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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 Addict Top Contributor

    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 Addict Top Contributor

    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 Addict Top Contributor

    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 Addict Top Contributor

    @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 Addict Top Contributor

    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 Addict Top Contributor

    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.
  11. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    The frost is definitely on the pumpkins here in New Jersey, but there have been a few days where the temperature is high enough to paint parts that are already clean and de-rusted. I do have a few chrome parts where the top finish is completely gone, so I have done some experimenting with paint filling the bare metal areas in a way that ends up looking okay to my eye. I ended up using a four step spray paint process of primer/gloss black/metallic paint/clear coat.


    I think it came out alright, but the clear coat does dull the metallic finish somewhat. The clear is necessary though because the metallic isn't really rated for direct outside exposure long-term. I am interested to see how long this stuff lasts.
  12. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    It has been a while since I last updated, but a pretty big milestone has been reached. I have finished all of the projects that were taking up space in my shed and the weather was good, so the tarp came off the bike and I pushed it up inside today.
    Bike in Shed 1.JPG

    Bike in Shed 2.JPG

    It will be a bit tight working in there, but inside is so much better than outside. I will move onto getting the suspension off and the engine out of the frame and on the bench. I also pulled the output sprocket cover off to loosen up the sprocket nut and discovered an old mouse den underneath. I can't see all of the wiring in there clearly as there are a lot of caked on mouse turds on the case and cover, but I hope that the mice did not chew up the wiring in there as part of their residency. Little bastards!
  13. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    The wheels are off. The linings on both brakes are completely unbonded from the shoes, so new ones are on the list to buy. Next will be suspension removal and inspection followed by removal of the engine.

    Wheels off.JPG

    Brake condition.JPG
  14. AmbientMoto

    AmbientMoto XS400 Addict

    Good progress. I also use Evapo-rust; it's always worked well for me.
  15. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    Thanks @AmbientMoto - I am trying to move it along so as the outside temperature warms, I can be in a position to paint. My Metal Rescue rust remover will be making it back onto the scene shortly also as it works better in warmer temperatures.

    Speaking of spring temps, it was really nice and warm today so I spent a bit of time out in the shed and got the front and rear suspensions off of the frame and disassembled.
    Forks Apart.JPG

    Swing Arm.JPG

    In general, everything looks pretty good. The spring measurements were fine and there was zero play in the swing arm - so everything is in spec. After draining the oil, there was a bit of black sludge in the bottoms of the forks and one of the fork seal clips was rusted away. I see that those clips are hard to come by, so I will probably just fabricate some new ones myself. The engine is the only thing now left in the frame.
    Frame with Engine.JPG

    I am pretty excited to pull it, but there are so many parts laying around near the bench that I need to spend some time to clean, degrease, bag and label everything before I can make another move. The engine pull should be pretty straight-forward at this point, and I hope to have it done before the weekend.
  16. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    Still cleaning. I hope to get to the engine this afternoon, but we shall see how that goes. I did get some parts yesterday and used the UNI filter foam to rebuild my air filters.
    UNI Filter 1.JPG

    I was going to just buy some new ones, but after looking at how well these are constructed, I couldn't bring myself to throwing them out. These things are solid, and I want to thank the Yamaha engineer who designed them! I can't believe that the project manager or cost accountant didn't nix these in favor of some cheap plastic frames. This may be a budget bike, but it certainly has some non-budget touches.

    So the filters are oiled up and back in their air boxes and ready to go back on the bike, whenever that happens.
  17. xschris

    xschris XS400 Guru Top Contributor

    Make sure the foam is the same density as the stock foam. Also these should not be oiled this will restrict airflow greatly. The stock filters just get washed with soapy water or just blow them out with compressed air. High flow makes a OEM equivalent that works almost as good as the stock ones do. Those are cheap around $15-$20 a piece and last a very long time.
  18. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    @xschris - Thanks. I did look at the original foam (what was left of it) and tried to guess at the density, but a shot in the dark is all it is. Thanks for the lead on High Flow and the personal recommendation for the product. I will keep that in mind as I proceed forward and perhaps get some to try as they are pretty inexpensive.
  19. xschris

    xschris XS400 Guru Top Contributor

    The Yamaha ones do work the best but the high flow ones are as close as you can get.
  20. CaptChrome

    CaptChrome XS400 Addict Top Contributor

    The frame is stripped, and the engine is on the bench ready for some cleaning.

    Engine on bench.JPG

    The plan is to replace every seal, check the top end and get it looking presentable.

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