installed BBK, No start By lacrosseguy (Read 1,196 times)

[lacrosseguy]

after my piston broke i just ordered a bbk off of amazon for my basic gy6 (70cc).the scooter was not starting or making noise from before. and i installed the kit and readjusted the valves last night. when i got home from work today i finished installing everything else back on. but now all it does is crank and wont start. i was thinking a possible battery problem ? i have a battery charger, but i have no clue if it compares or fixes a 7 month old battery, but i have almost no cash to drain into this anymore:/ i can have video or pictures of anything you want by request. here was my previous page .http://scooterdoc.proboards.com/index.cgi?board=150cc&action=display&thread=7893

Thank you all for helping me,

[Alleyoop]

Have you checked for spark holding the spark plug on the motor NOT the frame.Check your ground wire from the motor to the frame. Also check for compression, if you do not have a compression gauge use your finger. Hold it nice and snug in the hold and crank it. If it BLOWs your finger off the hole it has descent compression to run. If you just feel some pressure on your finger then not enough compression for the motor to run. Also check your killswitch make sure it is on the run position, you can also take the TOP BLACK/WHITE wire on the 2 PLUG cdi which is the killwire to make sure the killswitch on the handlebare is not stuck grounding the CDI.
Alleyoop

[lacrosseguy]

i did the compression test last night and it was not blowing it off, but it had some pressure. what are possibilities of low compression if i just swapped my head,piston,piston rings, and crankshaft

[lacrosseguy]

I just did the the compression and spark test again.
i had my brother put his finger over it and it blew his off 3 times.

i did the spark and it had none. so im running to autozone to get a plug right now !

[Alleyoop]

Great about the compression, have you checked the ground from frame to motor?
If the motor was running before the build think of the parts and or what you changed or check for bad wire connections.

Well you know the spark is created by the following:
0. Bad Spark plug (BUT VERY RARELY HAPPENS THAT THE SPARK PLUG IS BROKE INSIDE).
1. Boot Cap, inside the contacts are broken.
2. Boot Cap not making good contact with the wire inside (THE BOOT CAP SCREWS ONTO THE WIRE).
3. The WIRE is not making good contact with the COIL (THE COIL SCREWS ONTO THE WIRE).
4. The WIRES connecting to the COIL are loose or broke or burnt.
5. THE COIL IS BAD.
6. THE CDI IS BAD.
7. THE PICKUP COIL is BAD.
8. THE STATOR IS BAD.
Alleyoop

[lacrosseguy]

i had replaced the coil and cdi before with the orange performance ones. if that matters at all.

[Kaveman]

It may . If you still have your old cdi and coil try them first to see if you get spark.If you do then put one of the new ones on. you will know its either the cdi and or coil .
willc.

[lacrosseguy]

heres a vid of showing around the engine and me trying to start it.

[lacrosseguy]

and @alley it was not running before the build..

[Alleyoop]

What was the problem before the build that it was not running.

Did you set the valves to .004 intake and .004 exhaust or .005 exhaust?
Have you checked the timing on it. Sprocket Cam the two littl holes even with the head and the CASE POINTER pointing to about the FIRST LINE BEFORE THE "T" mark on the FLYWHEEL?
Alleyoop

[dippy51]

Anytime i had a strange electrical problem, i would start the vehicle up in the dark. Any arcing becomes visible. I had a slight miss in my '65 Ford truck once after working on it, using this procedure i discovered the spark plug back by the firewall had a hairline crack in the ceramic, not very visible but the dim arc light helped me to find the problem. Now i stand on something for a more comfortable position to install that back plug so i won't crack another one.

[lacrosseguy]

@alley i didnt come to a solid conclusion. but here are the previous threads you helped me with i got the low compression conclusion. so i installed a bbk with a new piston and rings, cylinder and head. along with a camshaft. i can link you if it matters, but i set my valves to .003. i can set them to .004 if it makes a difference. scooterdoc.proboards.com/index.cgi?action=display&board=150cc&thread=7893&page=1
scooterdoc.proboards.com/index.cgi?action=display&board=150cc&thread=7091&page=3#55519

[lacrosseguy]

my timing was just a bit off so i readjusted it and redid my valves. i had the top set really loose so that could have been a problem. i tried starting her up but i killed the battery so its on the charger now and ill post results in the morning.

[Alleyoop]

No you can leave them at .003 that is enough for it to start or at least fire.

Have you checked your timing?
Alleyoop

[lacrosseguy]

yes, my timing was about a chainlink off so i took it off and fixed it