No start condition has spark/fuel/compression.

[micscience]

My scooter was giving a symptom of a hiccup and it was getting harder to start. So I cleaned the carburetor started it once and ever since I have been unable to start it. I have sprayed starting fluid into the piston chamber. I have verified spark which it looks good. I tested the compression with two compression testers. The only resemblance I got of a start was a few flames shooting out of the exhaust and that was it.

I did notice as I was cranking when I turned the throttle it would slow down the cranking process but I think that is normal because the opening of the carb throttle plate allows more into the engine which in turn increases the compression. I haven't had a chance to open the engine up since I have been really busy. I did get around to setting the valve lash clearance and nothing changed.

One thing that comes to mind is my harbor freight compression tester tested at 60psi and my better compression tool tested at 120psi with the throttle open and 100psi throttle closed.

Any suggestions are welcome I'm looking for some short cuts to avoid spending time I don't have combing through everything trying to find what the hell is going on.

Thanks in advance!

[GrumpyUnk]

I would suggest your carburetor is out of adjustment. It may be that the pilot jet has gotten plugged during the cleaning process. The opening is too small for a straight pin to go through.
The carb depends on the pilot for starting, in addition to the enrichment electrical valve. If the idle circuit is messed, it becomes very difficult to start. If you open the throttle plate too much, the engine will try to use the mid-range circuits to start and that's not easy.
I think I would take another look at the carburetor.
tom

[micscience]

Well I did try to insert a steel wire from a wire brush into the pilot jet. I was unable to get it through but I did get it in from one side andf I blew air through it and I actually cleaned the carb twice within 3 days since all this happened after the carb cleaning. The thing is though is I sprayed the engine directly with starting fluid I should have gotten something. I will look again and swap carbs just to see if there is a difference. Thanks

[tocoo]

when the carb is cleaned, you can use some carb cleaner at the air entry of the carb. You can also check the gap of your spark plug. My manual says the gap is good between 0,6mm and 0,7mm, but I gap mine at 0,55mm with feeler gauge.
Check that the mixture screw is between 1,5 and 3 turns from the screwed position.

Before starting the engine, wether with the kick or the battery, you turn the key OFF and you can kick a few times (and you go all the way with the kick, which is a bit beyond the foot parallel with the earth), and leave the kick at the highest compression. then key is ON, and you either kick while opening the throttle, or you start on the battery.

you can also check the electrical choke like here www.youtube.com/watch?v=IVLHaVPf7SI

[GrumpyUnk]

If you spray starting fluid, remember that it is a vapor almost immediately, and will waft away with the slightest breeze. Have you tried opening the throttle plate butterfly, and spraying down into the intake elbow? It will likely kick back at you as it is a closed end tube, and can accept only so much liquid/vapor before it must come back, so squirt and then let the throttle go closed immediately before cranking.
tom

[micscience]

NO start solved!

It was the new CDI I bought from Amazon. Every time I checked for spark with the new CDI it showed plenty of spark which threw me off I assumed the spark was fine. Even today before I replaced the new CDI with an older version is shows plenty of spark but it would not start the scooter the timing on the CDI was bad as the voltage spikes from stator went through it some how. The symptom was a big sounding back fire every 5 to 10 seconds.

Immediately the scooter started once I installed the older one. I also remember I installed the new CDI the same time I cleaned out the carburetor.

Something that needs to be said about these chinese scooters. Everyone says they are easy to work on but I don't find that to be necessarily true. The design is simple but you cannot rely on anything on the scooter to work right unlike their counterparts such as Japanese and Italian scooters. If I'm working on a yamaha 125 and I buy a new CDI for that scooter best believe that new CDI is going to work. I have worked on many vehicles and I could always rely on those new parts. Only had one instance where a new part was bad for a Chrysler timing chain tensioner and I believe the part was messed with by the previous person who purchased it he later returned it back to the Auto Zone. Usually quality control does a good job on more professional manufacturers unlike these cheap Chinese parts. Just my 2 cents thanks for your help guys. I'm glad I can always come here and ask for help and get a different perspective. Later...

[ratdog]

Hate to mention this,... no IDont, ... but I have mentioned in any number of my posts to avoid the so called “preformance” after market CDIs. While I have a couple ( red bike and black bike), the ones I have cost about $200 each and let you program the amount of advance at what RPM you want it. The “ preformance “ CDI I have tried leave the ignition at full advance all the time. That often makes the bike very hard starting. I have a (discard) pail full of them in my garage.

[micscience]

Well I avoid them as well because they are usually not put together well and from what I have learned you get harder starting in the winter months or the colder environment probably due to the poor construction. I would not spend $200 on a CDI What kind of gains do you get from that? anything noticeable?

[GrumpyUnk]

The costly 'tunable' CDI systems enable setting the spark timing differently at different rpms. You may want slower(RE-word-people-don;t-like) timing for easier startup, somewhat advanced timing as you accelerate, and even more advanced timing for cruise. I do not know the details so take with a grain of salt. I do know that RE-T'd timing will cause higher fuel consumption, higher engine temperature, and lower power in car/truck engines.(even diesel injector timing affects the previous) The CDIs provided offer fixed timing, much like a lawnmower engine, spark happens THEN. It does not change with rpm or throttle. Two-stroke outboard engines fiddle with the timing as the throttle is advanced. Remove the cover from one, and watch the magneto plate(on older ones anyway) rotates as the throttle is twisted to wide open. Throttle & timing are linked.
So the CDI can be adjusted, and costs a pretty penny, and is really useful to get that last bit of power. You can perhaps do better by elongating the mounting holes on the 'trigger' coil down by the flywheel. You can advance the timing somewhat as you see fit(within limits) for more power and economy. YMMV.
tom