Max 2, beyond thunder dome, and that fight scene with master blaster (how hot was Janet Jackson...).

 

Anyway, wheel bearings are all so chooched I can't believe they spun, steering head bearings the same, lock washer comically fucked, larger drive sprocket has been beaver chewing the shifter shaft.. fork seals shagged... top triple tree is tinfoil... front tyre split like a piece of old timber. But in positive news, big carb from China fits good, and the new pads and shoes look to be a good fit too.

[Duke Blackwood]

[Duke Blackwood]

[Duke Blackwood]

[flyingbrick]

On 18/07/2019 at 08:49, Lord Gruntfuttock said:

If I was tracing that silhouette for you I'd max out the nose & lips and reduce chin for the "Fuck is that what I look like?" LOLs...

 You just described me after a shave ffs

[Duke Blackwood]

Stripped more off it over the last week, forks and brakes are completely disassembled, forks are funny, one side is the spring and one side the shock, like an old Buell. I had to make a special spanner to get the steering nut off. It has pushbike style bearings which I'll be replacing with something more heavy duty and I'll make my own triple trees from 20mm Ali, top and bottom functional, not just the bottom as it is currently. Just waiting on fork seals from CHINA and I'll have it all back together. Might have the front brake disc skimmmed.

[Duke Blackwood]

[Duke Blackwood]

Forks are rebuilt now, but not installed, pending the manufacture of my heavy duty triple trees. Front pads and rear shoes replaced. Brakes bled. Hub dressed. Now it's time to make a start on the tank restoration.... I had to shank it open with dads good flathead screwdriver (no key) and was greeted with a combination of varnished rotten fuel and rust.... she's in pretty bad nick. I watched a YouTube video that said to fill the tank with aquarium gravel, wrap it in a blanket and chuck it in the dryer... that would work brilliantly I'm sure, but the old lady would never allow it, and with my recent track record of comical accidents I would no doubt Chernobyl my shed with a fume based explosion. So I filled it with meths and turps and fuel and 60 odd zinc washers and took it behind the shed and gave it hell.... it seemed to work ok. Next step rust converter soak, followed by possibly lining the tank with a fibreglass additive as a sealant? Thoughts?