Scooter dies when it warms up

[DarlaM]

When we start the scooter it runs fine, then after a few miles (seemingly after it warms up) it dies and will not start again. After it sits a day it will start back up again. We have been stranded all over the place. Thought we needed to change out the spark plugs but have since realized that with or without new plugs after sitting for awhile it will once again start (and then strand us again.) Anyone have this problem? We have ordered a new coil hoping that will solve the problem. We already brought it in once and were misdiagnosed from the dealer. We are hoping someone else might have some information on this. Thank you so much. DarlaM

[reknauk]

ive been having this problem as well a wile now replaced all topend gaskets and still the same have you had any luck locating the problem? plzzzzzzzzzzzz help anyone.

[Error No usernames avail]

I believe someone posted a while back something about using a hotter plug. Might want to try that

[micah apriliaforum com]

What model scooter? It sounds as though you may have an air leak at either the carb....bad reeds....bad jetting,,,clogged pilot circuit in carb?

[nycaprilia]

I too have this problem. Changed the plug, worked fine for miles. Park it, try to restart, it sputters and dies. The spark plug is getting gunked, but why. The model is Scar. 50 carb. model. I checked the air filter, and it is dry(need to add oil), as some post suggested that the air filter may over soaked in oil and leads to the clogged plug. Another question, I see clean (2 cycle pinkish in color) oil around the air intake of the carb. How does oil get there? The entire opening is covered by the air filter, which was bone dry. Getting stranded getting tired!

[ScooterWitch]

When this happened to my scoot, it was because of a teeny-weeny hole in the oil line. It was barely noticable, but it made a big difference in the engine. When it got too hot without enough oil, it just died. Even while I was moving. Might wanna check that out. Couldn't hurt.

[nycaprilia]

Is this the line from the oil resevoir? so this means taking out the battery box and looking for "wet spots"? hopefully this weekend, and the weather will be better also. In preperation for many engine checks, I bot a bunch of latex gloves and can of de-greaser. <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/ohwell.gif ALT=":\">

[jj008]

ncyaprilia,

It sounds like it is running way to rich. That is probably why it runs well when you first start it and at WOT. But when you stop and restart it there is too much fuel entering the cylinder and won't fire. Which is why the spark plug looks gunked up.

When you first start your bike do you have to use the choke?
if no then it is running rich.

Did the problem start after removing the airbox to check the filter?
If yes, make sure the rubber tube that goes into the airbox is not pinched. This would also make the performance of the bike seem slow and cause the bike to run rich. Hence a lower top speed. This happened to me on my 'beo.

The oil line goes directly into the carb.

[nycaprilia]

HeyJJ, thks for your suggestions. I didn't notice a tube going to airbox. Only two openings and air-filter access slot. Openings are: one going to carb, other is snorkel draw in air. Inbetween is filter. I'll check again

[jj008]

On the airbox side of the carb there is a tube 1 1/2" that is clamp to the carb opening with a 90 degree angle that fits into the airbox. That tube (hose) can be pressed together or press against the inside of the airbox restricting air flow. When this happened to my bike it wouldn't go over 35mph.

I need more info about when it started to happen. Did it start after servicing or weeks afterwards?

My guess right now is the choke isn't fully disengaging and that is why it is running rich and fouling plugs.

[nycaprilia]

So, the latest on gunked plugs. Turns out it's not the plugs, but I haven't solved the problem completely. Here's how it got working again. Took down the airbox. I adjusted a recessed screw on the carb. located just in front of the opening to air intake. This is not the idle screw, which is a bit to the left. It was down tight. I don't know what the purpose of this screw was, but turning it counter-clock wise evened out the engine. Made it stop sputtering. I removed the spark plug and sprayed starting fluid into the cylinder, replaced the plug, and the engine came back strong and ran all day. When the engine was parked briefly, it started up right away, but did give some problems if parked for a few hours. But I'm not as terrified of getting stuck as before. So, the problem is gas not getting into the cylinder. Someone here posted that an inline vaccuum valve on the fuel line would be the fix. Is there a specific name for this? Strauss auto parts said they never heard of it. So two questions: has anyone else had success with the inline valve and what does that darn screw do? Thanks. p.s i'm slowely getting tools as I progress, and the most convenient one is the 'T" wrench attached to a sparkplug (13/16) socket. $5.99 What a lifesaver!

[Dutch Royal T]

The screw you "found" is the air screw and is very important: it also tweeks your mixture and from experience: how it picks up from off-on throttle.

[Dutch Royal T]

I think you mean the vaccuum line.

That line operates the fuel valve which is mounted under the fueltank.

It uses the engine vaccuum to open and close the fuel valve. So if that line is broken or left off, the fuel valve won't open and no fuel will get into the carb's float bowl. So when the little bit in there is used up, the engine will stop running.

[jj008]

On the Scarabeo there already is a sparkplug socket. You use the srew driver as a T bar. Also the mixture screw should be 1 1/2 out for a stock scarabeo. You don't need to remove the air box either to adjust it. Just take off the service panel.

I believe that all the way in on the mixture screw means it is lean. Turning it out richens the mixture. I think I am right on this but somebody might want to correct me if I am wrong.

[nycaprilia]

Great responses!, Dutch, so if it's the vaccuum line, would (inadequate suction) that give problems starting, after the bike has been resting a while? The engine runs fine once started, and starts right up if it hasn't rested too long.

JJ, I bot the bike used, but good to know that the tool came with the bike, and right u r about the airbox. But I removed it primarily to let some light in ( so cramped in there). Thanks

[jj008]

The vacuum valve is located below the tank and isn't the problem to your starting problems. The carb is full of gas when you shut it off. If the vacumm valve was faulty you wouldn't be able to start or run the scooter. I would suspect the mixture screw needs to be adjusted to stock spec.

I have this scary feeling that your choke is out of adjustment and is partially staying on. That is probably why the mixture screw was turned all the way in. The person was probably trying to lean it out. That is the only thing I can think of that could be causing the black, fouled up spark plugs.

[lperkin6]

Mine is having the same problem. Running till hot and then only running with the choke on for a little longer. A service man told me it might be reed valves. Does this sound right?

[MikeT]

No - if it was the reeds it wouldn't run at all...

[lperkin6]

I finally found the problem on my scooter a few months back. Sorry about not updating you guys. The vacuum fuel tap was broken and just barely dripping. After it would run the gas out of the line it would die. About the same time it heated up, which caused my confusion.