tgb r50x starting issue By tominbmore (Read 13,584 times)

[tominbmore]

Apr 5, 2015 22:36:51 GMT -6 Guitarman said:

Sounds like no spark.

Check the engine ground. I'd almost bet it's loose or not even connected.
The engine MUST be connected to ground. The frame ground is not good enough.

I'm a noob. :/  How do I check an engine ground?  How do I tell whether it is loose/not connected/AOK?

I appreciate your advice, man.

[cyborg]

If you look over the engine there should be a pretty fat black wire anchored to the engine directly to the frame ,,,, if it worked loose you will have a no spark situation

[tominbmore]

Thank you. will do! Could you explain, pretending I'm a 10-year-old, what the "ground" does in the overall electrical system? I've come across it a lot, but still not quite grasping exactly what function it serves.

Tx!

[cyborg]

It's the return of the 12volts back to the battery,,, if you notice things like the starter and other parts only have one wire going into it,,, that's because the case of the part is grounded to whatever it's bolted to,,, it's like your car,, the whole body is the return "wire" back to the battery to complete the circuit

[Alleyoop]

Here is your CARB I have labled the TWO IMPORTANT SCREWS ON YOUR CARB.
See the AIR RATIO SCREW, Turn that 1/2 turn clockwise and see if it wants to start. By doing that we are cutting off some air and allowing more fuel to be sucked into the motor.
Alleyoop

[tominbmore]

Hey guys,

So I checked the wires to see if a big fat one had come off of the engine and lost its "ground." But no wires have come off the engine or frame as far as I'm concerned. In fact, just like before, there are still many different bundled wires secured against the side of the scooter frame heading from front to back. There are bundled wires coming from the stator abd going to abd from the battery, for example, but they've always been that way.

Alleyoop I followed your advice with the fuel ratio screw, turning it a full half turn, then a little more. But the result was the same when starting via ignition and via kick start. No luck.

As for the spark plug, I opened the ratchet set I got from amazon but discovered that the bolt securing my plug, like all things on this TGB scooter, is DIFFERENT from the norm. So the socket plus extension wouldn't was too skinny. See photo here:




I checked the sockets and found that the 13/16 fit the very-wide bolt. But of course that wasn't compatible with the spark plug socket extension, so I could only try to attach the 13/16 on its own. This created a separate problem bc the exposed part of the plug was too long for the 13/16 socket to reach the bolt. See photo here:



So I suppose I could try to remove the casing aroubd the engine there? Or might thry hsve a 13/16 socket thar will fit my spark plug extension? Advice is welcome here. This company is making it way too hard for me to do something most scooter owners can do easily.

Tx!

[cyborg]

You just need to get the large spark plug socket

[tominbmore]

Ok awesome tx!

[tominbmore]

Hey all!
Finally got the right socket extension abd got the plug out. I'm gonna test for spark next.

In meantime here's a few looks at my plug. I don't know what's good or bad and I don't have the doohickey to measure mm gap.

Care to tell me what you think?

[Alleyoop]

OUCH!! Your plug is fouled unfortunately it is OIL FOULED when means you probably have bad rings.
So since you know have the plug out lets check the compression on the motor.

1. Stick your finger in the spark plug hole and hold it nice and snuge.(don't worry nothing will happen to your finger).
2. Then HOLD THE THROTTLE WIDE OPEN AND CRANK THE MOTOR LIKE TRYING TO START IT.
A. If it lifts your finger off the hole it has descent compression.
B. If you just feel some pressure on your finger then the motor is low on compression.

Now check for Spark, First clean the plug, get a old toothbrush and clean it.
Then stick it in the BOOT CAP and hold the metal part against the motor and crank it and see if it is sparking.
Alleyoop

[tominbmore]

Also I've judt done a test following videos online. What I saw was a very thin spark not quite sure what color but thrre was a hint of blue in there. This very thin spark might be the norm but my hunch is this spark is weak. I'm not in dark garage bUT I'm outside in the shade and with my head and hoodie blocking indirect light.

Also,it seems like every other time I crank the engine I get no spark at all. Based on the pics above, my not expert guess is the plug is all gummed up and blocking a good spark.

Video coming soon.

I've bought plug replacement and will test it as a control test.

[tominbmore]

Ok alleyoop will do! !

[tominbmore]

Alleyoop,

Compression seems fine. Wide open throttke plus ignition crank = pushing finger out of the slot. Specifically, the finger was kinda bouncing off the edge of the hole. Good air pushing out, and I really had to make an effort to keep my finger snug like it started.
But I'm not convinced... am I looking for like REALLY strong air force like a nail gun etc.?



Sound ok?

Plug cleaned and I'll check for spark one more time.

Btw whst does "bad rings" mean?

Tx for your help!!

[Alleyoop]

Ok, if you held your finger in the hold nice and snug and when cranking it lifted the finger out of the hole then compression is descent, at least enough for the motor to run.

Well bad rings mean the motor is loosing compression and allowing oil to get past the rings and up into the chamber where the fuel is ignited and creating an explosion and that is why you see OIL on the plug and threads.

[Guitarman]

Ohoooo... Bad rings for sure. How old is this motor? Do you know how to change the oil?
I bet you have little metal bits in it. Not good.

Sorry, I don't get to the forum as much as I'd like, so my responses will be erratic. But you have Alley and cyborg helping, and that's two of the 4 Musketeers. So you are in good hands.

The piston that goes up and down inside the engine has these thin metal rings around it to keep oil on one side and the gas/air explosion on the other side. When your rings go bad, oil starts leaking into the compression chamber and it messes everything up.

Clean your plug with a toothbrush and a tiny bit of gas or carb cleaner. Then test the spark on both plugs by connecting the wire to it then cranking the engine as you hold the plug on THE ENGINE BLOCK ONLY to see what kind of spark you get. Best to do it in the garage so you can see it better, but you should still see a fat blue spark pretty easily.

If both plugs have the same kind and size of spark, then the plug is not your problem, but it could be the plug is not getting enough Juice to fire. Might need to replace the CDI.

See if you can find a fat wire bolted to the engine block and show us a picture.