Georges Francais

My '83 Riva 180 overhaul / EFI conversion!

My girlfriend wanted a scooter for some time and I was looking for a fun project in my new garage so when I saw this scooter on Kijiji for next to nothing I decided it would be my next restauration project. That strange retro-80's look was just the type of unusual bike I had to have. Plus a few years ago I restored a 1982 CB-750C so I guess I have a thing for that era. This is a picture of the beast when I brought it home in March. Very clean on the outside, with some scuff marks from a previous drop at some point. It's pretty low mileage (around 7,400 km) but I guess it was used on dirt roads a lot cause it was real dirty under the tupperware.

So it sat in the garage for a couple of months until all the spring chores around the house were done. Then I stripped it completely, and began cleaning every part thoroughly as I rebuilt it.

This is how dirty it was under the tupperware. And below is the powertrain assembly once off the frame.

With the powertrain off I started cleaning the outside with a soft wire brush, brake cleaner, some oil and a little WD-40 for good measure. I drained the oil and it was nice, no metal or anything, and replaced the filter. No metal there either.

Then I removed the crankcase cover #1 where the two clutches and the drive belt are hidden. I removed the two clutches and I thorougly cleaned the inside of the housing. Then I inspected the clutches, the weights, and the belt. Everyting was real nice, no visible wear, the weights were perfectly round, and the inside of the clutches was clean.

The drive belt was worn to 21.4 mm. Yamaha says that the belt should be between 22 mm and 20 mm, so it was good. But since I had bought a brand new one I replaced it anyway.

When I bought the scooter, I saw that the carb hoses were all messed up. Some were even sticking out of a hole drilled in the front cover, but it did not deter me since the price was right and compression was good. When I brought it home and began researching this gem on the internet, I realized that the carb was a nightmare so I decided to convert the bike to Electronic Fuel Injection. Some more research, and decided that the Ecotrons kit seemed like the best bet so I ordered it at once. This is a picture from their website showing what's included in the kit. The kit is very complete I think. I got all the items shown except the intake manifold because I did not order that version of the kit.

This is the original Godzilla-style carburetor that was on the Riva, and the cute little throttle body that was to replace it. I'd say the casting of the throttle body could be better, but it certainly will not affect the performance so I can't really complain.

Now since the throttle body is obviously smaller than the carburetor, I had to fill out the extra space in between the manifold and the airbox somehow. The throat of the throttle body itself is 28 mm just like the original carburetor, but it fits into a rubber boot that's molded onto the intake manifold. So I had to fabricate an adapter that would bolt on the flange of the throttle body, with the same outer diameter as the original carb. I used 6061-T6 aluminum for that, and I was allowed to use my cousin's lathe in exchange for a six pack of Budweiser.

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