Yeah, I can fix that

[SoCal250]

Now I've seen it all!
I was looking over some RD400s on Ebay when I came across this '77 for sale. Noticed this odd piece of copper on the oil pump and then found an explanation in the description.

"I noticed that the exhaust began to have less of a blue tint to it, so I added a simple piece of crimped ¼" copper tubing about ¼ inch long to the two cycle oil pump mechanism that improved the amount of oil getting to the fuel mix. Whether this was a cure or not I don't know, but I got more blue smoke and that made me happy. Since I am no expert,it might need a tuning once you take delivery, but it should start,idle and perhaps you should get to ride it right away."
https://www.ebay.com/itm/1977-Yamaha-RD400/324192002686

[m in sc]

[rodneya]

That is quite the sales pitch.

[Czakky]

WTF? Also. Who replaces 30 year old tires and decides to let the tubes ride?