Lexmoto 50cc electric start ... Part 2

Some of you will remember that my son’s 50cc moped is able to start using the kick-start, but not via the electric start.

The electric start seemingly powers up the start motor, and makes all the right noises - but there is ZERO current fed to the coil to create a spark.

In ‘Part 1’ we concluded that the likely culprit was the CDI … and have gone through two pairs of boots with the kick start, decided it was time to buy a new one …

£59 later, together with a new battery (all fully charged and settled as per requirements), new CDI and battery were installed weekend gone. Result - zip !

See Wiring Diagram.

I tested the cable (B/Y) from the CDI to the coil, and the earth to the coil (B/W) - all checks out.

I then checked the Starter relay - all seemingly good there.

I’ve then highlighted the wiring diagram to mark off the above checks and all cables / components I know work.

I’m thus left with the un-highlighted components and cables.

Before I go headlong into the bike with meter in hand next week (and get more moans of “why did you buy that f*cking bike?”) wondered if anyone had any ideas based upon the diagram and symptoms?

Attachments

PS. post ‘kick start’ start … she runs fine.

No matter what you do the questions of “why did you buy that fucking bike” will always keep coming :frowning:


No matter what you do the questions of "why did you buy that fucking bike" will always keep coming :( Serrisan

To which I respond … “because it was the only one suitable to the budget YOU set !!” … [blows raspberry] … )


No matter what you do the questions of "why did you buy that fucking bike" will always keep coming :( Serrisan

To which I respond … “because it was the only one suitable to the budget YOU set !!” … [blows raspberry] … )

IanWilliamson
i lost my version of the diagram

email me a new one

do you kick start it with the stand up and/or clutch lever pulled in?

I’ve tried with clutch in … no joy

Think I’ve tried the elec with stand up … but will do again tonight to make sure

I’m pondering if it’s a safety switch stopping you doing exactly that. which would manifest as sidestand sensor input to the CDI

Just to be clear. With the clutch lever held in, side stand up, centre stand, neutral gear selected and…

  1. Ignition on, kick starter and the engine fires up and runs as it should

  2. Ignition on, press starter button and a) The starter motor spins up. b) The engine turns over. c) The engine does not fire up and start.

Question - What happens if you press the starter button after you’ve fired up the engine by means of the kick starter? (I’m expecting the starter motor to spin up and the engine to cut out).

Right … just got my son at home to do the following:

Clutch in + Starter = no joy

Side Stand Up + Starter = no joy

Clutch in + Side Stand Up + Starter = no joy

Kick Start Bike + Starter = he tells me he can’t hear the starter motor (but the bike is loud) and the bike does NOT cut out.

To be sure, to be sure, to be sure, back to ignition on and  press starter button.

Does the starter motor spin up?

Does it turn the engine over?

Try this - Ignition on, press and hold starter button and kick start the engine at the same time. I’m expecting the engine to start.

> The electric start seemingly powers up the start motor, and makes all
the right noises - but there is ZERO current fed to the coil to create a
spark.

How are you testing this?

Also, what does ‘no joy’ mean?

Ian May have forgot to add the CDI’s used are unrestricted CDI’s

not OEM

my gut feeling is they haven’t been designed for electric starters & the signal for the pulse coil isn’t getting through


To be sure, to be sure, to be sure, back to ignition on and  press starter button.
Does the starter motor spin up? YES
Does it turn the engine over? YES, BUT NO IGNITION AS NO SPARK
Try this - Ignition on, press and hold starter button and kick start the engine at the same time. I'm expecting the engine to start. IGNITION ON, STARTER BUTTON DEPRESSED, KICK START - BIKE STARTS
National Treasure
See above in CAPITALS

Ian May have forgot to add the CDI's used are unrestricted CDI's
not OEM
my gut feeling is they haven't been designed for electric starters & the signal for the pulse coil isn't getting through
Wise
Correct - however I've spoken to two different suppliers and both have stated that the CDI should provide elec start

> The electric start seemingly powers up the start motor, and makes all the right noises - but there is ZERO current fed to the coil to create a spark.
How are you testing this?
Also, what does 'no joy' mean?
Big Red S
Spark Plug out and tested again engine - kick start produces spark, electric start does not

no joy = no start

no joy = no start

IanWilliamson
haha, yeah I guessed that. I assume from the above that 'no joy' means it spins the engine but never fires. 

Does it behave any differently if you jump start it? 

the other way to test is to make sure the bike is in neutral

& run a live wire direct to the starter from the battery  

that will bypass the relay & the CDI

Forgive me, but what would getting the starter spinning up do if there is no spark? 

Surely the question is why is there no spark … as everything else seems to ‘work’? or am I being too simplistic?