Author Topic: 1978 Suzuki GT500  (Read 1674 times)

July 12, 2013, 08:55 PM #0

Rx7rotary Offline

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So I guess this is going to be a bit of a story as well as potentially a build thread....

I've always loved bikes. I can remember riding with my dad and my uncle as a kid, then messing around on dirt bikes, trikes and quads when I got a bit older.
When I was fairly young my uncle was in major accident and almost lost both his legs. This probably had an influence, but my parents always discouraged me from buying a motorcycle. They also scared the hell out of me at that point.

Over the past 10 years, even though they still scared the **** out of me, they have been in the back of my head... Thinking back to my wild fresh out of high school phase, its probably a good thing I haven't owned one until now.


Anyways, for a year or so the idea had been growing stronger and stronger. It was last fall when I started to seriously consider buying a bike. I am always watching kijiji and the forums but I could never justify spending the money. Last weekend I went over to a buddies place to look at an engine, and he had 3 café bikes in the works. One freshly built from an old XS750? (which I remember seeing in his backyard and thinking it was awful). It was now one of the sexiest things I have ever seen. I couldn't resist any longer and decided I would look for a cheap project.

Tuesday rolls around and I decide to email a guy in grand beach about this old Suzuki GT500. He still has it so I arrange to come out Thursday and look at it.
Last night me and my buddy hop in his truck and roll out to see the beast. It was in pretty rough shape, but I just saw the potential.

I offer the guy $150 and he accepts! So we load the bike up and off we go. Even though it is pretty haggard I am pumped.
We get back to my house about 9 PM and unload the bike. It is dirty, missing parts, and has the most awful seat I have ever seen in my life but its my bike! MY VERY OWN BIKE!

I present to you, my 1978 Suzuki GT500 (yep, air cooled 2 stroke!):








So after a good night sleep I went into work today but just couldn't wait to get off, go home and dig in. Overall the day went quick but it started to drag by late afternoon so I slacked off and printed these:






Got home, tore it down a bit to assess:





Its actually a damn solid foundation!!!
Tank is a bit rusty inside but I think it is usable! Seat is in the trash, and a custom one is being planned. Carbs are in great condition but will get a rebuild. Will need a bare minimum of coils, wires, plugs, foot controls and sprockets (looks like the chain spun around the rear one the last time it was running).

I really didn't have high hopes for the engine until I saw the sprocket, and after a quick compression test both cyls were reading 130+ psi. That's a good sign! Fingers crossed that the gearbox isnt borked.

I am not sure what the forks are from, but it has dual front discs. Through some reading, the GT500 never came with these. The brake lever is also slightly different so I have some investigation to do. Forks will also need new oil and seals.


Does anyone know where I might go digging for some old zuki parts? Mainly the foot controls... As long as I find something similar I don't mind getting crafty. Not looking to go all out stock so I would prefer to find something local.. Old dirt bike parts might even work!


I don't plan to do very much just yet because the bike needs a TOD. I contacted vehicle registration but will need to go fill out a statutory declaration to see if I can register the ol girl.

If everything works out I plan to build it up borderline café style. I plan to do all the fabrication myself and have a pretty clear picture of what I want out of it in my head!

As soon as I hear back from vehicle registration or find some cheap parts to repair it there will be updates.

Cross yo fingas!!! :)

Last Edit: July 12, 2013, 08:57 PM by Rx7rotary
Shiftin gears, eatin cheeseburgers

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    1978 Suzuki GT500
    « on: July 12, 2013, 08:55 PM »

    July 13, 2013, 10:39 AM #1

    Sahba Offline

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    http://www.oldbikebarn.com/1977-Suzuki-GT500

    They don't seem to have alot specifically for your bike there, maybe eBay will have better results.


    Best of luck.
    I've been riding my 79 Kawi KZ400 around lately again and I love old bikes, other then when they stall and wont turn back on for ya

      July 13, 2013, 10:55 AM #2

      99blackSE Offline

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      I came close to buying a '78 Yamaha 250 2-stroke a couple weeks back.  This should be a fun machine with some pretty good balls when you're done.
      2005 Grand Prix GTP Comp G
      2001 Silverado Z71 - workhorse
      2011 CBR 250RA

        July 14, 2013, 04:22 AM #3

        Murphenur Offline

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        x2 on the 2-stroke... want one as well.  love the kawi triple 2-stokes, but these suzukis can make good power.
        1995 Mercedes E320 Wagon

        2007 Audi S6

        1959 Mercedes Benz 180D

        1980 Honda CX 500 Cafe

        Sponsored by your mom and dad

        scrapesloths

          July 14, 2013, 11:23 AM #4

          boostfreak Offline

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          Sick deal! So did you get it running or just compression tested? Compression numbers look good. Mikuni VM's are very good and desirable carbs, whenever I have major carb troubles I just bolt a set of those on.

          Like I said on Heights Ebay is your friend, and those look like flipped around 750 forks/brakes. Cool

          Hell yeah



          Now I want one.
          BNRJAMZ
          '13 Fiat 500 Turbo
          Originally posted by: Igor
          i don't know why you would want to say its an sti, especially around people that know what they are looking at. like buddy, its a wrx, who cares. personally i find it insulting that he calls it an sti

            July 14, 2013, 09:07 PM #5

            Rx7rotary Offline

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            No, its not running. It is missing coils, needs a battery and a few other things.

            I love the simple Mikuni Carbs. Have some experience with VMs from my snowmobiling days. The carbs I pulled off look fantastic so far! Will do a once over before I put it all back together though.

            Really hoping everything works out. Plan to file the papers regarding the TOD tomorrow and hopefully I will hear good news so I can start really wrenchin. :)
            Shiftin gears, eatin cheeseburgers

              July 14, 2013, 11:11 PM #6

              Faken Offline

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              subscribed! This is going to be awesome!
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              [Mar 26 13:45:26] Igor:hearts before parts

                July 15, 2013, 09:10 AM #7

                Rx7rotary Offline

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                Papers filed. Now all I can do is hope that itsss goooood!
                Shiftin gears, eatin cheeseburgers

                  July 15, 2013, 03:38 PM #8

                  Rx7rotary Offline

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                  That was easy as pie. TOD in hand.

                  Time to get started! wooo
                  Last Edit: July 15, 2013, 03:44 PM by Rx7rotary
                  Shiftin gears, eatin cheeseburgers

                    July 17, 2013, 07:39 PM #9

                    Rx7rotary Offline

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                    Today I pulled the ol VMs apart. To my surprise everything looked amazing. No crud, sludge, or blockages!  The only thing I will need are the little springs that clip on and push on the floats. Might as well order a pair of mikuni needle/seats and call it a day.

                    Got some amsoil for the gearbox, so I think all I really need to get it fired up is a battery, coils/plugs/wires. Have a feeling the B77HC plugs aren't going to be the easiest to find, hoping I can dig up a couple old points coils and make it work.

                    I am going to have a bit of fun straightening out the wiring, but if this thing runs, the rest of the build will be a blast. :)



                    Shiftin gears, eatin cheeseburgers

                      July 21, 2013, 01:54 PM #10

                      boostfreak Offline

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                      Have you checked the points yet? I'd start there if you have no spark.

                      You can also ohm your coils to see if they are any good. I want to see this thing
                      BNRJAMZ
                      '13 Fiat 500 Turbo
                      Originally posted by: Igor
                      i don't know why you would want to say its an sti, especially around people that know what they are looking at. like buddy, its a wrx, who cares. personally i find it insulting that he calls it an sti

                        July 22, 2013, 08:32 PM #11

                        Rx7rotary Offline

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                        Points look brand new! Might need to be gapped but from what I see it should definitely run. It needs coils simply because it didn't come with any, haha. I am thinking I might pick up some old mercury marine coils as they appear to be a solid/cheap solution. I am going to try to get the rest of the parts together ASAP.

                        Spent the weekend at the cottage so I didn't get much time to wrench on it, but on Friday I went down and saw Joe at Canadian Motorcycle. They actually had a T500 in the back that had a bunch of parts I needed, but no coils.
                        Picked up some spark plugs, a footpeg, rear brake pedal, shifter, and a seat that needs some new upholstery.

                        Thought I was in for some trouble when I attached the shifter and it was locked up solid.
                        Turned out the there was a serious assembly error so I pulled the clutch basket and re-aligned the shift gear. BAM! Gears came back (sigh of relief) and feel great. Judging by the vice grip marks on the shaft, there were some seriously ghetto attempts made to fix things. I have my suspicions that the '75 motor that came in the bike never ran in this frame!

                        Petcock was a little sticky so I pulled it apart, cleaned and lubed everything up. Took another look at the tank and it is in great shape internally. Checked the wear on the clutch plates when I was under the cover, and they look beautiful! De carbonized the baffles in the exhaust and did a little more cleaning. I am quite excited, and have high hopes that it will run again soon.

                        As soon as I find time to pick up some coils I will attempt to fire it up. I will make sure I have a camera rolling so everyone can see the weed whacker smoke out my neighbors. Keep your eyes peeled for updates, I hope for some exciting ones soon!

                         :banana:






                        Last Edit: July 22, 2013, 08:34 PM by Rx7rotary
                        Shiftin gears, eatin cheeseburgers

                          July 22, 2013, 10:51 PM #12

                          TwoFourDee Offline

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                          Love it Alex.  Can't wait to come check it out
                          You can delete my posts but you can't delete my dignity.

                            July 25, 2013, 12:56 AM #13

                            Rx7rotary Offline

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                            Found a set of oldschool 12V points coils with a built in resistor for a variety of old automobiles on rockauto. Figure they will be as good as any... and the price was right so I ordered them.

                            I also decided to re-upholster the stock seat I bought at Canadian motorcycle to test out my leatherworking skills. The plan is to eventually find some rearsets, drop the bars, redo the seat/tail and café the **** out of it but it will be staying stock for the meantime.

                            I repaired the old nasty seat foam with some 2 part urethane foam, and made the patterns for the new cover. Hope to start sewing it up this weekend once I nail down the best way to do a pleated center section and piping. The pan needs some serious love though.


                            The real test will be if it runs when I install the coils... If it goes smoothly, it will come back apart for some fresh paint and the final parts order. I am quite hopeful! :)


                            Shiftin gears, eatin cheeseburgers

                              July 25, 2013, 02:02 PM #14

                              boostfreak Offline

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                              • boostfreak is working their way up.boostfreak is working their way up.boostfreak is working their way up.
                              Simple test, hook everything up, pull a plug out and ground the electrode, open up the corresponding set of points and you should have a spark at the plug every time.

                              Good luck, should sound cool starting up lol
                              BNRJAMZ
                              '13 Fiat 500 Turbo
                              Originally posted by: Igor
                              i don't know why you would want to say its an sti, especially around people that know what they are looking at. like buddy, its a wrx, who cares. personally i find it insulting that he calls it an sti

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                                1978 Suzuki GT500
                                « Reply #14 on: July 25, 2013, 02:02 PM »