no spark on pulse rythum By scooterdude (Read 766 times)

[scooterdude]

hi everyone ive been on here before but i have forgotten my login details so have re regestered i had just purchased a non running 2008 pulse rythum 50cc scooter dirt cheap so i can get my son back on the road at minimum outlay i know a little bit about these scooters as i have worked on gy6 engined scoots before
i have checked for the usual causes of these engines not running (exhaust valve not closing fully) and have reset tappets to correct settings now there is plenty of compression however there is no spark at the plug also when the ign is switched on the indicators horn and brake lights all work but the starter won't turn over when the button is pressed but it will turn over if you bridge the solinoid with a screwdriver i have also disconnected the black/white wire from the cdi to see if i get a spark but still no spark at plug could it be there is an immobileser issue thanks ken

[scooterdude]

ooppps just relized ive posted in the wrong section can someone please move it to the right section thanks

[alleyoop]

Since you unplugged the killwire from the CDI then that eliminates the CDI being grounded. So now it is testing time and to do that you have to have a Mult Meter.

There are a few things you can check, First make sure there is a ground wire from the motor to the frame.
Then check the Boot Cap sometimes if old the brass clips inside break and do not grab the Plug. Also the Boot cap itself make sure it is nice and tight on the COIL WIRE(the boot caps screw on into the wires inside the coil wire). Then check the connections on the coil itself make sure they are on nice and tight. Then after that you will need to check for Vac from the stator when you crank it(multi meter time). So at this point it could be the STATOR, PICK UP COIL, CDI, COIL, BOOT CAP, PLUG...
Alleyoop

[kensascona]

:DPROBLEM SOLVED after checking for ac from stator this proved ok so i swapped a cdi unit over from a working scoot i had and bingo we now have a spark i then brought a new performance cdi off ebay and got the engine running but even at full throttle it would only run at 1000 rpm cleaned out carb no improvement swap carb from running bike still no improvement so off came the valve cover to check valve clearences both were spot on on next step check cam timing but when flywheel was set at tdc cam sprocket was out of line reset cam timing and turn engine over by hand and valves were hitting piston WTF so reset cam timing back to normal and turned engine over with screwdriver in plug hole to find tdc and lo and behold timing mark on rotor was 90 degrees after tdc mark on casing so off came the cooling fan and bugger me the crank nut was finger tight off came the rotor and the woodruff key had sheered off 1 30p woodruff key later everything was set up and reassembled fuel turned on ign turned on and 2 kicks later VAROOM YEE HAR ENGINE NOW RUNS LIKE CLOCKWORK only thing is is slow to pull away from stand still but then again its only a 50cc 4 stroke ped might try fitting 2.7 g rollers in the variator as its got 4g rollers fitted as standard so lighter roller should keep it in lower gear longer so it can pull away quicker

[alleyoop]

2.7gram weights!! No bud with 4g weights that sucker should be screaming something else is wrong. Either low on compression or your off on the timing or the belt is climbing to fast up the variator. Do you have a tach on it, a tach will tell the whole story of the motor.

Get a video going on how it revs on the center stand and the rear wheel.
Alleyoop