1981 yamaha xs400?

I just purchased an 81 Yamaha XS400 Special, and I am planning on turning it into a cafe racer styled bike.

The aesthetic parts of the project are easy to find, things like fairings, seats, etc. but where can I find performance parts for a bike this old?

Also where should i start with upgrading the bike?

Are there any trouble spots with this specific model?

Thanks for any help.

1981 yamaha xs400?bmw

dunno, but try http://www.mikesxs.net/ or http://xs400.blogspot.com/ for info, they seem to have their sh1t toghther

1981 yamaha xs400?free adware remover

If you truly want a cafe racer it would be cheaper in the long run to get a different motorcycle. The XS400 were decent bikes but when you add up the cost of all of the things you will need to replace it would be chaper to buy a newer motorcycle that already has better performance than a XS400 will even have, even modified. And modified motors don't usually last as long as a motor left stock.
their a bit heavy to make a decent cafe from but if you must brace the frame remove airbox,rejet carbs to suit 2/1 exhaust .regrind cams,lighten the bike where ever posible including the wheels.only bad weak spot on these is the valves i don't think you can buy them any more. it'l never beat an rd/rz but it mite be fun trying..
The special was not a sport bike in the first place but did have a good engine. Performance can be improved by doing the top and bottom end, in take and exhaust sides. Then to match the performance you will have to upgrade suspension front and rear and brakes also. Add cost of each and its not worth all the trouble. Get a Honda 400 VFR or similar and do the mods on body parts for a `cafe racer`styled bike