I had one back in the day. It was a good bike and that 3 cylinder was smooth but they do have some common problems.
The 76/77 had points and the carbs were quite hard to set up. The 78-> bikes had electronic ignition and upgraded carbs and were much easier to set up and stayed in tune. it’s worth doing this swap on earlier bikes.
Like a lot of Yamahas, some developed second gear problems. They could be shimmed to take out the slop but unfortunately it means splitting the cases.
The shaft drive was pretty reliable but the very early bikes had problems with leaky seals which should have been fixed under warranty. Same with Valve Guide Seals. it was addresses on later bikes.
As has been said check the tank for pinholes. If there is just a bit of surface rust on the inside it could be cleaned or sealed, although 70’s Yamaha tanks are much better that 80’s tanks.
I think it would be an interesting project to tinker on.
The 76/77 had points and the carbs were quite hard to set up. The 78-> bikes had electronic ignition and upgraded carbs and were much easier to set up and stayed in tune. it’s worth doing this swap on earlier bikes.
Like a lot of Yamahas, some developed second gear problems. They could be shimmed to take out the slop but unfortunately it means splitting the cases.
The shaft drive was pretty reliable but the very early bikes had problems with leaky seals which should have been fixed under warranty. Same with Valve Guide Seals. it was addresses on later bikes.
As has been said check the tank for pinholes. If there is just a bit of surface rust on the inside it could be cleaned or sealed, although 70’s Yamaha tanks are much better that 80’s tanks.
I think it would be an interesting project to tinker on.
