Honda GB500 thread

Discussion in 'Old's Cool' started by Spurlock, Aug 27, 2016.

  1. solidol

    solidol Adventurer

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    I was thinking about that as a safety measure but if I remember right bolt would be already out on the left swing arm before its head hits the muffler. Maybe not, will find it in an hour :)
  2. solidol

    solidol Adventurer

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    Can any of you guys post a picture of your speedometer gearbox installed? GB has casting with only one lug (not two where you align it with a fork leg lug in the middle) but I assume it needs to go behind the fork leg lug to prevent gearbox from spinning with the wheel.

    I have adjusted the chain tension too. I don't use tension measurement tool but just sit on the bike to preload it with mighty 160lb :) and check tension in the middle of the chain to see how much slack it has. I think manual says somewhere around and inch but I'm a always struggling to make it perfect.
    [​IMG]
  3. Spurlock

    Spurlock Long timer

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    You are right, the speedo drive lug goes behind the fork lug. Once the axle is tight it can't rotate, but the lugs are useful to position the drive so the cable comes off at the right angle.

    Don't overthink the chain tension, just weight the bike so the swing arm pivot is in line with the rear axle and countershaft (tightest chain point) and make sure you can move the chain at least 3/4" at that point. Looser is better than tighter. The O-ring chains are sometimes so stiff that you need to grab the chain and pull up and down firmly several times to straighten out any kinked links to see the true slack.

    -Bill
  4. solidol

    solidol Adventurer

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    Thanks Bill, much appreciated. Off to figuring out intermittent blinker failure (I remember you have suggested cleaning switch contacts). Then flushing brake fluid (and maybe master cylinder rebuild upon inspection). And removing air pump next week once block off places show up. Desperately need to go for a ride as I've been mostly checking everything at my spare time. Greatly enjoyed it though. Thanks for everyone's help here.
  5. solidol

    solidol Adventurer

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    It helps not to work on it (bike especially) when a bit sick and with limited lighting. I was going off of the idea to prevent from rotation but once started tightening axle shaft I did notice gearbox was getting pressed in and not rotating. Also I think it wasn't installed right as speedometer cable wasn't sitting right. But I may be seeing things at this point. Today after looking at it again but with daylight and clearer head what I see is that aside from all that I mentioned if you look at the casting shape for that lug it's at 90 deg on one side (that should be used to press against fork leg lug) and other side is curved which cannot/should not be used to handle pressure/force. So there is only one way to use it anyway :)

    #still working on cleaning some grime and touching up few places on the swing arm where paint has been chipped.



    [​IMG]
  6. Spurlock

    Spurlock Long timer

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    Get out there and ride while this crazy warm weather holds!

    When cleaning the blinker switch contacts also clean and lubricate the lock-on/cancel mechanism. They get sluggish from old dried up grease. You can probably clean the contacts with just a couple squirts of contact cleaner while working the switch back and forth. For the lock/cancel mechanism just remove the single phillips screw that holds the lever in place, being careful not to lose the washers on either side. Clean off the old grease and apply new, reassemble and you will probably find the switch works again and is also much easier to operate.

    Cheers,

    -Bill
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  7. solidol

    solidol Adventurer

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    Thanks again, Bill. Been a bit under the weather and figured it's better to take it easy and work on the bike and handle small things.

    I have used these wheel weights and upon closer inspection looks like I have few spokes to clean up from rust pitting and such. have anyone used EvapoRust?

    https://www.evapo-rust.com/product-info/[​IMG]
  8. Spurlock

    Spurlock Long timer

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    I find Evaporust works well but only for parts you can submerge and soak for a while. When just brushing it on parts it dries before it has a chance to work. Lightly tarnished spokes usually polish up nicely with metal polish and elbow grease. It's tedious but the results are worth it. Stubborn spots can be rubbed with 4/0 steel wool first. Have fun...

    -Bill
  9. AllenS

    AllenS Adventurer

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    I have used Evaporust many times. It is a stable in my shop. The way it removes rust is a chemical reaction and it does not harm aluminum or chrome. In face I drop small parts like the chrome fork cap nuts that have tiny rusty pits into the chemical and sometimes let it soak for hours or overnight. No harm to chrome but the rust is dissolved.

    I have switched to Rust911 brand. The sell a concentrate. One gallon makes 16 gallons of solution. I use it too fill rusty gas tanks. Let it sit a couple days and the rust is dramatically reduced.

    It is hard to apply to things like spoke nipples since the rust needs to be in contact with the chemical. I wrap some paper towel bits around the parts and secure with a twist tie or small bit if wire. Then soak the paper towel.
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  10. Chankly Bore

    Chankly Bore Adventurer

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    40% solution of white vinegar and water. Leave for 2 to 3 days. Cheap, and you can use the rest on your fish and chips!
  11. Boomer343

    Boomer343 Been here awhile

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    I use Evaporust in my ultrasonic cleaner as well as in a tray or tank. I now use it to clean carb parts as it dissolves the fuel deposits. As mentioned it isn't fast but if you are restricted to low odour, easily disposed of, non petro chemicals it is great.

    When it starts to get depleted I use it to soak camshafts and followers in. It removes the old burnt on oils and gives a much better opportunity for a proper evaluation.
  12. solidol

    solidol Adventurer

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    Thanks guys, I'll give it a try.

    What supposed to be quick 10 minutes job turned out to be a bit more than that. Swivel socket joint is crucial to get to one of the bolts on the exhaust port. Still ended up removing gas tank to get to vacuum lines (I blocked it off at the Y joint keeping oem pieces off of carb in place). Also wanted to inspect condition and everything since I haven't removed tank prior to this. Will be removing it again just for cleaning though, but that's left for the other day.

    Haven't started it as it's already past midnight.

    Just need to pick up two bolts with nice round heads that match others and plug those two now empty holes where pump bracket attaches to. Overall I like cleaner look and improved operational simplicity. Though it does feel weird to remove what looks like Honda put some thought into.. ;)[​IMG][​IMG][​IMG][​IMG]
  13. Chankly Bore

    Chankly Bore Adventurer

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    I'm a happy little pixie, the Gasper has just arrived from UNZUD. A little corroded, suspect it was in Japan near the seaside for many years; but only 6000-odd kms. I'll probably ride it, then polish it! IMG_0488.JPG
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  14. Spurlock

    Spurlock Long timer

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    Looks like a very nice specimen, congratulations! How about a picture of those bikes in the background?

    -Bill
  15. Chankly Bore

    Chankly Bore Adventurer

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    Sorry Bill, taken at the tester's shop just after it was uncrated. A bit rude to photograph other people's machines but here is a very tidy 1947 Vincent Rapide. Does anyone else make the special flanged socket cap bolts on Hondas? IMG_0490.JPG
  16. Spurlock

    Spurlock Long timer

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    Not that I have ever seen. Maybe someone else here can chime in.

    Only a couple are still available from Honda but most lengths are discontinued. This US company sells a few sizes of the 8mm hex head/6mm thread bolts:
    http://specbolt.com/productseasyrotator.html

    -Bill
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  17. Kiwigber

    Kiwigber Been here awhile

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    Chankly-If bought in Unzud I dare to suggest that corrosion happened in Unzud-You may not know but Honda Japan did a deal with Blue Wing Honda here in NZ (see what I did then) back in 85/6 whereby they bought the entire stock of GB400's and 500's that was left unsold in Japan.I suspect that your bike was one of the several 100 involved in the deal.
  18. Chankly Bore

    Chankly Bore Adventurer

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    Thank you for the information. Mine seems to be an early one, engine no. in the 200's, but it came with fairly recent inspection documents in Japanese. I bought it from Carbon Garage in Auckland who were good to deal with. A mate nearby ran his eye over it for me. I put 60 miles on it yesterday getting it registered and inspected for our Victorian Classic and Historic Vehicle registration. Various documents have the colour as RED,BROWN and PURPLE! If I was the pretentious sort I'd probably say AUBERGINE or BURGUNDY but I've stuck to RED. I have found parts I need at Partzilla (U.S.A.) and MSP (The Netherlands). The site at cmsnl is great, but their postage charges are really silly, which is a great pity.
  19. Kiwigber

    Kiwigber Been here awhile

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    It must have been the last GB500 left in Japan-Yes I recall seeing Carbon Garage advertising this on Trade Me,I don't know if yours is that old,mine is an 86 and engine # is 1001482-Thanks for the info on MSP and enjoy your ride.
  20. Chankly Bore

    Chankly Bore Adventurer

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    Slight error of mine. engine no. is PC16E-1000325, I guess this makes it 1985. That's what I put on the registration documents, anyway. Only fault with the bike is slight cramping of the hips. I will fit clip-ons with a 40mm. lift to alter my geometry slightly, the anti-ageing cream isn't working. Ebay Germany has a good few secondhand XBR parts by the way.One just need to be rigorous in confirming interchangeability.