Battle with My Riva 125

[bman]

Looks like you have easy access to AVgas. My carb issues (not a Riva) were totally solved by buying non ethanol gas.
Before switching over to non ethanol, if my bike sat more than 3 days it had carb issues.
Tried Seafoam but that did not seem to help. After cleaning the carb for the third time I drained the tank and filled with non ethanol, no more carb issues. Bike has sat for 2 weeks and still cranks at push of button.
Non ethanol is about 10cents a gallon more expensive here, but well worth it.

[hayasakiman]

I no longer use AVgas on my scoot. The regular gas from Costco is working fine now.

I truly believe the sticky stuff on the carb I had before was due to the use of MMO ( Marvel Mystery Oil) with breather tube connected. I ran scoot with AV gas and crankcase breather detached ( by mistake), and I didn't get any sticky stuff. Changed engine oil to an oil with no MMO added and breather tube connected, and I didn't get sticky stuff.

I now have the crankcase breather tube covered with a filter and is vented to outside. The hole on the air filter box is blocked with a plug. Added 3oz of MMO to engine oil as of yesterday. The scoot should be good for a while.

I have an easy access to AVgas but it is way too expensive. Using AVgas defy the purpose of riding the scoot.

I don't know where I can get non-ethanol gas in WPB area.

[bman]

Glad you got things sorted out. If it's your daily driver it probably doesn't matter if you use ethanol. Looks like you don't have too many choices for non ethanol according to this.

[JerryH]

Well I can say one thing. You are persistent. Most people would have given up long ago and hauled it to the landfill. It sounds like your scooter was not very well treated or maintained before you got it. I have a Yamaha Vino 125 that I bought new, which now has over 20,000 miles on it. It is still like new. I have never had a single problem with it, other than the fuel line and vacuum petcock. I have replaced the fuel line about 4 times, and have completely done away with the petcock. It was an inline design, in the fuel line between the tank and carb. I just ran a straight line from the tank to the carb. I can pinch it to shut off the fuel if I need to. Surprisingly the needle valve has not started leaking yet. Maybe it does not have a rubber tip on it like most of them.

Real gas is impossible to get around here. There is a marina about 20 miles away, but they only sell the 10% moonshine gas too. Local airport will not sell avgas unless you are putting it into an aircraft. The only source of real gas is the local dragstrip, and the stuff costs $9 a gallon, not an option. Ethanol gas is bad stuff. I am pretty sure it destroyed the plastic gas tanks on 2 honda dirt bikes. They developed cracks all over. It also turns rubber to mush. It will damage any rubber fuel line, vent line, and any rubber parts in the carb. It also tends to destroy the packing in manual petcocks and the diaphragm in vacuum petcocks. It melted the diaphragm in the fuel pump on my '72 Pinto.


If your scooter has any kind of emissions crap on it, I definitely recommend getting rid of that. The fuel tank should be vented directly to the atmosphere, no into a cannister. Make sure you carb float bowl vent is open. Make sure your crankcase vent is not restricted. Many bikes have a "separater" in the crankcase vent system, designed to separate liquid from vapor. There is usually a long tube with a plug on the end of it to catch the liquid, which is usually a combination of oil, gas, and water. It is commonly called a "puke tube" and needs to be drained every so often. Or you can just leave the plug off.

Unfortunately, motorcycles and scooters do not yet have positive crankcase ventilation systems like cars, they are usually vented to the airbox. Cars from 1962 on use actual engine vacuum to suck the vapors out of the crankcase. Don't know why this won't work with bikes. The Honda Met and Ruckus from 2002 through 2005 had a very poorly designed venting system, most of these engines did not make it past 10,000 miles. It was redesigned in 2006.

If the carb gets all gunked up again (it has to be engine oil, nothing else it could be. thats why I don't understand why spray carb cleaner would not dissolve it) try connecting a hose directly to the crankcase vent fitting, and leave the other end open. As was said, a single or 360 degree twin (which is basically a 2 cylinder single, both pistons rise and fall together) inhale and exhale through the crankcase vent. In a 180 degree twin, where one piston goes up while the other one goes down, they cancel each other out. They also don't vibrate as much. A more efficient design all around from an engineering perspective, but somewhat lacking in character.

[hayasakiman]

Originally Posted by bman

Glad you got things sorted out. If it's your daily driver it probably doesn't matter if you use ethanol. Looks like you don't have too many choices for non ethanol according to this.

Thank you for the link. According to that link, there's one gas station near to the airport I work at. I'm due for refill of a 5 gallon tank soon. I'll try the gas from that station, then.

[hayasakiman]

Originally Posted by JerryH

Well I can say one thing. You are persistent. Thank you.

Most people would have given up long ago and hauled it to the landfill. That was not my option.

It sounds like your scooter was not very well treated or maintained before you got it. The scoot looked OK and rode OK for about 300 miles.

I have a Yamaha Vino 125 that I bought new, which now has over 20,000 miles on it. It is still like new. I have never had a single problem with it, other than the fuel line and vacuum petcock. I have replaced the fuel line about 4 times, and have completely done away with the petcock. It was an in-line design, in the fuel line between the tank and carb. I just ran a straight line from the tank to the carb. I can pinch it to shut off the fuel if I need to. Surprisingly the needle valve has not started leaking yet. Maybe it does not have a rubber tip on it like most of them. You could buy an in-line fuel shut off valve.

Real gas is impossible to get around here. There is a marina about 20 miles away, but they only sell the 10% moonshine gas too. Local airport will not sell avgas unless you are putting it into an aircraft. The FBO in my airport doesn't mind of selling the AVgas as long as you come with proper jerry can for gas.

The only source of real gas is the local dragstrip, and the stuff costs $9 a gallon, not an option. And I thought the AVgas was expensive.

Ethanol gas is bad stuff. I am pretty sure it destroyed the plastic gas tanks on 2 honda dirt bikes. They developed cracks all over. It also turns rubber to mush. It will damage any rubber fuel line, vent line, and any rubber parts in the carb. It also tends to destroy the packing in manual petcocks and the diaphragm in vacuum petcocks. It melted the diaphragm in the fuel pump on my '72 Pinto.


If your scooter has any kind of emissions crap on it, I definitely recommend getting rid of that. The fuel tank should be vented directly to the atmosphere, no into a cannister. Well, the Riva has that canister.

Make sure you carb float bowl vent is open. Make sure your crankcase vent is not restricted. Many bikes have a "separater" in the crankcase vent system, designed to separate liquid from vapor. There is usually a long tube with a plug on the end of it to catch the liquid, which is usually a combination of oil, gas, and water. It is commonly called a "puke tube" and needs to be drained every so often. Or you can just leave the plug off.

Unfortunately, motorcycles and scooters do not yet have positive crankcase ventilation systems like cars, they are usually vented to the airbox. Cars from 1962 on use actual engine vacuum to suck the vapors out of the crankcase. Don't know why this won't work with bikes. Riva 125 has breather tube (crankcase venting tube) connected to the air intake box. Though, now, it is not connected on mine.

The Honda Met and Ruckus from 2002 through 2005 had a very poorly designed venting system, most of these engines did not make it past 10,000 miles. It was redesigned in 2006.

If the carb gets all gunked up again (it has to be engine oil, nothing else it could be. thats why I don't understand why spray carb cleaner would not dissolve it) try connecting a hose directly to the crankcase vent fitting, and leave the other end open. Yes, my breather tube has a filter and vented to open air.

As was said, a single or 360 degree twin (which is basically a 2 cylinder single, both pistons rise and fall together) inhale and exhale through the crankcase vent. In a 180 degree twin, where one piston goes up while the other one goes down, they cancel each other out. They also don't vibrate as much. A more efficient design all around from an engineering perspective, but somewhat lacking in character.

Thank you for your post.

[hexnut]

Wow, My 17 year old Cub Cadet lawn tractor must not have got the message on ethanol gas. I have used 10% ethanol gas in it since day one. It has the original carb, rubber fuel lines and plastic fuel tank. they are all in good shape. No deterioration what so ever.

This past summer I gave it a general clean up and took the carb off to have a look. The carb was clean as a pin with no build up of any kind. The thing runs perfect. It has an aluminum engine with overhead valves. I let it set over the winter months and it always starts up in the spring with out any problems.

Way too much hype on the net.

http://ag.utah.gov/divisions/regulat...t%20051910.pdf

[bman]

Nice that your lawnmower likes ethanol.
My KLR did too.
Unfortunately my SYM doesn't.
Could be some carbs are more sensitive to it.

[hayasakiman]

The piston diaphragm had stretched so bad that it didn't fit any more on my Buell's carb. I had to buy new one. Could it be due to ethanol???

Maybe.

[hayasakiman]

I'm day dreaming about having a disc brake on my Riva 125.

Which scooter has 10" wheel and disc brake so I could see on CL to source the front end?

[cheap bastard]

The Vino 125 and Zuma 125 are both disc equipped. The Riva sure could use better brakes.

[hayasakiman]

OK. Thank you.

Those two models are not so popular around here in So FL CL. But I'll keep looking.
Last thing I want to do is to go with Chinese clones even though they are dirt cheap.

[hayasakiman]

The solenoid installed before was functioning intermittently. I had to knock to make it work sometimes. No wonder it was free from a shop. So I bought replacement solenoid from auto parts store for $13. Installed it without bench testing it, thinking it is new. What could be wrong? Right?

http://shop.advanceautoparts.com/web...arter+solenoid#

Well, it didn't work. The coil is open, no continuity between the two small posts. I could returned it for another unit but I decided to have fun. Drilled out the rivets to open up the solenoid and found a problem. Soldered a wire to complete the coil. Re-assembled all back and it is working as it should on the bench. Installed it onto the scoot and still working.

Found some Vino 125 front end parts on eBay to entertain my idea of having disc brake on my Riva. But I think I have to let them go for now that I cannot afford them.

[hayasakiman]

My Riva 125 with Sunrise this morning.



$13 automotive starter solenoid works every single time for start up. I was thinking of buying the OEM solenoid from Yamaha if this one doesn't work. But so far so good that I don't have to spend $65 plus shipping for that.

[max57]

Originally Posted by JerryH

Real gas is impossible to get around here. There is a marina about 20 miles away, but they only sell the 10% moonshine gas too. Local airport will not sell avgas unless you are putting it into an aircraft. The only source of real gas is the local dragstrip, and the stuff costs $9 a gallon, not an option. Ethanol gas is bad stuff. I am pretty sure it destroyed the plastic gas tanks on 2 honda dirt bikes. They developed cracks all over. It also turns rubber to mush. It will damage any rubber fuel line, vent line, and any rubber parts in the carb. It also tends to destroy the packing in manual petcocks and the diaphragm in vacuum petcocks. It melted the diaphragm in the fuel pump on my '72 Pinto.




.

I have been wondering why I don't have ethanol problems. It's the rubber. My carburetor is an old Bing with no rubber parts except a rubber ring at the top, which doesn't touch fuel. And its octane requirements are low.