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Post by spetz on Apr 13, 2011 12:10:57 GMT -5
First off - I'm a complete noob at scooter motors... After near 16 years of storage, I finally have my first scoot up and running. My sisters friend (a Harley mechanic), about 7 months ago, rebuilt the carb and had it running. This was in a different province (elevation change), and I never had a chance to ride it. I had it shipped out to me on the west coast, and because it was winter, it sat again for about 4 months. It used to go 100 kph (60 mph +) no problem, now it stops accelerating at 70 kph, even going down hill..just no power. So, these are the problems I've narrowed it down to...... 1. The fuel petcock was leaking onto the engine. I removed the inner diaphrams (2 - one per side of the centre plastic part), basically letting the free flow (it is so far impossible to find a replacement stock petcock for it). This stopped the leaking but I think it's leaking internally into the float bowl, causing it hard to start. Once it's started and warmed up, it runs ok. So the first question - Should I add a new petcock or is the hard starting caused by something else like the BCV, or is there a good replacement fuel petcock Riva owners are using? 2. The carb was redone months ago, but like I said, it has since sat for a few months. I intend on pulling the carb and giving it a good cleaning. On that note, I have pulled the new spark plug and noticed it was tan / light gray. AFAIK, this is due to running lean, correct ? I cannot find any adjustment screws on the Mikuni BS28 carb except the idle stop screw. Question 2 - Does this carb have to be adjusted internally for everything? 3. I intend on replacing all the hoses (Seems like 100 on the Riva.. ). to sort out any possible vacuum leaks. Question 3 - What type of hoses are recommended for this (IE fuel line hose, or something..)? I've seen red and blue ones on the forums here. I suspect all I have to match up is the internal sizing and length? Question 4 - Is there anything else that you can recommend I do to make it run better? I've heard of checking the rollers in the variator to make sure they aren't sticking. I have basic hand tools, but am willing try try anything. Further, it does not backfire, or bog down at all.. That's all for now.. Thanks in advance for any help you may throw my way. The red circle screw looks adjustable. I didn't see it there before under the crud. The hose closest to it I think is the vacuum as there is no fuel in it. I picked up new lines, carb cleaner fuel cut-off and inline filter today, now I just have to figure out how to remove the carb without damaging anything.
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Post by quest4fire on Apr 13, 2011 12:17:12 GMT -5
That scooter is a treasure. Treat it with love or let me buy it from you!
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Post by quest4fire on Apr 13, 2011 12:22:29 GMT -5
That said, it should go 70 mph easy. Take it slow and careful, get it right, there aren't very many of them. Get a new auto fuel valve if you need it. Wincycle in Miami is a good place. I sure wish that was my scooter. Lots of power. I test drove a Yamaha scooter at the 1985 Aspencade and was amazed at the subtle power. 55 anywhere, even a steep hill. And smooth. And I am a Heinkel driver!
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Post by spetz on Apr 13, 2011 12:43:29 GMT -5
That scooter is a treasure. Treat it with love or let me buy it from you! LOL--Thanks for the offer, but not for sale. It was a project between my father and I when I made it back home over the years. He passed 2 years ago, so decided it was time to get it up and running for good.. I know they are rare, but there are 2 others within 2 km's of me. One is a running 180 that's driven regularly (And I think for sale), and the other is for sale at a second hand shop, not sure if it's a 180 or 200 tho..
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Post by bigphillip79 on Apr 13, 2011 18:42:43 GMT -5
I'll try to get some pictures of my petcock when I get my Riva 180 back. I did away with everything vacuum operated and and went manual everything. Even the carb was swapped out. Its getting tuned by a carb guru. I rode it today and its a beast.
Anyway. for the petcock I removed it and made a blockoff plate out of 1/4 inch aluminum. Then I drilled and tapped a fuel opening in the center for a regular pipe fitting. I think it was like 1/4 inch. from there i put a 90 elbow with a regular ball valve and nipple for a 1/4 inch fuel line with a fuel filter. In the handle of the valve I drilled a little hole and made a rod to open and close the valve. Works like a champ and I can fix it with Home Depot parts. I think it cost $8 in parts.
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Post by quest4fire on Apr 13, 2011 20:19:28 GMT -5
I remember that the wheels come off easily on that scooter. Does the front wheel attach to just one side or just the rear one?
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Post by edfr on Apr 13, 2011 20:37:26 GMT -5
Does your carb on there look like this if so the Fuel Mixture is on top. Lefty
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Post by bigphillip79 on Apr 13, 2011 23:07:32 GMT -5
I remember that the wheels come off easily on that scooter. Does the front wheel attach to just one side or just the rear one? The 180s have single sided fork the 200s have double sided. The 180s are gravy to remove wheels.
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Post by spetz on Apr 15, 2011 11:16:02 GMT -5
Nobody else has any ideas ?
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Post by edfr on Apr 15, 2011 13:25:26 GMT -5
Spetz, How about answering some of the questions? I put up a picture of a carb and asked if that is what yours looks like. Better yet if you could put up a picture of your carb that would help a lot. There are to many different kinds of carbs out there and everyone is a little different. So help us help you Lefty
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Post by spetz on Apr 15, 2011 14:42:07 GMT -5
My bad..I actually thought I had posted in reference to your pic. It doesn't really look like your picture. I will take a some pics of it after work and post them here. It's still attached to the engine as I am trying to track down new hoses etc, before I remove it for a good cleaning (first time doing it..hopefully all goes ok).
I did notice last night that there are 2 "ports" for lack of a better word on it that have no hoses attached to them, both located on the bottom.
As well, I cannot see any screws on the top that seem adjustable except the throttle / idle screw attached to the actually throttle pulley. There is one brass capped screw on the left side (while on the scoot driving) that'll I'll have to drill out to get access too, but it is unaccessable unless the carb is removed due the frame.
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Post by spetz on Apr 15, 2011 21:17:01 GMT -5
Pics added to first post
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Post by dickie70 on Apr 16, 2011 16:12:26 GMT -5
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Post by dickie70 on Apr 16, 2011 16:21:58 GMT -5
I'm having carb issues with my newly acquired Riva 180. After I bypassed the BCV I realized nearly every vac line on the carb was hooked up incorrectly. I'll prob pull the motor and replace them all after I clean the carb. The previous owner said the carb was recently cleaned, but if the same clowns that cleaned the carb reinstalled the vac lines, I seriously doubt the did a good job.
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Post by spetz on Apr 16, 2011 21:59:38 GMT -5
Dickie...Could you tell me how to bypass the BCV? I think this might be the cause of my hard starting and think that's my last problem.
I stripped it down today, cleaned the carb and put it all back together. The carb was actually very clean, but there was some rust specs in the bottom of the float bowl and the rubber diaphram on the top was off on one side. I put it all back together and adjusted as per a post on here, it hit 95kph with no problems, but I ran out of road (only had about 200 meters down down a slight hill) . It pulls VERY HARD now compared to last week. I do believe the air fuel mixture was off as I richened it 2 turns. Completely different machine now.
Fast question tho ..... The drain plug on the bottom of the carb- should that be open? It is completely closed on mine. What I'm thinking is that either the fuel isn't draining from the float bowl when it's shut down and therefore flooding it making it hard to start, OR the BCV is making it hard to start..
Hopefully it'll start ok in the morning.....
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Post by quest4fire on Apr 17, 2011 5:43:36 GMT -5
The drain plug should be closed.
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Post by dickie70 on Apr 17, 2011 16:03:10 GMT -5
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Post by dickie70 on Apr 17, 2011 16:05:37 GMT -5
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Post by edfr on Apr 17, 2011 16:22:26 GMT -5
Spetz, That screw that is on top of the carb by the INTAKE manifold is Your Fuel Ratio Screw. So that controls how much fuel comes out of your PILOT JET for starting and adjusting the right amount of fuel to the air coming in. Counter Clockwise lets more fuel in and Clockwise less fuel in. Lefty
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Post by bigphillip79 on Apr 17, 2011 18:15:33 GMT -5
If your getting rust in the bowl the tank haas some rust. those scoots didn't come with a fuel filter so you want to add one. $3 for NAPA #3011. Just about every parts house will have that filter or a very similar one. It will save you later.
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Post by sprocket on Apr 17, 2011 19:14:42 GMT -5
That filter could be a problem on a gravity feed system. You should only use filters designed for these systems... Often the filter papers in automotive filters is too thick and scooters will run dry at WOT... I like the Visu filters but good old Briggs and Stratton are just as good... Visu Filters here: www.bikebandit.com/brand/visu-filterAttachments:
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Post by spetz on Apr 18, 2011 0:32:39 GMT -5
Well, heres what I've done so far.
1. Opened the carb. The top rubber diaphram was half off. I put it back on. As well cleaned the dirt from the float bowl. Put the carb back on.
2. Replaced the single fuel and vacuum line. I added a manual cutoff and inline motorcycle filter to the fuel line.
3. Fixed the fuel gauge. I took it out and took the rust off it and made it all shiny again and now it works. I also took the fuel petcock completely out and there is a built in, in tank fuel filter. Mine had rust on the screen so cleaned that all out. I also removed the tank and cleaned it.
4. Checked cvt belt and it's fine. Tried to check variater but I don't have a 24 mm. Also changed the oil and filter again (twice in one week to make sure after it sat for so long - Filled with 10w40 Motorcycle 4 stroke oil).
5. I adjusted the top screw ( the fuel screw for starting as per above) and did notice it's a bit easier to start but something I did sure helped, it goes like a scalded cat now.
I just have to work on the hard starting and all is good. I guess that means there is another screw on the carb that I haven't found.
Edit ** Fixed mistakes from iPhone entry
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Post by spetz on Apr 18, 2011 0:39:16 GMT -5
I've checked this out a few times, thanks. But the 180 and 200 carbs and hose routing are completely different. I only have a single vacuum and a single fuel hose on the whole scoot. Unless I'm missing something.
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Post by edfr on Apr 18, 2011 0:46:03 GMT -5
Spetz, I am looking at your carb and it looks like it has a AUTO ENRICHER(CHOKE) the black piece on the Opposite side where the Throttle cable is should have two wires coming from it. Check if it is plug in at the other end. When the engine starts it should get pretty warm that is when it gets Voltage. You can check if it works by taking it out and putting 12v to the wires the Plunger Should be RETRACTED by Default and as it heats up the Plunger should EXTEND to shut off the extra fuel. If that is NOT working it will cause you hard COLD STARTS. Lefty
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Post by quest4fire on Apr 18, 2011 4:34:31 GMT -5
I remember that the wheels come off easily on that scooter. Does the front wheel attach to just one side or just the rear one? The 180s have single sided fork the 200s have double sided. The 180s are gravy to remove wheels. That was good design. Gone forever.
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Post by spetz on Apr 18, 2011 11:45:02 GMT -5
Lefty (EDFR), thanks for the info, I thought that that might have something to do with it. This morning I left for work in the Jeep, but ended up coming back home because I forgot something, so decided to take the scoot instead. The temp was +2'C. I figured, what the hell, let's see if it starts.
I cracked the throttle about 1/8 of the way, turned it over and it started in about 4 seconds !!! Went straight into a nice easy idle !! Heck of a difference from last week when it would take near 10 minutes to start..
I guess everything is working as it should now, I may play a little bit more with the starting jet / fuel thing on the front of the carb.
Thanks everyone for your help in this ! Now I know how easy it is to work on this thing, there is nothing saying it won't last for another 10 years !
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Post by edfr on Apr 18, 2011 18:16:36 GMT -5
Spetz, Great to hear your vintage scoot is running good, Ride Safe they don't make them like that anymore. Just like the VWs body will fall right off the frame but that little engine would run and run. Lefty
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Post by spetz on Apr 18, 2011 21:23:52 GMT -5
Hehe. Opened it up on the way home from work on the highway. Went just over 110 kph before I hit an uphill section.
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Post by dickie70 on Apr 19, 2011 10:53:37 GMT -5
I could use some help with my Riva 180 also. I recently replaced all the vac hoses after I by-passed the BCV. It became apparant that something wasn't right after the petcock in the bypass line caused the engine to stall when open. I checked the vac hose routing using the diagrams from jacksscootershop.com and found out they were all screwed up. Fixed now. I also came across a bare nipple on the right side of the carb that is not discussed in any of the diagrams I've seen. I thing its the 4th pic in this album, behind the shinny black hose and to the left of the clear vent line, s1226.photobucket.com/albums/ee420/dickie70/ any ideas what this attaches to Still hard to start cold and takes a long time to idle smoothly after start. At least the petcock in the BCV bypass line is working as it should now. Full open for cold start and slowly close as engine warms up. I also have a lean backfire on deceleration. I was hoping it was caused by a small hole in the muffler so I patched and painted it, still backfiring. I shot a spray of carb cleaner near the intake manifold and I think I found my problem. The RPMs came up slightly. The rubber intake boot it old and a little rotted. New one is VERY EXPENSIVE. Any ideas? Does anyone know where I can get a copy of the maitenance manual in PDF? That would be awesome.
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Post by sprocket on Apr 19, 2011 11:53:53 GMT -5
You can try and repair the intake boot using High Heat Red Silicone...I have done this a number of times and you can get a year or two out of them. Use it liberally inside and out, but be certain the inside is a smooth as you can get it...
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