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79Gs400 Total Rebuild

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    79Gs400 Total Rebuild

    Hey guys,

    I’ve got a couple of questions about a 79 gs400 rebuild that I have started:
    -is using a vapour degreaser to clean a completely disassembled engine prior to rebuild a bad idea?
    -any recommendations for clear coating the engine? I’d rather do that than paint it if I can
    -any recommendations for buying braided lines? In Canada? Elsewhere?
    -any important engine (or general) rebuild no-gos?

    I am new here, but have recently picked up a 79 gs400 and a 79 gs425 for cheap, neither of which are anywhere near running atm. The 400 frame is registered out of province, and I have no papers for it, but has a solid looking engine that I plan to completely strip, clean, rebuild then plug into the 425 frame (better shape and also registered here in BC). I will also have to rebuild the carbs, airbox, brakes, and probably the harness. I was thinking about cutting the pipes and frame, adding pods, and rejetting the carbs, but I am going to hold off at least until it is on the road stock-ish —I know that this might not be a super popular choice, but a this point I was saving these bikes from going to the scrapyard so I thought I'd try it out down the road.
    I have experience working on crappy old pickups and an old honda bike, but this will definitely be my biggest engine project to date, so any advice (engine or general rebuild) is welcomed. I will be doing pretty much everything at home with my trusty socket set, but have access to some other tools and machines at work.

    The 400 is now pretty take apart, and as a next step I am looking at how I will clean the engine. Any tips? Engine is out but still whole right now, as I wanted to come up with a plan before splitting it open. Ideally I will clean it inside and out, because although it turns over I have no real idea of what its guts look like. I could get access to glass bead (probably a bad idea on aluminum), plastic media blasting, a vapour degreaser, or just plain old sweat and scotchbrite. Any and all wisdom is appreciated.
    Note that I plan to rebuild the engine mostly following a Clymer manual.
    I plan to either clean the gas tank electrolytically, or also using the plastic media and degreaser.

    I posted here because I have questions of all types, and am just starting out —I will ask some specific questions in other threads. Will keep you guys updated with pics.

    Thanks
    Attached Files
    Last edited by Guest; 05-08-2018, 02:15 PM.

    #2
    IMG_4680.jpg

    The 425 bike

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      #3
      IMG_4763.jpg
      the 400 looking a little skinny

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        #4
        IMG_4766.jpg
        To be cleaned + loved

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          #5
          Will post better pics in the future, things are cramped with renos going on now (note circular saw in background )

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            #6
            I'm pretty sure the cases and jugs are painted right from the factory, they are on my '82 450. I've had aluminum heads glass beaded on another bike in the past and they looked quite excellent, darn near white color so I put them on with no paint or coating. As to the side covers, your best bet is to polish them, you might need some very fine sandpaper to start and keep working finer. I've never tried it myself but have thought about "graining" covers before with a wire wheel or Scotch Brite. You'd have to do it in exactly parralell passes but if you could figure out how to build a some sort of jig, that may do the trick.
            1980 Yamaha XS1100G (Current bike)
            1982 GS450txz (former bike)
            LONG list of previous bikes not listed here.

            These aren't my words, I just arrange them

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              #7
              Thanks for the feedback LAB3. I might go for just lightly beading the heads, although I am not looking forward to fighting a constant battle with oxide ... Do you have any pictures of your beaded headers? Still not sure about covers either, I'll have to sleep on that one some more

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                #8
                image1.jpg Gas tank stripped, carbs apart for cleaning, engine scrub down started. Plastic bead blasting is a glorious thing

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                  #9

                  fresh-beaded tank

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                    #10
                    image3.jpg
                    dirty old carbs

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                      #11
                      That would be the heads as in cylinder heads, not headers on a cone lower shovelhead. Cases, jugs and rocker covers where already painted black, had the valve seats replaced with hardened ones and stainless valves, the guy who did the rebuild on them also did the glass beading. Had the bike about three years after the rebuild and they still looked good. No pictures, that was back in the 80's.
                      1980 Yamaha XS1100G (Current bike)
                      1982 GS450txz (former bike)
                      LONG list of previous bikes not listed here.

                      These aren't my words, I just arrange them

                      Comment


                        #12
                        For SS braided brake lines in Canada: http://rennsportautoparts.com/

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