1981 Honda C70 Passport - I know nothing

Discussion in 'General' started by JAG_C70, Oct 6, 2019.

  1. JAG_C70

    JAG_C70 New Member

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    Hello, happy to join this forum.
    I have had this 81 Passport for a few years, and I had to put it into storage for a year recently. Just got it out and got it running again, got it tagged and road-worthy, more or less. (New battery, some bulbs, cleaned the carb, etc.)
    I just ordered a 15T sprocket to replace the 14T stock sprocket as recommended numerous places online, so I will update when I do this. My question is - do I need to do anything special to the chain? Chain seems to be in fine condition.

    In fact the bike has only 900 original miles on it. But it sat for years and years before I bought it, so there was a lot of replacing anything rubber or plastic. I'm convinced the bike spent years on the side of a house or barn and never moved (in the southwest, with sun blasting one side and not the other) - so all the plastic on the right side was literally disintegrating, while on the left side, totally fine. (Battery compartment cover, shock cover, front fender right side was falling apart, legshield was so cracked the original owner had put aluminium body tape over the cracks...etc.)
    I really want to find a new legshield for the bike, but the ones I've seen are expensive.

    I don't know much about mechanical aspects of motorcycles, so it's been fun to learn some basics on this bike, and I hope to keep it up. i want to find an early 70s Honda CB350 for my next project. But I want to get this thing all sweet first.

    Anyway, happy to be here and it's nice to have somehwere to come ask questions.

    Also - is it just me or is the Speedometer a total liar?
     

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    #1 JAG_C70, Oct 6, 2019
    Last edited: Oct 6, 2019
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  3. Gary

    Gary Well-Known Member

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    That left side picture sure looks great. Some of that plastic and or parts are expensive but if you can get it do so,it might not always be available. It would make a difference if you ever do sell.
     
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  4. racerx

    racerx Administrator
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    Could very well be the actual mileage.

    Couple of things I'd tend to, right now:
    The chain is probably toast. At the very least, take it off the bike, solvent clean it and check for stiff links. How far does the chain bend, perpendicular to its direction of travel? If it forms a convincing "U" shape, under its own weigh or/and you find arthritic links, do yourself a favor and replace it. The bike will run a little better and the sprockets will last a LOT longer. Job #2 learn how to clean the oil spinner, as well as the screen; that, along with timely oil changes, will be the difference between an engine that lasts well beyond 10,000 miles and one that's gasping and generating enough oil smoke to worry about being hauled in for crop dusting without a license...by 2000 miles.

    Might want to lube the cables and replace any that are still binding afterward. Can't imagine the tires and tubes are too healthy after 3 decades, either. That's a good time to check the brakes. new brake shoes are cheap insurance.

    Otherwise, looks like a pretty nice bike.
     
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  5. kirrbby

    kirrbby Well-Known Member

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    Having the bike running and riding is the BEST motivation to spend some time and money on it.
     
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  6. JAG_C70

    JAG_C70 New Member

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    Thanks for everyone's replies! It has new tires and tubes, which I did last year before storage. All the cables are fine, and the brakes are in good shape too. A few years ago not long after I bought it I went through everything with a buddy who knows more than I, just to make it safe to ride.

    I guess I need to invest in a chain tool! Not sure how to get the chain off otherwise. Total noob here. :)

    Ah - one of my questions is: if I'm switching from the stock 14T sprocket to a 15T sprocket, do I need to add a chain link? Or does the same size stock chain work as-is?

    For numerical clarity, I'll be changing the gearing from 14-36 to 15-36. Anyone who's done this to a Passport I'd love to hear from you! Thanks
     
    #5 JAG_C70, Oct 9, 2019
    Last edited: Oct 11, 2019 at 7:42 PM
  7. Gary

    Gary Well-Known Member

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    Sometimes you have to add a link-sometimes you don't. The correct way is to replace rather than extend it. The clip used to hold the link together is the weak point,ideally less is better

    chain link.jpg
    Look for this on your chain,carefully remove that clip thats how it comes apart. Take note how that clip is on- the open end of the clip faces opposite of chain travel
     
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  8. JAG_C70

    JAG_C70 New Member

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    Thanks Gary!
    I got the chain off successfully and counted the rollers and determined I need to buy a chain that has 2-4 more than the stock 96. I ordered a 120 roller in size 420 and a chain breaker to go with it. It comes with a new master link connector - so once that arrives I should be all set to finish my sprocket project. I appreciate your tips!

    My other project has been to get the throttle working more smoothly. I've done all the adjusting I can, and I replaced the throttle grip which was a little deformed inside the housing and causing it to stick even more. It's on the road to recovery - I got some spray lube and was going to do the plastic bag trick for lubing the cable, but then I saw on youtube that someone went and invented a little gizmo that you can attach to the end of the cable housing and shoot lube into the gizmo which forces it down through the whole cable housing with pressure. Pretty cool. I can't help but take any chance to buy a new gadget. I should have the C70 all stitched back up by Monday night, if the new stuff arrives Monday like it's supposed to.

    Thanks again


     
  9. Gary

    Gary Well-Known Member

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    Good to hear. I'm not at all familiar with how your throttle works but on a mini they don't snap back to idle like a big bike just so you know. If it's got a throttle that the cable is run through the handle bar you want to use a minimal amount of white Lubriplate type one the "pipe" and "hinge" mechanism- something oily and not sticky
     
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  10. racerx

    racerx Administrator
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    Contrary to popular belief, master links aren't a serious weakness. If they were, the carnage would have led to a solution...such as used on race bikes, no master link. Eliminating the master link is possible but not very practical; the work required to R&R a chain would be silly. Honda used to run chains with 2 master links on the CT90, those fitted with dual wheel sprockets, until they debuted the dual range sub-trans. In my experience, the main disadvantage of running a master link on one of these bikes is that they tend to dry-out faster than the rest of the chain, resulting in a stiff spot...and chain shake at high speed...if not maintained adequately. For the general public, the biggest issue is doubling the chance that someone will install the clip incorrectly, resulting in its being peeled-off the chain, with nasty results.

    Bottom line, if you know what you're doing, 2 master links can be used...but...I don't recommend doing this, either.
     
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  11. JAG_C70

    JAG_C70 New Member

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    Thanks racerx, you are a font of bike wisdom. In fact I have new chain in hand and ready to get it on the bike with new sprocket. The old chain, as it happens, was almost good as new once cleaned and lubed, no noticeable stretch/looseness - just not quite long enough. It's a good learning experience for me for sure. I will throw the old chain back on with the old sprocket in case I don't like the new gearing.


     

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