Moped will spark after 5 min of riding

Casey Lacourse /

Hey everyone. I recently got a moped I found in my grandfathers shed. It had about 7k miles on it but it looks like it is in almost perfect condition. Since I got it, I have had to put it two bran new tires and tubes, a starter/drive v-belt. A new Drive chain, and I had to clean it up and everything.

So this is the problem, The engine will start up fine cold, I can ride it for about 10 minutes, then If I come to a stop and let it idle it will die. Then when I try to start it back up again, it will not spark. ( I have not verified this but I have been around these 2-Stroke engines and I can tell buy the sound and the way it feels that it is not sparking. I have taken apart the carb when I thought it was a carb problem and I know it is getting enough gas.

I can ride it for as long as I want, (I have only gone about a max of 30 min) but I just have to keep it revving when I stop.

I have also found that after the engine warms up, about 3-5 minues of riding there is almost no performance. The engine bogs down and can barely make it up a very small incline. The engine also max's out at about 23mph where I know that I can get it up to about 32-35 when I first start it up. So this leads me to think that it is not fireing all of the time...

So I am almost certian it is an electrical problem. I have not even looked into taking off the flywheel to get to the points and condenser because I want to know if there are any tricks to do so. I have found some coils and consenser for this online on ebay for about 40$ and I was looking into getting that. But I want to know if anyone else has had this problem and there may be a cheaper or easier fix

Thanks in advance!

Re: Moped will spark after 5 min of riding

ಠ_ಠ Jon Folks ಠ_ಠ /

Sounds like a bad condensor to me. I would also clean the points first for sure. Check fred's guide.

Re: Moped will spark after 5 min of riding

Casey Lacourse /

Where can I find this guide?

Re: Moped will spark after 5 min of riding

Timmy Southpark /

Its in this sites resources page. go to articles, but heres the link....

http://mopedarmy.com/resources/articles/fredsguide/

Re: Moped will spark after 5 min of riding

I'd say it's the condenser also. I had the same thing happen many times. The condenser always fixed it.

Re: Moped will spark after 5 min of riding

See Ya Moped Army /

First, I would test to see if it actually has spark or not. Unless you have Xray vision, I don't understand how you can listen and tell it has no spark. If it doesn't have spark, I would clean and gap the points before replacing anything. If that doesn't get spark, then the condensor would be the most likely culprit.

Re: Moped will spark after 5 min of riding

may be a fouled spark plug, may be the condensor, make sure you have a good spark.

Re: Moped will spark after 5 min of riding

Don Pflueger /

the condensor may be bad, but if it still runs when he revs it, but wont idle, its losing crankcase pressure and/or vacuum. a bad condensor would act up thru all stages of idle. but a bad base gasket or crankseal would affect idle since the engine is running at a slow rate and cannot produce the vacuum and pressure needed to maintain idle.

Re: Moped will spark after 5 min of riding

Don Pflueger /

i agree here. look before you replace anything. i doubt it is the condensor.

Re: Moped will spark after 5 min of riding

Re: Moped will spark after 5 min of riding

Jason Luther /

when in doubt, buy a new $2 spark plug.

Re: Moped will spark after 5 min of riding

Casey Lacourse /

I will go for the new spark plug this weekend since I have a long weekend off from school. If that isnt the problem, I will buy a NOS NOVE ignition off of ebay. It comes with the whole coil, points and condenser never been used.

Thanks a lot.

Any advice on taking off the flywheel, It looks like the previous owner had a great time trying to fix it, what kind of thread is on this flywheel, I have some pullers, should I used thoes? Are there any tricks to doing this?

Re: Moped will spark after 5 min of riding

I agree with DonP...........an air inleakage may be the culprit.

You can't tell if it loses spark just bythe sound...trust me. A bad crankseal makes the engine seem like it's getting no spark OR fuel. don-ohio

Re: Moped will spark after 5 min of riding

it could also be a coil. I thought it was my condensor but turned out to be a coil with the same problem. and yes mine did not idle when it was warmed up, but did when it was cold.

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