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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    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
    #81
  2. Kevinforesthill

    Kevinforesthill Been here awhile

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    Please post a top speed test also if you can. I am very curious if it will still reach 65mph+. I have been assuming the complex carb helps provide a better power band and is why the Riva 180cc engine is more compared to a 250cc rather than a 150cc which is closer to its size, but I have been assuming and would like to hear actual experience. Also do you notice belt wear or smell? I have read a couple scooter forums of people changing out the scooter style CV style carb to the common slide style carbs before, but have not heard from anyone who actually did it whether or not it caused noticeable drive belt problems.
    #82
  3. kfsinc

    kfsinc Chaingolian Observer Supporter

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    Update on the Riva 180 carb saga...

    SHE's ALIVE!! FOURTH time pulling the carb and cleaning it, and a few e-mails with Jack at jack's scooters and she starts, runs and scoots! Went right on up to 60 mph before I got scared and backed off -- certainly a way different feel than my R1100GS.

    Needless to say I'm an expert at pulling and re-installing that damn carb.

    A few things to think about:
    • Read the carb stuff from Jack and do it ALL! I failed to clean out the bowl / starting jet and passage, and the main jet -- BOTH were clogged.
    • Make sure you get all those hoses back on were the belong - and that they don't leak.
    • Re-attaching the air box to the carb was a bear and I finally had to fashion a very short rubber adapter, held in place by hose clamps, to get it to work. Here's the prototype - final version is much shorter, but you should get the idea.
    • Anyone want to buy a nice Riva 180?

    upload_2019-6-6_21-53-54.png
    #83
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  4. Kevinforesthill

    Kevinforesthill Been here awhile

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    Glad to hear you got it running.
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  5. Wentwest

    Wentwest How's that work?

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    On the 200 I found the only way to reconnect the air box to the carb was to take off the battery AND the plastic battery box. Once you do that all is revealed. At least on the 200 you can take the carb off without taking the engine out.
    #85
  6. Pestilent

    Pestilent n00b

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    Kevinforesthill - It is still a CV style carb, not the slide style. Just test rode again, hit 65mph, felt close to the top, but I did run out of road. Great off the line and extremely strong throughout the midrange and top end. Did not notice anything abnormal with the drivetrain.

    Wentwest - I can see how that would be relevant and do understand how it would be, on a stock bike. Seeing as how this riva now has an entirely different carb on it with unknown jetting, a frankenstein so to say, and how often a choke is used as a tool to limp a bike home or nurse it back to life, makes it even more surprising that this boat made it into harbor without being sailed there.

    It needs some more odds and ends from sitting 10+ years but I do believe that this carb is the ticket.
    #86
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  7. Kevinforesthill

    Kevinforesthill Been here awhile

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    Your right that is a CV style carb and not a slide style. I see that now that i have taken a better look at it (diaphragm on top, throttle cable opens throttle plate)….......That is a great find!! When I originally got my Riva it had some carb off a who knows what scooter....probably in the 24mm size or smaller because it was WAY too small and had the auto choke wire cut (it ran, but horribly and only up to 35 mph sputtering the whole way). I looked high and low trying to find a cheap CV style carb for it and couldn't so I found a used and very dirty original Riva carb on ebay for around $75.

    To find a CV style carb that is 28mm, cheap and even made for a Yamaha is a true gem of a find. The only thing it seems to be missing is an easy way to extend the choke with a choke cable.....if you come up with something for the choke extension please post as that would make this a much better option for people like me that inherit a Riva with a missing carb or huge carb problems.
    #87
  8. rileyxo85

    rileyxo85 n00b

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    Hey guys. New here. Been reading all the posts. I've been having trouble getting my Riva to start on cold mornings/nights. Sometimes it just cranks and cranks and the battery dies. I have a battery jump pack that I connect sometimes and it starts right up in these cases. My battery is pretty new. Electrolytes are topped off. Any idea why this happens? When I make a quick stop it and come back to it, it starts right up.
    #88
  9. Kevinforesthill

    Kevinforesthill Been here awhile

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    Welcome to the forum Rileyxo85 BCV Bypass & test.jpg ,

    I don't know for sure what your problem is, but I would suggest starting with the BCV bypass (Image attached). The BCV is a big part of the cold start system and that seems to be where you are having trouble. Nice thing is this procedure is easily reversible and pretty easy and cheap to check. The two hoses you need to cut come through a piece of plastic cover on the right side of the engine directly under the intake manifold routed pretty much like the picture shows. The valve will need to be either shut or very slightly open depending on the outside temperature on start up and fully open after a few seconds of running. (here is the shut off valve that I purchased to test mine as a reference, but any shut off valve with 1/4" nipples will work https://www.amazon.com/HIPA-494768-...d=1560526252&s=lawn-garden&sr=1-1-spons&psc=1)

    Other things to look for would be whether your Riva is running rich or lean by the color of the spark plug (Black=Rich, Brown=good, white=lean) which might give you some indication of a different problem that is causing the hard cold starts.

    Lastly, a dirty carburetor seems to be the cause of almost all problems with these Rivas. If the BCV bypass doesn't work I would suggest trying some Sea Foam engine treatment (the one that goes in the gas tank https://www.walmart.com/ip/Sea-Foam-Motor-Treatment/16664932). Since you can start and run your Riva this might do a decent job of cleaning the carb without you having to remove it, which can be a huge PITA. All you would need to do for this is put it in the gas tank and drive it around for a while. It will clean the carb while driving it and also while it is sitting after riding it. You should notice an improvement within a day or so if a dirty carb was the problem.

    Attached Files:

    #89
  10. rileyxo85

    rileyxo85 n00b

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    thanks so much! is the BCV bypass easy to access? i feel pretty comfortable doing it.

    i put a small amount of seafoam twice, and last night i put about 10% volume of seafoam until it started to slightly smoke when i revved it. how much seafoam should i put in to do a cleaning job?

    if the seafoam doesn't work after a couple days i'll try the bypass.

    i might as well change the spark plugs because i don't know when they were changed last.

    thank you for the great reply!
    #90
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  11. Kevinforesthill

    Kevinforesthill Been here awhile

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    It sounds like you put enough sea foam in it to clean it......Yes the BCV bypass is pretty easy to do. The two hose you need should be coming out of two holes in the plastic cover shown in the attached picture . All you have to do is cut them and attach the 1/4" shut off valve on the cut hoses (Carburetor/Intake side hoses, not on the plastic cover side hose)....pretty simple and there should be enough room without having to take anything else off. You could also take the hoses off the carb & intake and attach your own 1/4" hoses so that you do not need to cut the ones attached to the BCV valve, but you would have to remove the fan (if you have one) to get the hose that attaches to the carb.
    [/ATTACH] s-l2000.jpg img_3577.jpg s-l20002.jpg
    #91
  12. Kevinforesthill

    Kevinforesthill Been here awhile

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    So I FINALLY got around to installing the new tires on my Riva and WOW they are really nice tires. The Vee Rubber VRM 351 ($52 each) that I installed (https://www.amazon.com/Vee-Rubber-3-50-10-Tubeless-Winter/dp/B00J4ZCJ7O) are amazing. I have been very surprised on how well they do on dirt & grave since they look to have a street style thread pattern. I have noticed my acceleration go up and they stick to the road great. I little excessive with their 536 lbs load rating and max speed of 112, but i feel they are well worth the extra money that I spent on them. I had put some cheap Kendra K329/K413 ($29 each) scooter tires on the Elite 80 that I had and these are so much better that it is hard to even compare the two.
    #92
  13. Wentwest

    Wentwest How's that work?

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    There's a big difference in ratings between the Kenda and the Vee, Kenda is a 50J and the Vee is a 59S. That's a lot. And the Vee is made for lower temperatures and wet conditions, while the Kenda is made for the opposite. You get what you pay for, which is a good thing. I'd be interested in the wear experience.
    #93
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  14. rileyxo85

    rileyxo85 n00b

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    OK SO...

    I checked the two tubes coming up and out from the BCV and the one going to the carb was already cut and plugged with a bolt on the BCV side:

    [​IMG]

    The other side of the tube going to the carb was just cut open to the air.

    So I disconnected the tube going to the manifold and put my own tube in and connected it to the tube that was cut on the carb with a shut off valve between them exactly like the picture you showed.

    [​IMG]

    The only confusion is that you say it needs to be fully open when it's up and running, however if mine is fully open it dies. It only works when I fully close the valve.

    Is it possible you got the open and closed position mixed up when you replied to my post?
    #94
  15. Kevinforesthill

    Kevinforesthill Been here awhile

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    I was pretty sure that it was closed (or slightly open) on start and open after it warms up but its been over a year since i did this on my scooter, so I may have written it down backwards back then....and I really do not know for sure since I put mine back to stock because the BCV wasn't my starting problem (Bad float level was my problem).

    I am glad to see that you found the problem, because having one side plugged and the other open i am sure was a huge starting problem.
    #95
  16. rileyxo85

    rileyxo85 n00b

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    i'll run it tonight when it gets cold and see what happens.
    #96
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  17. Kevinforesthill

    Kevinforesthill Been here awhile

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    Hey Rileyxo85, any update on your BCV bypass? Did you get it to work for you?
    #97
  18. rileyxo85

    rileyxo85 n00b

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    Yep. It seems like whatever it is it has to be in one position when it's cold to enable the "choke" and the other position while running warm. I've only tried it twice so far in cold-ish weather, but it seems to be doing the trick.

    My only other issue is that the battery is weak if I don't ride it after a couple days. I put a weak solar charger on it to see if it'll help.
    #98
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  19. rileyxo85

    rileyxo85 n00b

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    #99
  20. Wentwest

    Wentwest How's that work?

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    Not that I ever saw. Your experience may be different. If the current battery is old, it might be slowing pooping out.