Honda GB500 thread

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

  1. RiskyR

    RiskyR n00b

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    Do you feel much difference between the standard 500cc version and the XR600 cylinder?
  2. XRLated

    XRLated Long timer Supporter

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  3. Spurlock

    Spurlock Long timer

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  4. Claytonroy

    Claytonroy Been here awhile Supporter

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    I was following that BAT auction as well. Some really odd bidding behavior...and even trash talking at the end. “ Winner” went from a $9100 bid ..then to counter $9500, upped all the way to $16K. :drink?

    Wondering if he’ll follow through with payment.
  5. XRLated

    XRLated Long timer Supporter

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    Excellent point about actually paying. Hadn't considered that.

    I'll have to go back and read the comments if they are still available.
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  6. XRLated

    XRLated Long timer Supporter

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    I'm interested in the group's collective experience and advice: stop me before I buy again!

    Or maybe this is more an invitation to play along by on a thought experiment, both demonstrating your knowledge and also helping school me?

    A puzzle I can't quite solve myself, but I'd love to get figured out, whether anyone (me or someone else in the group) ever acts on to my/your/their profit or chagrin:

    I keep looking again and again (with my finger hovering over the "bid" button) at this $350 GB gas tank that I recently posted here about and that is now relisted once again on ebay:

    https://www.ebay.com/itm/Honda-GB500TT-gas-tank/143778968333?hash=item2179e4f30d:g:7hkAAOSwVRBfdeh5&LH_ItemCondition=4|10

    Is this tank a steal at $350? Or a decent deal? Or a fool's crusade?

    The decals all seem intact, and all but a small part of the painted surface seems in great shape: buff, polish, done! So, could a talented body-worker coax out the dents, and could a talented painter patch the small area of chipped paint, bringing this tank back to showroom "as new" for a reasonable price?

    Or is the damage not so easily and cheaply undone? Are the dents not so easily massaged back to original shape, instead requiring more extensive metalwork and/or patching compound, followed by a completely new paint job and new decals? Is the condition of the paint or clear coat such that buff and polish alone might not cut it?

    The tank with shipping is about $440. If the minimal expert repairs could indeed turn the trick, how much might that expert dent-repair and touch-up paint cost? I'm thinking $200 or $300 or so total for everything? Or am I off base?

    If, say, $300 would cover the minimalist repair, then the total cost to buy, ship and fix the tank would be under $750. Would the resulting tank likely sell for more than that? An NOS tank recently sold on ebay for $1500. Would this fully restored tank likely command $1000, $1100, $1200, more? Or only, say $600 or so? Would all the added-up costs of the tank purchase, shipping, and minimalist expert repair end up higher than the worth of the resulting "as-new" tank?

    I understand there is guesswork and unknowns that preclude a definitive answer, but--for anyone interested in playing along on this thought experiment--what do you all think?

    I myself feel as if the tank is a steal on ebay at $350, BUT--

    ...no one is buying it. So, are folks failing to see the potential value? Or am I underestimating the cost/difficulty to restore the tank? Or overestimating he value of a restored GB tank? Or both? Or what?

    No obligation to reply, but very interested in the thoughts of whoever does have something to add--thanks!
  7. Chankly Bore

    Chankly Bore Been here awhile Supporter

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    Some sort of suspicious logic tells me that the vendor has already considered these possibilities. Therefore ask him/her what he paid for the "expensive N.O.S. tank" and be prepared to spend at least that much. I had a tank done here in Australia and my wallet is still pining for the next feed.
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  8. Spurlock

    Spurlock Long timer

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    Lots of good questions there. First off the starting bid is $350 but we don't know if there is a reserve higher than that. Secondly the photos of the dents are not at all helpful so it's hard to know whether the dents are fixable without filler and complete repainting. The drop down filler neck inside the tank really limits access for typical paintless dent removal probing from the inside, so options might be limited to hot melt glue stick pullers on the outside or weld-on puller rods followed by filler and total repainting. For comparison I had a badly dented tank (single dent but a bog one) professionally repaired and repainted with original paint and repro decals. Cost was around $900 and eh result was not quite back to original. Bottom line: I would ask the seller for better photos of the dents before bidding.

    -Bill
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  9. ItalJap

    ItalJap Adventurer

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    @XRLated gas tank:
    First off, many of your posts seem, in my eye, to pose you as a genuine GB enthousiast, happy to know you're not the only one. Way to go!

    Living on a budget most of my life, I think I understand your doubts as a mental process.
    While I learned early on that some goals were just out of reach, financially, so didn't need attention, your doubt seems more about "is it sensible", a likewise pre-decision.
    Well, you answered more or less yourself, by calculating a possible profit when selling. So, next question, are you a trader seeing a possible profit or a collector, who cannot bear to see a respectable gas tank to be junked, eventually?
    As a trader, you should inquire as Bill advised and keep CB's experience in mind, but it's your trader's ego that will decide, depending upon how you feel about GB's future: divine like Vincents or bleak like Horex Imperators.

    You might have 5 or more reasons for buying if you're biased to be a "collector" and willing to spend some money without being sure of "no regrets":
    • It will improve my karma more than burning my money or upgrade the garden
    • I might need it in case one of my tanks gets damaged, although that's unlikely
    • I consider this an item entitled to respect, not just as a dumb replacement or a clever investment
    • I secretly want to restore another GB and a fine gas tank is probably of the essence
    • I want to find out if there's craftsmanship around for a restoration I would call accomplished
    So, in my opinion, the answer is all within your own mind, as long as it bothers at all below $1000,-.
    Otherwise, have a drink, ask the wife, toss a coin and enjoy the ride.
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  10. XRLated

    XRLated Long timer Supporter

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    Thanks for replying back everyone--great advice regarding the $350 GB500 gas tank!

    As expected, I learned a thing or two--permanent wealth that continually appreciates.

    If in two weeks I was not moving into a new house, setting up a new shop, and landscaping a new yard while the Pacific Northwest rains start rolling in here in earnest, and if I did not already have about enough parts knocking around now (including two decent gas tanks) to put together two mostly finished GBs, and if I also did not have an XL600R needing a full restoration once I have the time, well, $350 might not be a bad investment to see what might be done with that tank, but, thanks to the shared wisdom, I'm understanding now that this tank may not be the "don't pass-up!" screaming deal that it first seemed to me, and so I'm keeping my cash in my pocket on this one, close-by and at the ready to throw at the new house/shop/yard/etc....

    Buying a $350 project tank may be something to do once I run out of other stuff to do in 2022, 2023, 2024;... then again, I already recently acquired "can't pass-up!" screaming deals on a couple VE40s and a couple VE10s, all muck-and-mire-infused to some degree or another, one a fire survivor, to play with when I run out of house/shop/yard/GB-assembling/XLR-restoring stuff to do.

    Thanks group for one less thing on the to-do list!
  11. wiguzziman

    wiguzziman Been here awhile

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    Anyone out there know if there's a simpler fix to the problem of a worn small end on the connecting rod in a lot of Japanese motors other than replacing the connecting rod; which I'm pretty sure requires pressing the carnk apart? Seems like the Japanese manufacturers chose not to put a replaceable wrist pin bushing in the small end of their rods (probably a cost cutting measure) and they do wear out due to neglect (not changing the oil regularly, or abuse or both). ????
    wiguzziman
  12. Spurlock

    Spurlock Long timer

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    I had one GB engine with a worn out con rod small end and had a motorcycle machinist press it apart and install a new Pro-X rod kit. It was not a terribly expensive job, but has to be done by an expert to get alignment right during reassembly. I had asked him about the possibility of machining the rod for a bushing but he said that would also require pressing apart to get the rod out, so might as well just install a new rod kit and end up with complete new top and bottom ends. He pointed out that the underside of the piston and wrist pin area are exposed to extreme heat which degrades oil, and since the pin and rod are the same basic material, galling can occur if oil is dirty or the engine overheats. He said the best solution is to use a DLC coated wrist pin (DLC=Diamond Like Coating). Here's an interesting article on the process:
    https://blog.trendperform.com/explained-wrist-pin-finishes

    -Bill
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  13. Spurlock

    Spurlock Long timer

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  14. wiguzziman

    wiguzziman Been here awhile

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    Thanks for the reply Bill. I was hoping for some "new fangled" super easy fix, but apparently technology hasn't caught up to this issue yet. Did some checking and presently a new rod kit and the pressing apart, installing, re assembling and truing the crank hits the $300.00 area pretty hard. Guess I'll have to bite the bullet and spend some money. Thanks again!! wiguzziman
  15. Spurlock

    Spurlock Long timer

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    What is the wrist pin to rod clearance on yours? Mine measured 0.004" and made a serious knock!

    -Bill
  16. wiguzziman

    wiguzziman Been here awhile

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    I'm ashamed to say that I don't know what the clearance is/was. I never checked it (dumb mistake), but it "felt" good when I was assemblying it. Sure would be nice to just replace a wrist pin bushing rather than doing the whole new rod kit thing, but apparently such is not the case. :-( wiguzziman
  17. Spurlock

    Spurlock Long timer

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    Whenever the crank is pulled for any reason the main bearings also really need to be replaced. At least the left one, since it is a press fit in the case as well as onto the crank, and pressing the crank out of the crankcase risks damaging the bearing. And the bearings have to be OEM and not generic, due to the lack of adequate chamfer on generics.

    -Bill
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  18. wiguzziman

    wiguzziman Been here awhile

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    Thanks for the info Bill. My question about the small end rod bushing (or lack of) wasn't GB500 specific. It was kind of four stroke singles in general related. In fact the bike with the rod issue is a Honda FT500 Ascot 500cc single. I also posted the same question on the ADV's FT500 Ascot thread. Got pretty much the same information from that site as well. Just trying to learn a few things, and I really appreciate the response! wiguzziman
  19. XRLated

    XRLated Long timer Supporter

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    What clutch parts do folks recommend being replaced with new when performing a complete clutch rebuild on an unknown quantity GB engine?

    I am preparing to address the engine that I recently purchased cheap on ebay, which the seller never ran but was told ran fine by the original seller. The story is that the engine had 4k miles when it was pulled out of a crashed bike. I have no idea what treatment or storage the engine received since the crash or how long it sat.

    Also: any diagnostic and preparatory advice before putting the engine in the frame and trying to start it?

    I still have at least a month minium before my shop is ready for working on bikes again, but want to be well educated with a rehab plan by the time I'm finally relocated and able to remove the engine out of the seller's shipping container. So far, I've peeked at the engine in the container and seen the dozen 360°-view pictures that the seller posted on ebay--no glaring issues visible whatsoever: looks clean and wholly unblemished! Other than that limited visual, I'm in the dark though.

    The reason I'm asking about the clutch in particular is because the clutch was not included with the engine, so I've bought a used clutch on Jauce and need to rebuild it anyway, so might as well do the optimal job with new parts where advisable, but I can also use any other advice as regards the engine as a whole, as it is a black box (though a quite pretty looking one from what I see superficially peeking under the shipping-container lid and looking at the ebay pictures).

    Barring other sage advice, my current thought is to do as much diagnosis as possible with the engine in one piece, then--if the engine passes the diagnostics with flying colors--do whatever rehab and prep I can with minimal disassembly, then see if she starts and how she runs. Only if she isn't a strong runner, will I do a rebuild.

    So, help, please with clutch rebuild advice and general diagnostics and prep advice for a (pretty looking) black-box engine.

    Thanks for any advice!
  20. Spurlock

    Spurlock Long timer

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    I would look at the clutch outer for signs of excess wear on the aluminum "fingers" where the tabs of the friction discs engage. If they have significant grooves I'd try to find another clutch outer. Then check the steel plates for wear and flatness. In my experience they are normally fine, it's rare to see them worn or showing signs of heat damage. I would always replace the friction discs since they have a definite fixed life span after which they start to slip even if they measure the correct thickness. And check the small ball bearing in the pressure plate. If things look good I would not bother replacing the springs.

    When putting the right crankcase cover back on be sure the "holder" part #14 and O-ring #21 are in place. Those parts seal an oil passage between crankcase cover and oil pump and can easily fall out when the cover is removed.
    [​IMG]

    Things to check and prep before installing the engine:
    • Pull the tappet covers and squirt oil onto the cam and onto each valve stem, then check/adjust valve clearance.
    • Before reinstalling the clutch cover, add oil to the pump passage mentioned above while rotating the engine a turn or two. This will ensure the pump is purged of air ahead of startup time. Also use a pump oiler to add oil into the end of the crankshaft, that will lubricate the con rod big end. Also check the oil pump pickup screen.
    • After installing the clutch cover, install a new oil filter and with the engine on its side, add some oil to the filter housing.
    • Spray a bit of fogging oil into the spark plug hole.
    • Rotate the crank until the valves are open and reach into the intake and exhaust ports and squirt a drop of oil onto each valve stem.
    • Remembering Alan's experience with a used oil tank and clogged in-tank pickup screen, be sure to open up your tank and check the screen!
    • Once the engine is in the bike and sitting vertically, once again add oil through the tappet covers so the cam lobes will dip into it. Then before starting the engine loosen the oil line banjo fitting on the cylinder head and crank with the electric starter to confirm oil flow (kill switch off).
    • Lastly, turn kill switch on, start engine, open a beer and stand back and admire.

    I'm sure others will offer some good tips as well.

    -Bill
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