Motor Scooter problems

spacerobot

I have a 1978 Yamaha Chappy, that used to drive pretty well. Towards the end of last fall (before it got cold) I was experiencing this problem, and now I have the bike out again for the spring, the problem seems to have gotten worse. Here's the problem:
I can kick start the bike just fine. It starts up in neutral and sounds great. When I put it into gear, the idle dies down, and when I give it gas (in gear) it stalls and tries to die unless I "pump" the throttle. This happens until the bike warms up after several minutes. So pretty much, the bike dies when I open the throttle, but runs fine when idling in neutral, until it is warmed up.

Any advice? Thanks!

VeritasVR

Possibly the idling speed of your engine. A mechanic would know how to increase it, because if the speed goes below a certain rate then the engine shuts off.

Everywhereasign

I used to have a moped (until it got stolen) that did the same thing. Tweaking the idle speed worked, but made the "bike" louder at idle, which I didn't like. I used to let it idle for a minute or two after starting. Then it worked fine, without all the stalling.

spacerobot

It doesn't seem like a problem with the idle, because it dies only when I give it gas. It's starting to get to the point where it takes longer to "warm up" than it does to get to my destination.

Munacra

Have you tried adjusting the idle screw a little tighter?

spacerobot

I have not. I'm not sure where I would find that at... Have any links to diagrams or drawings (or an awesome description)?

Also, last night when I got off of work I fiddle around with the fuel line and other tubes, and slightly re-arranged them so they werent going around any tight corners on the bike. I don't think I really changed very much, but today the didn't have the problem. So I don't know. I'll still try changing the idle though.

Munacra

Give me the model and make of your scooter.

RedDawn

Sounds to me like a carburetor problem. I had a few bikes that ran like that that had clogged air jets. If it has an automatic ckoke, it may be those jets are clogged up. I would try running a carb cleaner through a tank of gas to see if that helps.

spacerobot

It's a 1978 Yamaha Chappy.
I've read other places about the air jets (even though I have no clue what that is) and the carburater. Is the carb cleaner just a liquid that I can get at any automotive store?

Munacra

Oh man, I don't have experience with one of those. Do you have the owner's manual somewhere? Usually the idle screw is right under the fuel tank, on the left side, and is part of the engine. It has a phillips head and it also works like a knob for you to adjust with your fingers.

Some people never adjust their idle screws when it should be done at least twice a week. If not more.

But since I have not messed with that model of a scooter, I think you should take it to a mechanic and see what he says.

RedDawn

On my motorcycle, I run through a product called Sea Foam. It seems to do a pretty good job.

Here is a link to their about page for their engine treater. And yeah it can be picked up at just about any automotive store.