More Starting Problems

[bjg]

Hi Everyone,

First off, my scooter does start. It's just that it can be difficult to start at times. Once started, it runs smoothly with good acceleration and good performance getting on and off the throttle. Idle is solid too. I don't have a tachometer for it but I have it set up so it's just a little below where the rear tire starts to spin and it idles cleanly on the stand or stopped at a traffic light.

The battery is strong at over 13 volts and the charging ciruit is working correctly. The starter cranks easily but it seems like the engine is starved of gas. If I goose the throttle a little while I'm trying to turn it over the engine sound changes as though its about to start but it doesn't. Sometimes it starts on the first attempt other times it can take 4-5 attemps before it starts (5-6 seconds of cranking each time).

I've done the PDI on this site and I have all new vacuum and fuel lines. I'm mechanically inclined but new to single cylinder 4 strokes. I'm just not sure where to go with this next.

I was thinking it might be the autochoke/enricher but it will do this hot or cold. I was also thinking it might be the fuel/air mix but I've checked my carb over several times and there is no adjustment screw for that. I understand that sometimes there is a port that is plugged and you have to remove the plug to see the adjustment screw but mine truly doesn't have even a plugged port.

Anyway, if anyone has any thoughts on this I'd appreciate it. It's more of an annoyance at this point but I want to get it to where it starts easily all the time. Thanks!

[jcz775]

Take 4 or maybe 5 boxes of buck shot and go nuts on it.

[richardthescooter1]

Hey big, I've had trouble with mine starting and come to found out each time this happend its alway related to vacuum leak, my intake clamp was coming loose and I even had a lock washer on it and I was looking at everything but that, so now when its giving trouble (yup, intake coming loose again) when there is a leak, your scoot will be too lean. just I thought Another thing that happened to me was the spark plug cap was coming loose and the wire inside the spark plug cap was pushed a side not making contact. These are the two things I look at when having trouble

[WarrenS]

Don't open the throttle or goose it while turning over. This just lets more air in. It may lose its prime so you need to crank more. Make sure the fuel filter is pointed the right way.

[bjg]

I have a vacuum gage I can put on the vacuum system. What should the vacuum be? Should it be stable or pulsing?

The arrow on my fuel filter points towards the carb and I don't have any fuel leaks so that should be ok. I thought the carb bowl stayed full (up to the float anyway) all the time. It shouldn't be able to drain back right? Should I go with an electric fuel pump like some of the people in the mods section have done?

Thanks again for the inputs.

[scootnwinn]

You said you set the idle to just a little less than the wheel spinning. I think that is your problem, the idle is too high. So what happens is the mix is too rich at a start up. There should be a few hundred rpm between your idle and the point at which the clutch engages. The reason it starts fine sometimes is that the engine may need a little more fuel sometimes. Turn your idle down I'm not sure what kind of bike you have but on my Burgman the idle is set at 1400-1600rpm and the clutch engages somewhere around 2600rpm. If yours is idling just under wheel spin it is set way to high.

Just a thought

[bjg]

Ok I can try turning down the idle a bit. I had adjusted it up because of rough idle/starting issues previously. I don't have an inductive tach so didn't have any way to measure RPM. I had read from several sites (including this one...I think) that many people set the idle to just below wheel spin. Maybe it's time to add to my toolbox.

[bjg]

Ok, I picked up an inductive tach and adjusted my warm idle down to ~1500-1600rpm. I went for a ride with the new idle setting and everything seemed fine (normal top end and no stalling or rough running at stop lights) but the next morning my scooter wont start at all. It cranks ok but won't turn over. The only change I made was turning the idle down ~1/8 to 1/4 turn. This is getting frustrating. Anyone have any idea what is going on here?

[scootnwinn]

Bad fuel enrichener?? Have you checked to see if it works

[bjg]

I know it gets voltage and gets warm. If I understand it right, when it heats up it pushes a pin in place to seal off a port. What would i look for to see if it is working?

[zfjelstad]

How's your fuel filter? When was the last time it was changed? I changed mine and it did wonders for me. I have an Roketa 250b and I agree with you that the idle should be set just below back wheel spinning. My idle is set at about 1900-2000 and it starts up just fine. It sounds like you are maybe having some flooding issues, so definitely check the enricher as scootnwinn said, but also a trick that I used to get a flooded scooter started is just to change out the spark plug with another dry one. It should fire right up.

You could also check the position of your main carb needle. There is a thread in the how-to section connected to the home page.

[scootnwinn]

You can test your enrichener by uninstalling it and grounding the body somehow and watching to make sure it moves... if its anything like an automotive one