50cc taotao vip wont start - help By garysinthehouse (Read 981 times)

[garysinthehouse]

Here's the short story - I have 2 identical scoots.  Both ran fine, and one night after the midnight ride parked them in the garage. next morning about 6am the one I ride wont start. turns over fine. I checked the tank and there is fuel. There is spark and compression. just turns over. Starting fluid no help. Swapped plugs and carb from running scoot, and still no start.  Instead of buying compression tester, bought BBK so has new top end now still no start.

Before it died installed new variator, rollers clutch and belt.  ran a week with the new  parts which should not affect the starting anyway.  what am I missing??  this has to be something stupidly obvious I am missing.

I've read a ton of stuff, and nothing seems to work.  I've been messing with it for 3 weeks now 

PS - PAR system remove and vacuum plugged (before it died)

[Alleyoop]

Have you checked your killswitch also it may have one on the sidestand.

Are you sure you are getting spark, how are you testing for spark. Are you testing for spark on the motor holding it on the valve cover. Most folks check for spark on the frame but if the motor has a bad ground it will not fire when in the motor.

So crank the sucker over and then take the plug out and how is the plug WET OR DRY?

[garysinthehouse]

I have checked the kill switch, and brake switch (wont even turn over) so all good there. Spark checked holding plug to motor (valve cover bolt)  and the plug is not soaked but wettish after a few cranks. (I think should be wetter)

Timming was put back together with fly wheel at "T" and piston at top of stroke, cam gear "dots" at 9 -12 and 3 oclock

[Alleyoop]

Ok lets check your compression, if you do NOT have a compression gauge then use the old finger trick.
Take the plug out stick your finger in the hole hold it nice and snug then HOLD THE THROTTLE WIDE OPEN and crank it. IF it lifts your finger off the hole it has descent compression IF you just feel some pressure on the finger then it is low on compression.

So then CHECK the VALVE GAPS set them both to .003 inchs. It may be the valves are tight and your loosing compression.
Alleyoop

[garysinthehouse]

First THANK YOU for your help so far.

Second, I gave it the finger (more than once at this point) and it is sucking, not pushing, but I feel some air pressure from somewhere.   The battery is now dead from the attempts, so im going to give a charge and try again later and check valve again.  when installed they were set.

[jjoshua20213]

Check for a weak spark. You may have a bad cdi/spark plug. Have you changed the changed the carb?

[Alleyoop]

Well If no pushing then I would re-check your timing, sucking means the valves are close and the piston is going down.

[Alleyoop]

Well If no pushing only sucking then I would re-check the timing.

[tvnacman]

Aug 12, 2015 13:43:22 GMT -6 Alleyoop said:

Well If no pushing only sucking then I would re-check the timing.

2nd this

[garysinthehouse]

Well the verdict is in!    I checked for spark again, and was fine but when I went to check again the was none. Moving around the wires made it spark again...It was the coil. Varified by stealing the coil of the working scoot.lol oh well live and learn...I got a big bore kit out of it lol waiting for the new coil to come in the mail

[Alleyoop]

Great, glad it was an easy fix.
Alleyoop