It won't start!

[ideascape]

I have a Venox 250 which has been sitting over the winter. The engine turns over but won't start.

• It's not the battery; I've tried started it with a fresh car battery.
• I've loosened both carb drain screws. On one, a steady stream of gas flows out. On the other, nothing. Not sure what the next step is here.
• I found something amiss with a cylinder-shaped object (see attached picture). The straps holding it in place had rotted off, and it had fallen out of place. There was a loose tube sitting nearby which was not connected to anything and led to a different, similar cylinder; I connected it to the place my finger is touching, as it seemed to be the only logical place to connect it. Tried starting the bike again, no dice. There are a couple of other ports on it which are not connected to anything, but I didn't see any other disconnected tubes. What is this thing and how do I figure out whether it's set up right?
• The gas has been sitting in the tank for at least 8 months. I'm guessing I need to remove it and put fresh in. Should I remove the tank or is there some easier way to do this?

Any advice or suggestions would be appreciated. If I need to take the carb apart I will, but I haven't done that before and am hoping to avoid it. Thanks guys!

Edit: the image should be rotated so that the cylinder is vertical with my finger underneath it and the bike frame is at the top of the picture.

[zombie]

http://www.manualedereparatie.info/en/download/kymco-venox-250-Service-manual.html

That's the page for the manual
This is a site that will show you a parts breakdown. Just follow the prompts.

http://www.stadiumyamaha.com

Don't worry where everything goes yet cause you have to take it all apart to get the carbs out, and take them completely apart for cleaning. If you need help there post up.

Also just siphon the fuel out. When you refill add a couple oz.s of SeaFoam. Double the dose on the can. That will clean out the tank, and fuel lines for you. Order a new fuel filter, and spark plugs, and clean/replace the air filter.

It's a full days work the first time but you can do it all in 2 hours after that.

[ideascape]

Thanks for those links, the service manual is great to have. That seafoam also sounds like good stuff, I will definitely be getting some.

So you think I should bite the bullet and go ahead and take the carb apart and do the whole system. Hmm. Well, it's probably a good idea.

I will get a fuel filter and spark plugs. The air filter is newish but I will check it.

Should I get a carb rebuild kit like this: http://www.partsforscooters.com/180-149-Carburetor-Repair-Kit-250cc?sc=34&category=133078
or is that not necessary? Also, do I need to get a vacuum gauge for syncing the carbs or is that optional? Any other special equipment/supplies that I'm going to wish I had ordered when I start the project?

Thanks a bunch for your help, I'm still kind of a newbie when it comes to motorcycle maintenance.

[zombie]

I think it is a good idea to clean the carbs because you stated you are only getting fuel from one at the drain. That means at the very least one float valve is stuck, and at worst all the tiny passages are clogged up in both.

The carb gasket sets are pretty much a must have. The paper gets stuck, the rubber gets flattened or cracks, and it sucks to get part way thru, and have something leak.

Get yourself a set of torch tip cleaners at Ace Hardw. or most anywhere that sells tools.
http://www.homedepot.com/p/Lincoln-Electric-Oxygen-Acetylene-Torch-Tip-Cleaner-Kit-KH575/100341101

And a couple cans of Carb Clean. You will need to blow out Every port, and passage in the carbs.
Before taking out the idle mix, and speed screws... turn them both in, and count the turns until they lightly seat. This will give you a ball park setting when you put it back together.

The vacuum gauge will help but you have to find a vacuum source on each intake tract that is approx. the same. I've never tuned that bike so I can't say exactly where you can pick that up.

I find it easier to get the bike to idle, and adjust either carbs mix screw to the highest possible rpm, and compensate with that carbs speed screw. Once you get it as high as it will run turn that mix screw 1/8th - 1/4 turn richer. That is the optimum setting. Then repeat on the next carb. You'll find a vacuum gauge doesn't get it set as well because of small differences in pipe length, and cylinder condition. Once you get both carbs synced on the mix it is easy to sync the rpm of each cylinder.
Turn out both speed screws till the bike is barely idling. You will find you have to turn them down in steps so they sort of cancel each other out. Turning them back up is the same. You can hear when they are not fighting each other, and a smooth tone develops as they get closer to the same rpm. You want to hear a metronome effect. Not a Harley that just got fished out of a lake sound.

Hope it helps, and post up if you have any questions.

[max oradea]

if only one carb drains it might be that the bowl drain port on that carb is blocked but then again those ports are pretty big so i would suggest a carb strip and clean. everything else from that is easy. also check the plugs because it sounds like it might be flooded if you were able to get fuel out of the other bowl, but again that carb might have blocked jets if your plugs turn out to be dry.
while you are cleaning the carbs might as well change airfilter and oil, oil filter... everything! because it must be the start of the season for you. about the loose ends on pipes... you will get a better view of everything once you take the tank off, try to see where everything goes for example the loose ends and take some pictures before you start stripping.

[ideascape]

Pictures are definitely a good idea.

And the torch tip cleaner looks like a good thing to have.

Well, I'm sold on the carb rebuild. I'll order the supplies. Thanks again for your help, I'll let you know how it goes.

[zombie]

Please do. 

[Mike-the-Bike]

Those canisters are most of the nightmare emissions system, and are connected to the tank vents, carbs, the exhaust system, and each other.  If the bike was sitting all Winter, and the hoses are rotted or dis-connected, some insects may have made a home inside the hoses, and now air cannot pass through. Just my two cents worth.  Plus one on the sea foam, replacing the air & fuel filters, and cleaning the carbs. Good luck getting the top of the air box off them, however; I had to take mine to a mechanic after failing to get the thing off.

[max oradea]

the top cover of the airbox is a tight squeeze, forward and right if i remember correctly but really its tight. after that is off its simple!