Yamaha Riva 180 Repair & maintenance information

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

  1. Juvenile Senior

    Juvenile Senior Been here awhile

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    If I don't manage to ride it more than the 600 km I did this summer, I am not going to need parts for the next... ehm... 20 years???
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  2. Kevinforesthill

    Kevinforesthill Been here awhile

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    Yeah, the hoses and tires will probably rot out before you need to change anything. Especially if you store your scooter indoors. Granted, you will probably drive it off a cliff if you have to clean the carb everytime you take it out for a ride. If you didn't already know, the carbs on these have a tendency to get clogged and you need to pull the motor out to remove the carb (actually you can remove the carb without pulling the motor, but it is a huge PITA and its easier to pull the motor).
  3. Juvenile Senior

    Juvenile Senior Been here awhile

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    What!? should I store it outdoors?
  4. Kevinforesthill

    Kevinforesthill Been here awhile

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    Sorry, I think the way i wrote it was confusing....but no, you should definitely store it inside.
  5. Juvenile Senior

    Juvenile Senior Been here awhile

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    There is nothing special about these carburetors, that makes them get clogged more than any other carburetor. This model features a (too) sofisticated cold start system with a lot of vacuum lines, electric valves, sensor and controler, all creating too many sources of failure. But the main reason why carburetors clog is, that vehicles are beeing left and forgotten in barns and garages before being eventually sold. And that is not unique to this model particularly. I don't remember ever reading about a scooter or a bike that got clogged while being regularly used (which is of course not impossible if fuel tank and lines are eroding). This is a desease of the rich world, where people buy stuff to clogg their garages with. In the mediteranian region or in Asia, scooters and bikes die of totaly different syndromes... You may call it "Fatigue"...

    I do hope however, that I manage not to need to separate the frame from the engine, mainly since I don't have anyone to help me in my garage.
  6. Kevinforesthill

    Kevinforesthill Been here awhile

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    You can separate the motor from the frame by yourself. I have never had anyone to help me and have done it many times.

    "There is nothing special about these carburetors, that makes them get clogged more than any other carburetor."
    Sorry, but I think you are very wrong in this statement and it makes me assume that you have not removed your carburetor and taken a good look at it. It is a complex carburetor with many small passageways that easily get clogged (a common consensus you will find on all sites that talk about the Riva/Cygnus). Yes in many cases the carb got clogged because it sat for a long time with old fuel, that is a common of almost all clogged carburetors, but this carburetor is especially difficult in getting all of the passageways clean and if you do not it will not start or run properly. While I am by no means a professional motorcycle mechanic, I do work on a lot of small engines and this is the most internally complicated carburetor I have seen.....it is not a standard CV style carb even though it may appear to be one at a simple glance.
  7. Juvenile Senior

    Juvenile Senior Been here awhile

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    Consensus? What is that...?
  8. Kevinforesthill

    Kevinforesthill Been here awhile

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    Consensus = general agreement
  9. Juvenile Senior

    Juvenile Senior Been here awhile

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    Dear Kevin, I knew that.
    Please do show some sence of humor. Otherwise I might suspect you for being a german.
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  10. Kevinforesthill

    Kevinforesthill Been here awhile

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    Lol....German is one of the things I am not, But I do like JoergSprave's YouTube channel if that counts. And sorry, online humor isn't always easy for me to get.....you need to put an emoji or something at the end of it otherwise I am lost :confused :imaposer:rofl
  11. Kevinforesthill

    Kevinforesthill Been here awhile

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  12. Juvenile Senior

    Juvenile Senior Been here awhile

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    So I can join the Consensus, that the Riva carburetor is more complicated than others. And it is a fact that it is difficult to get it out for cleaning. So if you get it clogged, you are going to be miserable long and deep.
    But my point is that it is in your hands to prevent it from clogging in the first place. All the scooters that you see being clogged have one thing in common. They have been standing unused for long periods. So either use what you have, and have fun at it, or live with the consequences.
  13. Wentwest

    Wentwest How's that work?

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    I have to disagree a bit. The Riva carburetor is complex for no good reason, and I have had one clog up in a matter of weeks. After you go through yours and clean it you will understand what we are saying. If I was a Yamaha engineer I would never admit it. In the same years Honda made carburetors that did the same job, much more simple and capable. And, just to keep the record straight, I am both German and American.
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  14. Juvenile Senior

    Juvenile Senior Been here awhile

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    Disagree with whom exactly?
    Nobody argued about its being complicated.
    For no good reason?
    They had a very obvious reason, to try and create a cold start system that works gradually in several stages. Let us at least give them the credit for being experimental. We are speaking of 1982, when the scooter has been intrduced. How many other producers have already made their first attempts at electronic sensors, management and reciprocrative controll systems in their cars, bikes, not to mention scooters? This "oh so stupid" cold start system featured all that!
    Honda used the good old passiv electric choke that opens up if you run curent through it long enough. And by the way, does tend to fail over the years just as well.
    I would give more respect for an engineer that is ready to try new solutions and fails (and in this case they didnt even really fail), over the one who buys solutions off the shelf. That is what the difference between an engineer and a thechnician should be.
    Of course, you can just take proven components and stick them together and be successfull with it. Look at all these GY6 derivatives buzzing around us.
    Let us not forget that neither yamaha nor any other producer make their own carburetors. I suppose that either Mikuni had a new concept at the time and Yamaha agreed to try it, or Yamaha came up with a concept and Mikuni agreed to work with them on its development. What really happened then, we just don't know. Either way, there were obviously a bunch of creative smart engineers working around that system.
    Well I find it fascinating and am happy to own one exemplar of that ettempt.

    So, @Wentwest, I suppose your carburetor got clogged while riding? Or would you like to elaborate on what conditions clogged your carb and what component that is unique to that carb made it clogg so early? Assuming that what you are telling is that your carb got clogged within just a couple of weeks after beeing thorowly cleaned and while being regularly used?
  15. Wentwest

    Wentwest How's that work?

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    I understand experimentation and I understand your point that we should not criticize people exercising their imagination. That's true. I agree.

    What I don't agree with is the practice of trying an idea and when is sort of works, but not quite, adding another mechanism to the first. When that seems to get to the goal, but still not quite, add another system. The Yamaha carburetor looks like that. Whether it is that story or something else, I don't know. What I do know is that it is a complex way to deal with a set of problems and it's installed in a machine that is made to be sold to people as a utility appliance, not as a maintenance hobby.

    My story is I cleaned a Riva 180 carburetor carefully, with chemicals, ultrasound and compressed air as well as probing the passages. It started and ran well, and I used it for perhaps 150 miles of city travel. Then I was out of town for about 2 weeks, and when I came back it was very difficult to start the scooter. I took it all apart again and the tiny opening at the lower end of the passage from the bottom of the float bowl to the cold start system was blocked by a tiny piece of grit. The grit wasn't Yamaha's fault, but the tiny opening was. Honda had a carburetor with a cold start bystarter that was much simpler and much less sensitive.
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  16. Juvenile Senior

    Juvenile Senior Been here awhile

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    I see your point, that is indeed a constructional weakness. What I am learning from your story is that I need to make sure there is a fuel filter lined in, sooner than later.
    This constructional fault makes me think about the Colt M16 compared to the AK47. The former is a rather sofisticated mechanism, made of high tec alloys and plastics, whilst the latter just works. If I had to choose I would take the AK47 any day.

    Today I took the Cygnus for the best mainenace I know, some 80 Kms stretching from 950m to 400m above see level and back. That was partially a good Idea.
    First of all it was colder than I expected (the forecasts promissed 13 c), and second, I wasn't aware that the roads at the mountain tops had been salted already.
    So I froze my bones and now I have something to wash.
    But here are some impressions of our area.

    IMG_20191124_150431.jpg IMG_20191124_150358.jpg IMG_20191124_150111.jpg

    Enjoy the rest of your weekend!
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  17. Scootie Noob

    Scootie Noob n00b

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    Any update on your carburetor swap Simon?
  18. Kevinforesthill

    Kevinforesthill Been here awhile

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    That sure looks like a cold ride, but a nice one.
  19. Kevinforesthill

    Kevinforesthill Been here awhile

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    Ironically this is the exact story of my Honda 110cc engine problems (both my CT110 and ATC110). Damn thing clogs all the time because of my rusty gas tank and my paper fuel filter doesn't stop the microscopic junk that is able to clog that tiny pilot jet. The pilot jet on that carb is so small nothing will fit in it other than a wire wheel bristle ......I tried boiling it, propane torching it, and soaking it in carb cleaner for a week but nothing worked except for a wire wheel bristle (thank you google). The next time it happened I replaced the jet, the third time I wire bristled the jet, the 4th time I changed the jet and I haven't started it is a couple weeks so I will likely have to bristle or change the jet again.....and all of this was in the past 4 months for the ATC110, I haven't bothered with the CT110 since its pretty much a garage queen anyways.
  20. Juvenile Senior

    Juvenile Senior Been here awhile

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    Wow, well, I hope at least this carb is easier to access than on the Riva :-)