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81 XS400H – putting the Trusty back into Rusty

Discussion in 'The Garage' started by CaptChrome, Aug 19, 2021.

  1. Buddha

    Buddha XS400 Addict Top Contributor

    Thanks for the info xschris, the only product readily available for me locally is red and tacky grease, I'll have to settle for that I guess.
  2. Buddha

    Buddha XS400 Addict Top Contributor

    Thanks for the info xschris, the only stuff readily available locally for me is the Red and Tacky grease. I may have to settle for that.
  3. CaptChrome

    CaptChrome XS400 Enthusiast

    A few more items got done in the last few days on the electrical system and the carbs. I did get the tops off of the carbs and took out the diaphragms. Both were pliable and without cracks. Quite the surprise after being in there for forty years. I did as xschris suggested above and greased them up before putting them back in and storing them.
    Carb Diaphram1.JPG

    I also removed the remainder of the electrical components, wiring harness and most of the cables. The front brake cable and tach drive both will have to be replaced. I still need to get the clutch cable off and will do that when I start pulling the engine. I will go through the electrical system on the bench in the near future and have ordered a set of keys for the main switch. One thing I did get to test was the gages.

    The tach drive cable was completely rusted and I chucked a bit of one end into my drill and spun both the tach and speedo to see if they were mechanically intact - they both worked! So I intend to use them even though the sun has changed "red line" on the tach to "white line" and the 55mph warning is no longer.

    All-in-all two pieces of good news. Next up is to hook up the majority of the electrical system on the bench and function test it to see what's what.
  4. CaptChrome

    CaptChrome XS400 Enthusiast

    Question - is there any recommended maintenance needed to keep the mechanical tach and speedo operational over the long-term? The manual doesn't mention a thing, and I am tempted to put a drop of very light machine oil into the drive of each one. Has anyone peeled off the bezel and looked inside to see how these might hold up?
  5. CaptChrome

    CaptChrome XS400 Enthusiast

    Lately I put my wiring harness into my wash tub and cleaned it with water and some dish soap. After it dried I re-wrapped any areas that were marginal or torn. I did have some plugs that were sun scorched and cracked, so I replaced a few that looked like this:
    Broken Plug.JPG

    I also noticed that my turn signals are not all the same. One is shorter than the others, so I assume it is from some other Yamaha of the same era:

    In the end I will probably not end up using these and replace them with something with a lower profile. Finally, I set everything up on my bench and ran an integrated function test of most of the harness. I couldn't test the charging system, ignition or the starter motor, but at least I could wring everything else out without crawling around the bike:
    Bench Test Harness.JPG

    I had a lot of corrosion in the connectors to chase and clean, and the horn and start button took extra effort to get them back into operation, but in the end everything works except for one burned out warning bulb. This also tested my new fuse box, headlight and keys. I tried the auto cancelling by spinning up the speedometer with my drill and that works as advertised. I don't think I will get to use that feature if I swap out the turn signals, but it was fun to see it work.

    Next up will be moving the bike into my shed and get to engine removal, frame cleanup and suspension/wheels. That, however, will have to wait for two other big projects that are in the queue ahead of this one. So it will be on to parts procurement and little odds and ends if I can fit them in.
  6. xschris

    xschris XS400 Guru Top Contributor

    The 80-82 sohc bikes used shorter front signals.
  7. CaptChrome

    CaptChrome XS400 Enthusiast

    @xschris - great info. Something must have happened in the headlight "area" as the bucket that came on the bike is a big 7" unit wedged in between the mounting brackets. The bucket is a Yamaha bucket, so some parts of convenience must have been used to try and put a headlight and turn signal back in place without having the correct parts
  8. CaptChrome

    CaptChrome XS400 Enthusiast

    Even though this project might be on the back burner, it is definitely not dead, so here is an update. The biggest issue that needs to be addressed pretty much everywhere on this bike is corrosion, so I have be trying out some ways of removing rust. I have heard good things about Evaporust and Metal Rescue which are liquid products that you immerse rusty parts in. These products only remove the iron oxide and not good surrounding metal, are supposedly safe for other materials like chrome and aluminum and are environmentally safe to dispose of locally. I bought some Metal Rescue and have been using it on a variety of parts with good results. The stuff can be used over and over, but it will turn dark purple the further it is used. I don't know exactly how long it will remain effective, but the first gallon shows no signs of quitting on me.

    It takes 24 to 48 hours to clean things up, but as I have been working on other things, it has been nice to just drop in some parts every so often and walk away. for a couple of days. Here are some before and after picks including some chrome parts.

    The only downside with this stuff is it is somewhat pricey - a gallon costs about the same as a case of beer that I buy, but I figure I would have drank two cases of beer so far if I had been removing the rust by hand, so this stuff is a win in my book.
  9. Buddha

    Buddha XS400 Addict Top Contributor

    Ha ha ha ha, my kinda thinking about me an Capt,n Spiced. But sometimes he wins the war........
  10. CaptChrome

    CaptChrome XS400 Enthusiast

    Go with what motivates you Buddha!

    Honestly, I have not reduced my beer budget for this build after buying the rust remover; the calculation is just my way feeling better about using the high dollar stuff. I can assure you that I will still consume the same amount of beer whether wire wheeling rusty bolts, or just standing around looking at a tray of parts soaking.

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