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Yamaha Riva 180 Repair & maintenance information

Discussion in 'Battle Scooters' started by Kevinforesthill, Oct 15, 2018.

  1. Kevinforesthill

    Kevinforesthill Been here awhile

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    That is a good point. I don't know about anyone else but I did install a paper fuel filter on mine to keep that gas tank crude out of the carb. I do not think the Riva's originally came with a fuel filter, but it is well worth the few bucks it costs.
    #61
    minimac and Wentwest like this.
  2. Kevinforesthill

    Kevinforesthill Been here awhile

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    #62
  3. Kevinforesthill

    Kevinforesthill Been here awhile

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  4. Wentwest

    Wentwest How's that work?

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    The one in Petaluma looks like a good prospect, but I try really hard to stay away from Yamahas. They are just too complicated and fussy. Sometimes I fall for one and get involved, but I always end up cursing the carburetors.
    #64
  5. kfsinc

    kfsinc Chaingolian Observer Supporter

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    I'm the proud new 'owner' of a 1984 Riva 180. Picked up by a friend at a garage sale. 13K miles.

    The side covers and seat were off, but with the bike. Near as I can tell the bike hasn't been ridden in 10 years or so. Everything looks to be in great condition, but the carb...It's was stuck/froze. Fortunately the bike came with what appeared to be a very clean extra carb. That's been disassembled and cleaned in an ultrasonic cleaner. The diaphragm looks good and seems to work fine. Floats are good as are all gaskets. I removed the old carb and am in the process of installing the 'new' one.

    The hoses are a real PIA!! I have several diagrams and a few pictures so should be able to get it re-piped. An helpful tips? Jack's suggest removing the engine/drivetrain for carb work -- I may take that route.

    It does turn over, and seems to make the right noises. Oil looks good and tank is empty with no visible issues. Tires are on order. Any other suggestions before we put it back together and light the fire? Pictures coming soon.

    Great info on this thread and thanks to everyone going ahead of me on this journey!
    #65
  6. fullmetalscooter

    fullmetalscooter Let me take this duck off

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    Pray to the carb gods that there no issues with the pain in the ass bystarter on riva. Good luck. At least now everyone knows you can get after market rollers that will fit and work.
    #66
  7. Wentwest

    Wentwest How's that work?

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    Jack is right about taking the engine out. It's a two person job in my experience, because it's sort of clumsy lifting the frame off the engine. Then it's very easy to work on the whole engine and carb and see what you are doing. Only issue to me is that I could not test things well before putting it all together again. USE NEW GASKETS.
    #67
  8. dot_dash

    dot_dash Adventurer

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    Welcome kfsinc and congrats! I hope you get it on the road soon. Please post pics!

    Regarding status of my restoration: Still haven't ordered the battery or hoses. I got a Metropolitan I've been playing around with as well as fixing a friend's Ruckus. Since my Riva is completely apart in the back corner of shed, it's given me little incentive to go out there hehe. I will soon though.

    @Scooter dude -- The clutch sounds similar to a Ruckus clutch. A snap ring holds the clutch compression together and it lives in a slot on splines. There are some interesting ways people get these off but what has worked best for me is to apply soft + even pressure to the drive plate, compress the clutch as much as it will go down safely, and then use a tiny flat head or something to slide the snap ring out from it's housing. Without compressing the clutch, the ring has no room to leave it's home. Hopefully this will be of some help to you if you haven't already figured it out.
    #68
  9. kfsinc

    kfsinc Chaingolian Observer Supporter

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    so... got the carb back on and the hoses connected -- Something's not right as it's spewing fuel from the vent for the main air tube port on the carb #1 in this picture -- this is supposed to be open to the air, so I'm pretty sure it shouldn't be pissing fuel. All indications are that the float valve may be stuck open :-( -- back to square one.

    Really thinking I'm going to remove the engine / drive train this time per Jack's suggestion.

    Scooter Carb Picture.png

    BTW -- whomever designed this fuel system should be locked up ;-(
    #69
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  10. Wentwest

    Wentwest How's that work?

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    I agree about locking up the engineers. It's overflowing, and it might be getting into the oil, too. When you finally think it's fixed, change the oil. Meanwhile, it's clearly either the float not floating correctly or the float valve is dirty or worn. When you have it all apart you can clean the seat of that valve by cutting one end off a Qtip, chucking the longer portion into a power drill, dip the soft end into something like Brasso or metal polish, insert into the seat area, run the drill and polish the seat. Rinse well with solvent. It'll shine like new in there.
    #70
  11. Pestilent

    Pestilent n00b

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    I have been digging, does anyone know of a solid replacement, verified to fit with or without modification, that does away with all that vacuum, fuel line, and carb nipple tom foolery? Looking at a yamaha tw200 carb or a generic gy6 carb to replace mine as I refuse to repair or clean it.
    #71
  12. fullmetalscooter

    fullmetalscooter Let me take this duck off

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    After 10 plus years of read forums I ve never seen anything but $#()_*& )#(UFJKL:DKFJ when it comes to the carbs . Here the like to google search so it shows only forums and I ll let you wade through the post to see what they say . https://www.google.com/search?q=forum+riva+180++carb+replacement&ie=utf-8&oe=utf-8
    You best bet is to get a yahoo email acount and sign up to the yahoo RivaRiders group on Yahoo groups . Beyond that you could also go to fuel injection using this 300 bucks kit . https://www.ecotrons.com/small_engine_fuel_injection_kit/ read more here. http://scootdawg.proboards.com/thread/37715
    #72
  13. Wentwest

    Wentwest How's that work?

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    The Riva 200 carb is certainly better. I don't know if it will fit. On the 200 I worked with, the carb was overflowing and I replaced everything in the bowl, no luck at all. What did fix it was to set the float level at 29mm instead of the 26 in the repair manual. It was just a last ditch effort, after I had been through the carb many times. At about 31mm the valve closed when I screwed on the bowl, so I knew it was touching bottom.
    #73
  14. Pestilent

    Pestilent n00b

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    Im going to buy the yamaha tw200 carb and give it a go. Will update with results
    #74
  15. kfsinc

    kfsinc Chaingolian Observer Supporter

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    Update: removed the carb and re-adjusted the floats, tested as much as possible for accurate height by using a bottle to pour some gas into the gas line nipple -- seemed to work - and Jack's Scooter tutorial (THANKS) I then spent a lot of time clearing out the jet from the bowl to the starting circuit. Put it back on and she started right up!! Actually ran pretty good for about 30 secs, then wouldn't go off idle -- ANY throttle movement would choke it out. But she started - -every time. After a short rest, same thing -- good start, good throttle response - even to WOT, but then back to idle only. Thinking that the thermal couple on the bottom of the cab is triggering something in the MA solenoid. Or that the airbox vacuum hoses aren't connected to the Airbox and that's messing up the fuel/air mix.

    I've now spent countless hours trying to get the airbox re-conneted to the carb.. IMPOSSIBLE to get the rubber pipe from the box to the carb to connect to the carb. Tried it on the old carb on the bench -- same problem. just doesn't mate up correctly. I'm thinking that the rubber has shrunk a little from age? Or, possibly from my using a head gun to soften it up a bit during the re-install fight.

    I'm going to buy a replacement for that pipe -- hopefully they're available.

    The 'free' scooter is turning g to to be a big time sink.... It WILL be for sale when I get it running reliably. ;-)
    #75
  16. kfsinc

    kfsinc Chaingolian Observer Supporter

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    VERY interested to hear how that works out. I see zero value in this highly complex carb system...
    #76
  17. Wentwest

    Wentwest How's that work?

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    I think your float level is now too high, so it runs off the cold start system but can't draw fuel through the main jet.

    The intake tubing is frustrating too. Would soaking it in boiling water help?

    I prefer Hondas. Yamaha seems to come up with these screwy engineering solutions.
    #77
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  18. Pestilent

    Pestilent n00b

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    Update: the $25 tw200 carb arrived today. It was a 50/50 mix of a rig and an install as the throttle cable is now on the other side of the carb and the manual choke still needs to be figured out, but, out of the box it fired right up without any choke, ran smoothly at idle, and like a raped ape throughout the powerband. Fine tuning will begin tomorrow along with pictures.
    #78
    Kevinforesthill likes this.
  19. Wentwest

    Wentwest How's that work?

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    My experience is that my scooters start at 40 to 45 degrees without a choke, but they do need to run a few minutes before they stop hesitating on acceleration.
    #79
  20. Kevinforesthill

    Kevinforesthill Been here awhile

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    Hey Joe Dirt/Scooter Dude, I wanted to ask how you like the Dr Pully 6g Sliders. I bought some but haven't put them in the scooter yet (Been fixing a Honda CT110). I took Yamaha scooter out on a ride yesterday and it rode fine but hesitated on acceleration and I think it is because my variator is gummed up with the grease I used.....finding a good grease is hard to find. Just wondering your experience with the 6g sliders
    #80