No Spark on a Hi Bird GY250

[Hmanfl]

(05/23)
I finished putting together my Hi Bird GY250 on Friday.

I took the bike for a ride around town and had about 26 miles on it.
I was doing about 30 mph and it just died on me, engine just stopped.
At first I thought it was low on gas, switched to reserve, but it would not restart.
Started checking and found that it had no spark to the plug.
Still had juice to rest of bike just no spark.
Had tools with me and I pulled everything off but the gas tank and
checked all the wire connections, they were good.
Pulled spark plug and held it against the engine and found that
I had no spark when kick-starting it.
Had to Trailer it home.

(05/25)
I took every thing off, checked each wire connection, used wire ties to lock
all connections together. Took apart kill switch, looked ok. Put a volt meter
on the two lines supplying the coil, no voltage there.
Tried a different spark plug, still no spark.
Checked the white connectors to the CDI, they look ok.
Battery is at 12.82 volts.


Any Ideas?

Any tips on steps to trouble shoot the Ignition System?

Thanks for the Help !!

[Komoto250cc]

Make sure you check the fuel line running from the shut off to the carberetor. The original hose is cheap and kinks easy. I replaced mine with some clear, rigid hose. It costs a dollar for a foot.

[TeamCheap]

I dont know..Hmmm.....have you taken the chain cover off the engine and looked at the wires coming up out of the engine to see if they somehow got damaged ?

If you got no power going to the coil wires then thats what you need to back track I would think.

Does that bike have a safety switch on the kick stand ?

I'm just throwing stuff out there.

[justinkr58]

no safety switch on the kick.. but maybe the cdi went out?

[DesertDog]

cdi's do go out ?

coil's go out ?

did u check to see if the ground wire is loose, the one to the engine (green) bolts to one of the side case bolts, ?

but do check the chain cover area like teamcheap ad vised, the chain could-a snaged one of the wires and oops no power !

[TeamCheap]

He said he has no power going to the coil so he coil itself may still be ok.

or just the cover itself could have been pinching a wire down there.

I would also double check the key switch and kill switch.

[Hmanfl]

Bike Has Gas, drained some from Carb just to be sure.

No safty switch on kick stand.

Ground wire looks good, tight, under seat above carb.

Checked kill switch, took apart, rocker type switch, two copper pin type
contacts, both look clean, switch is tight. Kill switch wires are connected to
correct plug behind head light.

To trace the wires from the coil I would have to unwrap the wiring
harness and I don't want to do that yet. Should not be any connectors
between the CDI and the coil. Coil has 1 Black and 1 Green/Yellow
wires. CDI has same two wires.

I will pull the chain cover off and check the wires in that area.


Thanks

[liverchip]

Possible CDI or coil problem.

[liverchip]

I suppose you could use a dwell meter to verify proper duration/presence if charge voltage to the coil.

[Hmanfl]

I pulled the front cover by the chain off and looked the wires over,
they looked good, undamaged.
Bought a new spark plug and gave it a try, nothing.
I mean it won't even shock me and it should.
With no power to the coil, I'm thinking bad CDI.
I'm going to give Tim at Vbikes.us all call on Tuesday and see what he
thinks I should do.

I don't know what else to try, unless one of you has a Gy250 and a volt
meter and wants to spend an hour on the phone with me verifying voltages
on each of the CDI wires...I'll save that for a last resort.

Thanks for the Help

[culcune]

I'm going to give Tim at Vbikes.us all call on Tuesday and see what he
thinks I should do.


It should still be under warranty. Don't do anything more, IMO. Wait to see what Vbikes say.

[Hmanfl]

Have you guy seen this before, is it on this site as a sticky ??

http://www.rnrfabrication.com/wiring.htm

scroll down till you see

Lifan 125cc / 150cc /200cc Electric Start Engines

Looks like a good wiring diagram for our bikes

[justinkr58]

any luck with the bike,

[liverchip]

Have you guy seen this before, is it on this site as a sticky ??

http://www.rnrfabrication.com/wiring.htm

scroll down till you see

Lifan 125cc / 150cc /200cc Electric Start Engines

Looks like a good wiring diagram for our bikes

Wow, nice find!

[Hmanfl]

I am back up and running !!!

Big Thanks to Bruce at EJCycles for all the trouble shooting tips.

It was a Bad CDI.

I found one EBay for 15.00 shipped, plugged it in and she cranked right up.

I'm still going to send the old one back to Tim at VBikes.us , but this way I'll have a spare.

Here are the steps I used to trouble shoot the No Spark Problem.

Found a Lifan wiring Diagram Here
http://www.rnrfabrication.com/wiring.htm
Scroll down till you see
Lifan 125cc / 150cc /200cc Electric Start Engines


1. Checked all wiring Connections, wire-tied them all together.
2. Pulled Spark Plug and held against Engine to check for spark.
3. Tried New or Different Spark Plug.
4. Pulled Front Sprocket Cover off and checked the wires coming
out of the magneto for damage.

Behind the Head Light
5. Un-plugged the Kill switch ( This grounds out the CDI when its on )
(This eliminated the Kill switch)
6. Un-Plugged the Ignition Switch, then used short pieces of insulated wire to
Hot wire the bike right at the white plug. I used the wiring Diagram to see
which wires completed the circuit. In my case it was like this.
Four Wire Plug, Upper Left to Lower Right and Upper Right to Lower Left.
(This eliminated the Ignition Switch)

Under the Seat/Tank
7. Removed Spark Plug. Used a Multi-meter to Test the Following things
a. The spark plug cap had continuity.
b. The coil had continuity.
c. Each of the two wire running from the coil to the CDI had continuity.
(This eliminated the coil mostly, could still be a weak failing coil)
8. CDI, Could not check the CDI because I didn't know what values a
Normal working CDI would have.
9. Checked wires coming from Magneto that go to the CDI (6 wires)
(Used the wiring diagram to understand the grouping of the wires)
a. 2 of them make up the timing pulse circuit, I got around 3vdc on this.
b. 2 of them are the AC circuit that charge up the high voltage capacitor in the CDI.
I got around 46VAC on this circuit, also got a nice jolt too !!
c. I think the last 2 wires power the CDI, I got 12VDC on this.

Here is info on how the CDI works, found it on Yahoo

The basic principle

Most of typical ignition system used in cars are inductive ignition system,
which is solely relying on the electric inductance at the coil to produce
high-voltage electricity to the spark plugs. In a CDI system, the system
charges a capacitor by default, and during the ignition point the system
stops charging the capacitor, allowing the capacitor to discharge its output
to the final coil before reaching the spark plug.

A typical CDI module may consist of a small transformer, a charging circuit,
a triggering circuit and a main capacitor. Firstly, the system voltage is raised
up to 400 V by a transformer inside the CDI module. Then, the electric
current flows to the charging circuit and charges the capacitor.
The rectifier inside the charging circuit prevents capacitor
discharge before the ignition point.

When the triggering circuit receives triggering signals from triggering devices
such as Hall effect sensor or pulse generator during the ignition point, the
triggering circuit stops the operation of the charging circuit, allowing the
capacitor to discharge its output rapidly to the ignition coil. The rapid capacitor
discharge then produces a very high voltage at about 40 kV to be fired at the
spark plug. When there's no triggering signal, the charging circuit is re-connected
to charge back the capacitor.

To summarize what I found with my bike:

I had juice going into the CDI but not coming out.
I eliminated the easy stuff first.
What was left was the harder more expensive fixes.
I felt that it was the CDI and took a chance, it was cheap and easy to replace.
If it turned out not to be the CDI, I would have tried the Coil Next and the
Magneto Last. I would also have tried disconnecting all other electrical connections
on the bike to eliminate any possible shorts.


I also installed one of these from Dennis Kirk

120 Degree Flashing Spark Plug Cap
http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=Main&catId=&productId=p20294&leafCatId=&mmyId=

It's not the best quality, but I can see that I have spark quickly.

And the Down time was not a total waste,
I learned allot about my bike, Installed a Uni-pod Air filter, relocated the
battery under the seat, put on a Action pack (Rubbermaid - Wal-Mart) for
storage, put in the 44w head light bulb, and got together a decent tool kit.

I hope this was a one time problem and not something that reoccurs.
I just want to go for a ride, feel the wind.

Thanks

[IronFist]

Best info, best fix, best write up I've seen in a long while. :D

I like the caps that light up, great idea. Electrical tape would cover the flash if you didn't want to see it all the time. I have cheap see through fuel filters. I don't know how well they filter, but I like that I can see if I have correct fuel flow. Sort of the same with the caps, just a cheap way of telling if there is a problem.

I'm sure Kato will look at the wiring diagram and sticky post it.

Glad you got the chance to do the other bits as well. The only down side is that you just told thousands of people how to hotwire your bike :? It's up to you but, if you want to, just go back and edit that out before too many people read it. Happy you're back up and running.

[zundapp2]

Where did you buy the CDI?

[liverchip]

Great job!

[Hmanfl]

Where did you buy the CDI?

On eBay

Here

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=015&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=250251497337&rd=1

[zundapp2]

Hmanfl:

Many thanks for the info.

[Dragon]

So this is why there is a redundant CDI on the GY-7.