Author Topic: my moped doesn't start. is it a weak spark?  (Read 4367 times)

csor.zola

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my moped doesn't start. is it a weak spark?
« on: November 27, 2014, 06:55:38 PM »
Hi there,

My moped won't start. My guess is that the spark is too weak. But i made a video and shared on youtube. What do you think about that? Is it weak? But compering to my working moped it's definitley weaker. But that one is a different model. I am not sure. The battery brand new fully charged. I have checked and cleaned the ground cable from the battery. The carb brand new done zero km. And the petrol gets there. Any idea?

zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #1 on: November 27, 2014, 10:15:25 PM »
The link comes up as a "private video"

Three things are needed to start/run... Fuel/compression/spark. They all have to happen at the right time, and in the correct amounts.
"Weak" spark is very rarely an issue if the rest is in order. Spark of any sort can ignite fuel/air IF they are correct, and have good compression.

Start from the beginning... Why did you replace the Carb. have you done a compression test? Have you double checked the Kill Switch?
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #2 on: November 27, 2014, 11:39:20 PM »
Sorry, now you can watch it. But it's not very good quality. On my phone it's better but in reality it's still hard to see the spark. I gonna attach a picture.
So this bike costed me £50 but I had to replace couple of things like battery, spark plug and carburetor. But it still doesn't want to start. Compression OK.
Where is the kill switch? Do I have one

zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #3 on: November 28, 2014, 12:36:17 AM »
If your bike has a kill switch, it will be a toggle switch on the trhottle side. It is a large switch that you can reach w/ your thumb when gripping the throttle

Do the compression test to be sure... Ok means very little there.  IF it is over 102 psi  (throttle wide open) Adjust the valves. .4mm cold, or .004".

Check thru the air box too. I have found mouse nests in bikes that have sat for awhile.

See where these things get you, and post back. The spark you have should start the bike.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #4 on: November 28, 2014, 09:40:59 AM »
Why is it called kill switch? This button starts the engine, doesn't stop it.
About the compression. I don't know what you mean to test it. When I try to kick start it I can feel the resistance.
Some additional information.
My friend asked me to clean the carb of this bike. In summer. It was running and started first time but during acceleration started stalling. So, I took it down to my garage, cleaned the carb put it back and the bike didn't start at all. But the carb was fine. Later when I bought this bike swaped its carb and used it in my bike with no problem. And then I replaced it with a new one.
I gonna check the valve but it's strange. Before I took the carb off was running and then finish.

zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #5 on: November 28, 2014, 11:43:29 PM »
There are a lot of maybe's... A compression test is this, 

The gauge kit is about 40 bucks or Advance auto rents them for 10-15 per day.

BUT since it was running I would look CLOSELY at the rubber carb mount (intake manifold)  they ALL crack. Your installing a new carb almost guarantees it has cracked. The best thing to do is take off the manifold, and inspect the Bake'o'lite insulator underneath it. That piece also cracks, and allows air leaks. You can buy two new o rings for under a dolar to replace the originals at Ace Hardware.
This vid shows the parts... 
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #6 on: November 29, 2014, 07:00:42 PM »
Thanks

I will back soon hopefully with some good news

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #7 on: December 01, 2014, 06:54:20 PM »
Good news. My scooter is running. What was the problem? I am not sure. I took off everything cleaned it and put it back and it starts now first kick. If I must point out what was wrong I would say probably the ground. Now the spark a bit better.
But I still got one question. I had to change the starter motor and it turned out that it has additional problem with starter clutch as well. You can hear as the starter is spinning but it does not have contact with the starter clutch. Where can I find it? Is it behind the flywheel or I will have to open the engine case completely?
« Last Edit: December 01, 2014, 07:04:10 PM by csor.zola »

zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #8 on: December 01, 2014, 10:51:41 PM »
That's a simple part, and it is just behind the CVT cover. You can pull it out without taking off the variator or belt. Just fiddle w/ it till it comes out.

Use some PB Blaster to spray it down, and free it up. Sometimes you DO need to replace it but not often. They usually just jam up from belt dust. Put a SMALL dab of grease on each end, and put it back in.

Watch the engine case side. There is a small washer that usually falls off. It goes between the bendix (starter gear), and the case.
« Last Edit: December 04, 2014, 10:26:00 PM by zombie »
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #9 on: December 03, 2014, 09:46:14 PM »
Thanks. But as it turned out it has much more severe problem than the starter clutch. I tried to change the oil and when I unscrewed that bolt lots of small metal pieces came out along with the oil. It's definitely from some bearings. Dear me. I intended to repair this scooter  sell it and make some profit. No chance. But I know what I gonna do now. I gonna keep it and build up a tuning bike as a project with a big 180cc engine.

zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #10 on: December 03, 2014, 10:55:03 PM »
i GET IT A LITTLE BIT.
All the parts to rebuild are under 199. USD

If the entire engine is toast....  450.00

Sorry I'm Hugh at the moment.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

csor.zola

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Re: my moped doesn't start. is it a weak spark?
« Reply #11 on: December 04, 2014, 06:19:50 PM »
That is my plan. But this scooter has no much value here in London. I have one question left. Do you know where is that pieces are from? I gonna attach a picture. I hope is only just a bearing and the engine case has no damage.
What do you reckon?

CROSSBOLT

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Re: my moped doesn't start. is it a weak spark?
« Reply #12 on: December 04, 2014, 08:38:15 PM »
Looks rollers out of a roller bearing except for that larger rectangular chunk.

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zombie

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Re: my moped doesn't start. is it a weak spark?
« Reply #13 on: December 04, 2014, 10:32:22 PM »
I think it is the wrist pin bearing, and a piece of the cage from them.
I don't understand how they worked their way out tho. The only way to be sure is to remove the cylinder, and then the piston.

Get yourself a gasket set first... Head gasket/Cylinder base gasket/"O" rings for the intake manifold/Exhaust gasket.

There are a ton of GY 6 rebuild videos on YouTube. Watch a few to get the idea...
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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