Out of Ideas for a Broken Vino Classic

[zzaach]

Hello all,

I bought a broken 2006 vino classic for $100 because I thought it would be fun to fix. All of the lights work and the starter sounds strong. I cleaned the carburetor and the pilot jet was completely clogged. I got it to where I could spray carb cleaner through it but I still couldn't get a wire through it. Even after I tried starting it 10 times, there was no fuel in the carburetor. 

I tested for spark. When I got the spark plug out with the boot, it was dry. I tried grounding it to the frame and starting the scooter. It kept sounding like it sparked once and then would kill the battery. 

Just now, I tried spraying Start Your Engine Spray into the air intake and connecting the fuel line to a bottle of gas mixed with starter fluid. No luck. 

Any advice would be appreciated because I'm about out of ideas. I am still suspicious of the carburetor. I assume I'm somehow incompetent testing the spark plug.

[jackrides]

Fix one thing at a time. Choose fuel or spark. Fuel: Start by being sure the whole fuel system is clean and petcock (fuel valve) flows fuel into the float bowl. Yes the pilot jet needs to be clean, but forcing a wire thru it could enlarge it, remove it to deal with it. What kind of carb is it? Any numbers? Spark: What do you mean 'then would kill the battery"?
Is the battery charged and terminals clean?
With the spark plug out & connected to the boot, hold or wire the side metal of the plug against a metal engine part and try to start it. If a second person is needed ask someone to help. Spark once, nonce(not at all), or continuous?

[Zino]

When you get to fuel
Check the fuel pet cock to see if it is flowing fuel by sucking on the vaccuum tube to the carb and having the the other tube flowing into a jug .
A thorough cleaning of the carb is needed these jets are easy to get varnished closed.
Boiling or ultrasonic cleaning.

The service manual is on here
www.motorscooterguide.net/Manuals/Yamaha_XC50_Service_Manual.pdf

[zzaach]

I cleaned the battery connections and now I have a continuous spark when I tested it. I tested the petcock and fuel went into the float bowl when I sucked on the vacuum line. I guess the problem is with the vacuum then. The intake manifold and hoses look like they're in good shape. However I did find a mystery hose that does not connect to the carb or anywhere I could find.

One thing I found that is concerning is the engine block has some spongy stuff and aluminum on the side of it. Also, the carb is a keihin 4 stroke carb with the numbers 3d1100.

Thanks for all the help!

URL to engine and mystery hose photo: imgur.com/a/xwvgxGV

[jackrides]

Wearing gloves, remove the spongy stuff, place in a secure baggy and send it to NASA for ID. After that, was that hose connected to anything? It is old, cracked and needs replacing. Is there a empty hose nipple on the intake manifold (the part between the carb and the engine)?
Question for everyone: Why is it called a manifold when there is only one opening on each end of it?

[Zino]

If the fuel flows when you suck on it .
You know its not the fuel petcock.
So it could be a clogged vaccuum tube or the fuel inlet tube on the carb could be clogged or the float on the carb could be stuck.
You could have the fuel line hooked to carb with the float bowl off suck on the vaccuum tube and see if you can turn on and off fuel flow by moving float up and down .
If that works you can move on to fuel flow from the bowl and see if it is getting through jets and nozzles.

The extra tube is probably just a carb overflow tube or a tube to drain the fuel bowl.

[Zino]

Keihn are quality carbs .
The stock is a mikuni so this carb has been added afterwards .

[GrumpyUnk]

Odds are that the orifice that feeds fuel to the 'by valve'(choke thingy) drilled into the side of the float bowl is blocked. Look into the float bowl, on the side with the enrichment mechanism(black plastic thing sticking up from the carb), and you will likely see a small hole or orifice drilled into the float bowl. That little hole allows fuel into the tube that surrounds the fuel pickup for the enricher(byvalve). If the carb sat long enough, that little hole can get plugged, and you will have no choke or enrichment function for cold starts.
You may be able to use a strand from a wire brush to poke through the orifice. Carb cleaner might remove a blockage, or air under pressure. Check that it allows fuel to flow, and if not, you won't have cold start help from the carb.
I read and re-read all the posts... As I understand, it won't start, but you have cranking, and you have spark when cranking. You should be able to squirt a tsp of fuel into the inlet of the carburetor, with the throttle wide open and the 'slide' moved up out of the way. That will saturate the intake plenum(or manifold) with fuel, enough that there should be a burnable mixture at some point in cranking the engine over for a few seconds. It should start and run for a few seconds, or at least pop pretty good as it is cranking. If not, check the valve clearance and also that the valves are not stuck. If it has been sitting, un-moving, for some time, the valves can get stuck and be open when the should not... and it won't run. Take off the cam/valve cover and crank the engine manually, while watching the valve springs which should move up and down as the rockers push on the valve stems. If one stays down, it needs to be freed up so it can move without binding. Sometimes manually moving the valve back and forth while applying solvent to the valve stem(through the intake/exhaust port and around the valve spring area) can get them to free up and move reliably. If they move ok, check that you have compression using a gauge or feel the resistance as you cycle the crankshaft over using the kick starter. You should be able to feel the compression stroke resistance.(along with that of compressing the valve springs)
 If this has the engine design I think it has, you should be able to access the valve adjustment through a couple ports.  If they are too tight, it might not want to fire, or will be hard to re-start when warmed up.  Normal wear will likely tighten the valve clearance, so checking it not a bad idea.
tom

[zzaach]

Thanks to everyone for there help! I got it running today!

I cleaned the carb again and the little hole GrumpyUnk mentioned and replaced the fuel and vacuum hoses. To get it started I sucked on the vacuum hose to refill the carb, sprayed starter fluid into the carb for 3 seconds, and kickstarted it.

There are still some more problems (high temperature warning light, speedometer not working, and a very high idle speed). I'll message yall if I can't figure them out.