150 gy6 disappearing spark

[tylerpyatt]

I have a 08 Lance Milan scooter i bought used and it's been a real joy. After reading numerous posts on here about this engine stalling after a bit of running I've "fixed" a lot of different things. Now that I believe my fuel supply issue has been resolved I've either created another problem or just noticed it.

When I crank on it for a bit it tries to run. At first it will run like it's getting too much gas. After a bit it hits ever so often. Then after that it does nothing but crank over. (after this i test to find there is no spark)

After has sat overnight I pop the spark plug wire off and stick a spark plug in the boot and crank it a bit. It starts off with a nice spark and then it disappears. No spark at all.

I don't understand why when I start cranking it's there but after a few seconds it disappears. Hopefully it's something expensive.

Any suggestions??

Thanks

[edfr]

It could be any of the ignition parts Coil, CDI, Pickup Trigger by the Flywheel. If you have a Volt Meter you can test which one is not sending the juice. First though check all the connections to the CDI and to the Coil. The wires on the Coil make sure they are on nice and tight and not touching each other then check the connectios to the CDI and the wires from the CDI.

But It sounds like your CDI may be bad or your Pickup Trigger by the Flywheel that tells the CDI when to release the Voltage to the Coil.
Lefty

[sprocket]

I agree with Lefty.. but on a 2008 I would do the pick-up coil first. There were many that went bad from that year of manufacturer. It is also the cheapest part...

www.scrappydogscooters.com/125_150_4-STROKE_PARTS.html

Scroll down about 3/4 of the page.. It is called a GY6 ignition trigger pickup

[tylerpyatt]

thanks for the info. after reading through the forums about these ignition parts i figured them out and tested them with my handy multimeter. The pickup coil wasn't producing any current. Long story short, i fiddled with it and cut out a section of banged up wire and it works. I bought a new one on the internet to replace when it leaves me stranded miles from home.

Now my old problems have surfaced again. It idled nicely for about a minute until I gave it a bit of throttle. It quickly died and would not start back up. I'm not sure what can cause this. It wouldnt start back up after that. I'd say in the morning if I tried it would probably start up and do the same thing.

Earlier today i found a small brass piece laying in my driveway. Im afraid it belongs inside the carburetor. I can't quite tell what it is but hopefully it is the culprit to my disabled scooter there's a picture at this link> itchjuice.com/thing.jpg anyone have any idea what this is? Does it go in the carburetor?

i appreciate your guys' help. this forum is fantastic

[apittington]

I'm pretty sure that's the seat that goes under the main jet? or was it pilot jet? bah! been to long since I had my carb apart... under one of the jets. yeah.

Are you saying that when its cold and you start it, and then give it throttle it dies? Cuz that would be pretty normal, as giving it gas while cold (choke on) would flood it. Let it warm a bit.

Adrian

[rockynv]

Apr 20, 2011 2:42:24 GMT -5 apittington said:

I'm pretty sure that's the seat that goes under the main jet? or was it pilot jet? bah! been to long since I had my carb apart... under one of the jets. yeah.

Are you saying that when its cold and you start it, and then give it throttle it dies? Cuz that would be pretty normal, as giving it gas while cold (choke on) would flood it. Let it warm a bit.

Adrian

That is what it looks like to me. I call it the needle guide and seal because it goes between the main high speed jet and the bore of the carb and guides the metering needle on the slide through the jet.

[ericrockstar]

I had some/ having similar issues LOL! Intermittent spark, carb etc. I don't think you would have got the carb back together without the jet?
Clean you plug so it good and shiney and gap it right; mine was .035, I had to get another gapper as mine diddnt go that small. Make sure the metal socket part of plug is touching good ground when checking it.

[sprocket]

YUP I agree... part of the main jet seat... you are starting it on the idle circuit of the carb. As soon as you raise the throttle the engine is flooding without that part on the main jet...

[tylerpyatt]

Sure enough that piece belonged in there under/above the main jet. It runs great for a little bit. Now that i've replaced/repaired a number of things i'm back to the original problem that started it all.

I've been reading these forums quite religiously and i feel like ive about covered all the simple things i can handle. my problem is i can run for a bit but when i run around 40 and up it dies. If i stop for a few seconds it will run for a little while longer.

I want to think its having a hard time getting fuel to the carb but whenever i yank the fuel line off it spits gas out without a problem. Though there always seems to be a large bubble in the line from the carb to the fuel pump whenever it dies.

i've put a new mikuni pulse fuel pump on it, lowered the fuel pump from its original position well above the carb and tank. new fuel filter/spark plug, cleaned carb very well, and cleaned up the wiring.

is it possible the cdi or coil is to blame? i'm not sure if spark is the cause of this dieing as i cant check it because by the time i get to the spark plug wire the scooter would start anyway. I've read a number of similar posts and feel like ive done most everything but gap the valves. The thing runs perfectly except for the random dieing at about 40-55. Should i break down and buy a new cdi and coil and see what happens? Should i just give in and take my scooter, along with all my money, to a mechanic?

thanks

[sprocket]

I would replace the CDI first. They get tired and the capacitors get slow to charge. It could also be heat related...

If you are convinced you have fuel and the float is adjusted correctly then it is electrical. Ignition coils do go, but pick-up coils and CDI are far more common...

[ericrockstar]

Nonsense! Throw Parts at it! few weeks ago I got new CDI, Coil and a petcock on ebay for $30 shipped.
The other day I ordered a new carb with enricher for $30....It hasn't got here yet, but I'm feeling pretty good that it will cure my problems. A few bucks more and you can get the cool racing stuff. Don't know about actual performance but they have cool colors.

On a side note; I have no idea what the actual problem is with my scoot. It would probably fire right back up if I put the old parts back on...except the petcock. I know that was bad. And the prongs on my coil were all bent up? and it worked when it wanted to and sometimes not.

[tylerpyatt]

After shoving my multimeter in some different places i've determined i'm almost positive i've found the problem. I felt this way about the fuel filter, fuel pump, wiring, and vacuum lines, all which turned out not to be the problem.

After my scooter finally decided to start doing its dieing trick while sitting still i was able to check on some things. I attached a multimeter to the pickup coil. While it was running it produced its small voltage. However when it died it went away. I believe it died because that went to zero.

It should still make a voltage even if the engine was dieing (spinning down) since its voltage is made by the magnet/pickup coil setup. Am i correct there?

This also worked along with a spark plug attached outside. the spark intermittently quit along with the pickup coil voltage.

Hows that sound?

I think i ordered my pickup coil from china so i'm going to see about getting one from the u.s. and shipping that bad boy pretty quick. I'm ready to slap it on there and find out i diagnosed it wrong again.


Thanks for all the help guys.

tyler

[justbuggin]

if the pick up coil stop prducing a signal the motor can not run it take feul compresion and spark to make this thing run with no signal it will not have spark

[justbuggin]

oh by the way have you check the wiring to make sure that the kill wire is not grounding out it would be possiable

[tylerpyatt]

Great news! Bolted on a new pickup coil and my scooter has been running like a champ. 20 miles last night without even a stutter.

thanks for the help