CaptChrome

Surprising, right? I can ride this bike through a tank plus and still feel great afterwards. I was definitely not expecting that...

Bravo! I guarantee that every attempt after this will be better, but you will never get good unless you start in the first place and a...

If this ^^^^ doesn't help, check the spark timing and advance. Lack of balls across the rev range is also a sign of a retarded spark.

The crankcase to carb intake line is mostly to reduce emissions. It is not a reed valve, but simply an opening straight to the crankcase...

Regardless of the plugs right now, the mix screw position and the hanging throttle comment sort of point to a lean condition and maybe...

Do what tstidham suggested first, but what oil are you using - is it rated for use for a motorcycle with a wet clutch? If the oil is not...

Right on! +1 on this. Prep has to be extremely thorough for the sealer to last and work. I believe too many think sealers are the magic...

Yup. They sell only OEM Yamaha parts - same as the dealers. I have used them all of the time after price shopping and never had a bad...

Welcome. You might get Yamaha cables to work from a different style of bike. I originally had buckhorn bars on my '81 XS400H Special...

You know, I forgot to mention one thing. People have had some luck opening up the TCI, cleaning them and repairing the solder joints...

Good move. The only way I know of to test what is up at this point is to swap in a known good TCI. If you know of other DOHC XS400...

They tend to idle higher when warmed up, but it could be the pilot jet is bigger than it needs to be. A couple of questions to narrow it...

Welcome. Either the TCI is not connected properly or not working or the pickup coil is not sending signal to the TCI. I am assuming you...

Welcome. While I don't have the DOHC bike, I have had my SOHC bike starter apart and can offer some opinions of how you might proceed...

Build a hidden fender hump into the seat pan to allow for the rear wheel to have full travel. It will also allow you to get the look you...

So, here is the link I was thinking about: https://www.xs400.com/threads/81-back-running-now-what.20446/

I second using the on-line catalogs. They also list what other bikes the part is used in which helps to broaden your search when trying...

There has been a recent discussion of this very thing within the last six months or so. I recall @JPaganel responding to it. Let me see...