What am I getting into?

I am going to guess that no, they are not. According to another site with photos (partsnmore) the 76-81 use a different filter than the 82-84. That site is advertising one filter for 77-83, which, to me, doesn't make any sense. With the lack of photos I would not risk it without confirmation from someone else.

From here: http://www.partsnmore.com/parts/yamaha/xs400/ you can filter by year and see the pictures. I've ordered from here before as well.
 
That is the only place I have ever seen with a reasonable price. I don't trust places with no photos. What condition are your air filters in anyway?
 
You might be able to rip off the foam and replace it with something else. My stock ones appear as though a thin strip of material will do the trick. There is also the whole adventure of using pod filters and jetting...

I just went for pods and aftermarket exhaust because it's so cheap. I was not willing to spend 300 on an exhaust and 50+ for air filters.
 
Yeah, I didnt really want to get into Jetting just quite yet. Im going to keep poking around.

Ive considered rebuilding my current filters, then the end plates fell off. Ha!
 
Probably, and I only say that because I have heard these bikes tend to run on the lean side in stock form. A pair of jets is only 6 bucks or something, so 12 + shipping for mains and pilots.

The end plates fell off my stock filters too, but if you're willing to fix and modify them you only need to pay for some foam. If you "upgrade" to pods you'll have a modern part that can easily be replaced. Oem parts are only going to get harder to find over time. You might not keep the bike for long or you might care about restoring the bike to its original form. It's really just a balance between priorities and what you're willing to spend. Installing the jets is trivial, but tuning will take a little more work, but it is nothing you can't handle.
 
I admire your persistance Will, hell I decided to rip down my bike and start over because I was sick of how it ran...tuning is something I sometimes dont have the patience for
 
No one could say with any certainty exactly what size you need to get it running perfectly because everyone's engine is going to run a little different. From other people's experience with a stock-ish exhaust and just pod filters 2 sizes up on the main jet and 1 size up on the pilot jet will probably be fine. I do not know what sizes your 81 has in it to begin with and I am hesitant to quote anything from my Haynes manual because it listed a lot of wrong sizes for my year. Pull out your jets and get the numbers off them; that is, unless someone else can tell you with absolute certainty.

After riding around on my bike yesterday for about an hour and really letting it get up to a hot temperature I could probably go up another size on my pilot and raise my slide needle for a smoother transition from 1/8th throttle back to idle. The main jets seem easier to sort out than the pilot or slide needle.

After considering tuning it may be better for you to try 2 sizes up on the pilot. You can essentially lean out the pilot circuit as much as you want by closing the fuel mix screws, but you can only richen it so much by opening them. Maybe buying both sizes would be a good idea because shipping costs more than another set of jets.
 
Thanks so much dude. I appreciate the quick response. I'm grabbing the rest of the service parts, just thought Id grab those while I was here.

Alrighty! Got a new helmet (No way Im wearing a $1200 Sparco Helmet on a $200 bike), new goggles, oil, filters, brake fluid and chain lube.

It's going to be a good Sunday!

Now, Im waiting for brake shoes, MC Rebuild kit, and the oil screen.

Then it's time to get my Permit!
 
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Felt like digging into the brakes today. Now that Im looking at things, the rears dont look too bad.

I was thinking a small clean and reassemble for these. Looks like theres plenty of pad left...

IMAG0778.jpg

IMAG0777.jpg

IMAG0776.jpg
 
I was out for a ride yesterday and it turns out that my exhaust developed a pretty serious crack. On the right hand pipe, right where the H-Pipe meets it, the pipe ripped almost all the way around.
Well, a quick stop at the welder's (Luckily, he wasnt busy) and we're good to go. The loudness is dampened, my headache is gone, and we're back in business. The weld looks like a wort on the shiny piping, but, hey, it's no show bike.

billy.jpg


Oh, and I rode it to work today!
 
Awesome. I am glad you decided to pick this thing up. It is already serving you well. I am battling with myself right now as to how much I want to "restore" the bike as opposed to just doing the minimum safety upgrades and maintenance to get riding asap. I have to do steering bearings, fork seals, rear swing arm, and rear shocks already, so I suppose tearing it down a bit more wouldn't be much extra work. Hm...

What do you have planned next?
 
bc, That swing arm I sold you does have nice bronze bushings in it, and that axle is the greasable kind

think your 78 still has the plastic ones...(not too sure)
 
I am going to guess it does; This bad ass 2e has absolutely no options; drums all around and no electric start :)
 

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