pbaszxs400

Thanks for the info...don't I need to worry about aluminum shavings falling into the engine?

I’m looking for the best way to do something the wrong way. I have an XS400 special that has the threads stripped on the one spark plug. With the weather clearing, and a lack of parts/ time/ funds I want to find a way to ride the bike without pulling the head. Is there a plug with a slightly larger thread that I can run in? Or, is it possible to JB weld or something similar the plug into place for the season? thanks

It sounds an awful lot like your float height (provided everything else is clean and leak free). The reason that it runs at a high rev is becuse you are "pulling harder" through the carbs, and are able to pull fuel from lower in the bowl. On mine I put a clear tube on the fuel drain outlet at the bottom of the bowl, and loosen the drain screw. If you hold the other end of the tube higher than the carb, you will see exactly how high the fuel is filling the bowls. I usually drain the bowls, then do the tube measurement. This eliminates any error from fuel getting past a drippy needle.

Once I get everything to were I think it should be, I usually put clear fuel line onto the bowl drains and use those as my level to make sure the fuel level in the bowls is not too high/ low.

Does anyone know if the front rotor on an 81 xs400 is interchangeable with one from an 80? I'm in need of one that isn't warped, and it looks like there is one on ebay. Just want to make sure it will work before i buy. Thanks, Pete

I had a similar situation with my 81 XS400. Turns out the starter had a something hanging it up, and it wouldn't turn. Pressing the starter button would only draw current and eventually kill my already weak battery. I had to pull the starter to confrim that it was jammed up.

I have an 81 XS400 special with a starter problem. The old starter was dead, so I bought a new one off ebay. Now when I press the starter, I hear the starter motor spin, but the motor is not turning over like it is not engaging or something. To be honest, I haven’t looked to much into it yet, but should have time this weekend. Any thoughts on where to start? Thanks

Does anyone know what years/ makes starters I can use on an 81 xs400? Mine is bad, so I need to replace. Thanks

I'm based in the US (cleveland, ohio)

Does anyone have a part number and source to get shorter cables for an 81 xs400 special? I put drag bars on it, and now have way too much brake line (needed replacing anyway) and throttle cable. Thanks

Is there anything available for lowering an 81 xs400? A while ago there was a kit we used for old Hondas that relocated the shock mount further rearward on the swingarm. Does this exist for the yamahas?\

Actually, I was referring to the pilot jet that is covered by the rubber plug. It’s right next to the main jet. thanks

I'm cleaning out the green goop and varnish out of these carbs, obviously every jet and orifice is blocked. So I don't damage my pilot jet, can anyone tell me if the hole in the tip of the jet is the same diameter as the holes in the side? I don't want to try and twist through a wire strand that will open the hole up too large. Thanks again

new to the forum, and read some posts on the xs400. I just picked up and 81 from a barn (litterally) and going throught the tear down/ rebuild. For rebuilding and tuning ease, can I run a separate fuel tank (i.e. lawnmower tank on handlebars) without hooking up the vacuum line on the right hand carb? Do I need to cap the vacuum line that ran from the carb to the tank when doing this? used to working on old cb500 carbs....got to admit, these seem a bit foreign to me. The cb's throttle cable actually moved the slide up and down, I'm guessing these slide up based on vacuum? I have all the goodies to get this right (manual, vaccum gauges, dwell meters, etc) Thanks