How about that! :D I was right all the long!

[YellowScooter]

For the past couple years, I was battling with my scooter over this seemingly incurable problem with intermittent power loss and unexplained engine bogging. I searched every english speaking scooter forum for the answer to this issue all to no avail. Everybody kept saying it was in the carburator and/or fuel delivery. I replaced the entire fuel delivery system from the tank forward, some parts a couple times.
I kept thinking in the back of my mind that it was in the CDI and/or ignition coil. But all the backyard and commercial experts alike dismissed it saying that the CDI was like a lightbulb. It either works or it doesn't work. After enough people said that to me time and again, I too dismissed it.
Just the other day, I tried to start up my scooter and run it a little bit and it wouldn't start. Pulled the plug and checked for spark, none to be found. So I called around looking for a CDI and coil. I found a CDI box just a few miles from the house, so I went to the shop and snatched it up. I never did find a coil, but as it turns out, the one I got is just fine. .
After I plugged in the ignition brain, I crossed my fingers and hit the button. The scooter fires right up, idles beautifully, and get this:
positively no engine bogging!
My scoot has full smooth power all the time, no bogging, no surging, no spark-knocking, & it takes right off cold or warm. It's like I got a brand new freshly tuned scooter!
So I have 2years of solid testimonial proof that the CDI is NOT one of those it-works-or-its-blown type of part. It indeed can reak mild to moderate havoc on overall engine performance before going out completly.

[tortoise]

Jan 9, 2009 9:23:24 GMT -5 YellowScooter said:

I kept thinking in the back of my mind that it was in the CDI and/or ignition coil. But all the backyard and commercial experts alike dismissed it saying that the CDI was like a lightbulb. It either works or it doesn't work. After enough people said that to me time and again, I too dismissed it.

Several members have suggesting the ice trick.

[earlwb]

I keep a spare CDI and coil handy to use for test purposes. No fuss no mess. You plug it in and see what happens.
I was taught to leave the carb alone. it is usually not the problem most of the time.

[dogmeat]

Hummmm thats a good find sir.

I think I may put back my stock cdi and see if it helps mine at all.

It still boggs at mid range sometimes.

[nicko31]

Jan 9, 2009 12:41:33 GMT -5 tortoise said:

Jan 9, 2009 9:23:24 GMT -5 YellowScooter said:

I kept thinking in the back of my mind that it was in the CDI and/or ignition coil. But all the backyard and commercial experts alike dismissed it saying that the CDI was like a lightbulb. It either works or it doesn't work. After enough people said that to me time and again, I too dismissed it.

Several members have suggesting the ice trick.

What's the ice trick??

[harrywr2]

Jan 9, 2009 17:53:27 GMT -5 nicko31 said:

What's the ice trick??

CDI's have micro-chips in them. It is not uncommon for a micro chip to develop heat related stress fractures that only show up when they are warm. Strapping an ice pack to a CDI as a way of ruling in or out the CDI is 'The Ice Trick'.

If your problem goes away with Ice strapped to your CDI then your CDI has stress fractures that only show up when it is warm.

[jake318]

yellow in Most cases the Cdi is a light switch situation . they can get goofy but it is unlikely . you just had the unfortunate oddball . Jake

[nikolai]

I'm with earl on this one --- leave the carb alone. I changed my CDI twice last year, the second one was go/no go thing so it was relatively easy to fix, unlike the the first CDI, which gave me hard-starting problems that got worse and worse, to the point that the bike only fired up with the kickstarter... that led me to believe that the battery was bad, so I got a new battery, but the bike still only fired up with the kick starter... a new CDI did the trick.

[oldkid]

Yellowscooter, I would have suggested you try another CDI. I placed several threads earlier about a miss in the engine of my Bali 150. It just felt like the ignition was cutting in and out at steady speed of about 45 mph. The tech. at my dealer said he thought it was the CDI and sent one. The new one stopped all the miss.
Glad you got it fixed, but as you said, they don't always quit all the way.

[shookupart]

yellowscooter. Thanks for this post, I cant give you a bone yet cuz I just gave one to earlwb a minute ago. My scooter has a subtle, intermittent miss or hesitation at high speeds or above 7000 rpm. I ordered a new coil- it has a brand new iridium plug. I have a race cdi from mrp in the package still but im wondering if a new (less expensive) cdi will fix the skipping. Is it rev limited this soon on the tach- between 7000-8000 rpm? I will find out and fix and thanks for this post as it has been very educational.

[YellowScooter]

Jan 9, 2009 13:58:57 GMT -5 earlwb said:

I keep a spare CDI and coil handy to use for test purposes. No fuss no mess. You plug it in and see what happens.
I was taught to leave the carb alone. it is usually not the problem most of the time.

Speaking of carbs, I had noticed something today as I was changing the oil on it. The mix screw is turned all the way shut tight. (and yes it's definatly the idle screw not the drain screw) I don't remember touching it before, but when I turned it out like it was supposed to be, It was barely 500ft before I was stalled off the side of the road with gas leaking out the airbox from the carb throat!
I closed off the idle mix screw, drained the carb bowl and it fired back up.
WTF?