Yamaha Riva 180 Repair & maintenance information

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

  1. FreddyBiz

    FreddyBiz n00b

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    Hey Kevin,

    Thanks for the reply and putting the carb diagram house sizes together and confirming!!! I ordered some vacuum lines and got the engine removed and carb off. My problem now is I want to take the carb apart to thoroughly clean but no shop online seems to have the float bowl gasket anymore. What are y'all doing for the gasket?!
  2. Kevinforesthill

    Kevinforesthill Adventurer

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    Hey FreddyBiz,

    I just re-used the gasket.

    Looks like you need Yamaha part number 25G-14984-01-00

    ----------------------------

    Here is one that I found on ebay. But yeah, it doesn't look like there are many out there, in fact this is the only one I found.


    $20 + $5 shipping
    https://www.ebay.com/itm/Yamaha-OEM...535377&hash=item3fc87cc0c6:g:ZV0AAOSwKvZdPNe8

    --------------------------------------------------
    Partzilla parts diagram (For Yamaha part number reference)
    https://www.partzilla.com/catalog/yamaha/scooter/1984/riva-180z-xc180zl/carburetor
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  3. JerryH

    JerryH To Each Their Own Supporter

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    I just read this thread. I think it is important to keep these old scooters on the road. If you had the parts, you could keep them going pretty much forever.
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  4. Kevinforesthill

    Kevinforesthill Adventurer

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    That is why I started writing all of this. When I first got my Riva 180, I quickly realized that I was missing a lot of the original parts and the scoot ran like crap. Then when I went looking for parts and repair forums I found pretty much nothing useful (well, other than Jacksscootershop.com). So I figured if I was going to go about doing research to keep my Riva on the road, I might as well share that information to help others keep their Riva's on the road also . Some of the things like the rollers and drive belt are maintenance items and need to be replaced periodically, but as far as the internet was concerned the rollers were special made and there was no replacement belt, so if you owned a Riva 180 you were pretty much screwed. If nothing else, the roller information and Gate replacement belt number is great information that should help people keep their Riva's going. I could probably get into more detail with the Riva, but I have moved onto more projects (just finished a 1974 Honda XR75 for my daughters 10th birthday) and well, my Riva runs fantastic so I don't really have a reason to keep tearing into it.
  5. JerryH

    JerryH To Each Their Own Supporter

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    I appreciate what you have done. I have spent my whole life as an auto mechanic, and I believe in repairing not replacing. I have a 57 year old car that runs like new. There is little reason why there couldn't be hundreds of thousands of old cars and bikes out there on the road instead of being scrapped and replaced with the new computerized junk they make now that nobody can work on.
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  6. Kevinforesthill

    Kevinforesthill Adventurer

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    I definitely agree with you.
  7. FreddyBiz

    FreddyBiz n00b

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    Thanks Kev, you rock!

    I totally agree as well JerryH, repair and ride forever!!!!
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  8. FreddyBiz

    FreddyBiz n00b

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    OK, good news and bad.

    Good - Got the carb apart and the starter jet was clogged, a little guitar string and carb cleaner and its spraying through now! The gasket on the float bowl was fine, so I was able to reuse it. Really appreciate the links in case I needed to buy that one!

    Bad - I found that the thermo switch on the bottom of the carb with electrical wires, has one broken wire! I have only been able to find 1 replacement online and they want $120... ugh. Riva might be dead on that price tag. Any suggestions? I am currently trying to tinker with it and see if I can solder the wire back on....
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  9. Kevinforesthill

    Kevinforesthill Adventurer

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    I am pretty sure that thermo-switch is for the fan (Green sensor with black & green wires IIRC). Don't remove the sensor as I am pretty sure there is heat transfer liquid between the sensor and the bottom of the carb, and that stuff is not cheap ($43 for 150ML is the cheapest I saw). I know this because I removed mine trying to get the fan to work properly, but I ended up connecting the fan to a accessory power wire and added a toggle switch (after I tried using a generic thermos switch that didn't work out very well because it was too big......cost me roughly $20 online). It gets in the 100's where I live so I wanted to make sure the fan worked on mine, if it doesn't get very hot where you live you would probably be fine without it.



    Excerpt from Jacksscootershop.com (http://www.jacksscootershop.com/yamaha_info.html):

    "The Riva 180 uses an electric fan in the engine area to cool the carb (probably to help prevent vapor lock). There is a thermo switch attached to the bottom of the carb, which is supposed to control whether the fan is on or not. On most 180’s this switch seems to have worn out. The fan stays on all the time, even with the ignition off. This will wear out your battery in a short amount of time.

    You have at least three choices:

    1) Do away with the fan entirely. Assuming you don't ride you scooter on many 100 degree days in stop-and-go traffic, I would think that you'd be ok. I have never had a carb problem with the fan removed.

    2) Get the specs of the thermo switch [the thermoswitch is closed (infinite resistance) up to a temperature of 54 degrees Celsius (129 degrees Fahrenheit). It opens up (zero resistance) at higher temperatures.] and source a replacement part at your local electronics shop.

    3) Wire a switch in-line with the fan, and just turn off the switch when you stop your scooter."
  10. Geshka

    Geshka n00b

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    Hello fellas. Glad I found concurrent thread about Riva XC180. Allow me to introduce myself - I live in Canada, in national capital region . Like to restore things - reviving old tube radios, restored few metalworking machines and equipped my ever messy workshop. We bough a cottage a month ago and to my greatest surprise I found Yamaha Riva XC180 in storage shed under piles of dirt and junk. It is almost complete but hugely neglected. I am hoping to restore it to road-worthy condition and also make it looks good (most challenging part for me ,LOL ) . So far I am carefully stripping it down, washing and inspecting.
    To be continued ....
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  11. Kevinforesthill

    Kevinforesthill Adventurer

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    Welcome aboard Geshka
  12. SimonLeBon

    SimonLeBon n00b

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    Hi guys,

    I just bought a Yamaha 180 from Craigslist to tinker around with. I bought a new battery and tried to start it. Surprisingly it started and idled but when I touched the throttle it died instantly. I thought the jets were dirty so I took the carburetor off to clean it. I noticed the pilot screw was stuck and I was unable to unscrew it. The previous owners tore up the head of the screw to I tried to use a screw extractor but this broke off and is not coming out so I think I have to look for a new carburetor.
    I read on here someone used a TW200 carburetor for their Yamaha Riva 180 and it was working fine. I'm thinking of doing the same but I'm not sure how to connect all of the hoses. Can I by pass some of these solenoids or BCV?

    Thank you,
  13. Kevinforesthill

    Kevinforesthill Adventurer

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    That is my understanding. You would need a carb that has a choke (or auto choke) and disconnect or cap off the BCV and solenoids since they are basically a complicated old style auto choke.
  14. SimonLeBon

    SimonLeBon n00b

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    Thanks Kevinforesthill!

    When I bought the Riva the owner gave me another carburetor that he had laying in his garage. It was pretty old and rusty but yesterday I decided to give it a shot and cleaned it. I was able to connect all the hoses the right way and gave it a try. Boom the Riva started with opening the throttle a little. As soon as I let it idle it died. Now I need to turn up the idle RPM so it won't die on me.
  15. Wentwest

    Wentwest How's that work?

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    You have to be really thorough with the carb cleaning, and the gaskets, because there's really no way to test your work without going through the whole process of reinstalling the engine in the frame. That's what turned me to other scooters. When the 180 is running right it's a lot of fun, fast, responsive and light. And Jack does have a supply of used parts and a lot of knowledge, too. You can email him directly. I live sort of near him and went there to scout the situation, and came home with lots of stuff I needed to finish a project I was doing on a 200.
  16. Kevinforesthill

    Kevinforesthill Adventurer

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    Isn't Jack in Galt, CA? I thought I had seen that somewhere. I work in Sacramento, so its not far to get to Galt and I have been curious on what his collection looks like
  17. Kevinforesthill

    Kevinforesthill Adventurer

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    I agree, try to up the idle screw and if that doesn't fix your problem then the idle jet is probably clogged (my best guess). These carbs can be a PITA to get completely cleaned.
  18. Wentwest

    Wentwest How's that work?

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    I met Jack in San Jose, where his yard full of parts was.
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  19. Kevinforesthill

    Kevinforesthill Adventurer

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    Lol.....yeah, I don't want to drive to San Jose, the traffic from here to there is a nightmare. Thanks for the reply wentwest
  20. SimonLeBon

    SimonLeBon n00b

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    So my Riva seems to be starting without any difficulties. And does not stall anymore when it's idling since I increased the idle RPM. The thing I noticed today when I was riding around the block was that my petcock is leaking fuel. I read that this is a common problem. When I opened the petcock I noticed the 2 rubber membranes are worn out. I'm planning on changing the vacuum petcock to a manual petcock. If I'm correct I need to order a manual petcock with 46mm bolt spacing. Any idea's where to get one cheap? The one I found is $46.