my engine quits after like 15-30 minutes of running

James912

James912

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my engine quits after like 15-30 minutes of running. itll start again after like 15 minutes sometimes.i took apart the carb and nothing was blocked. any ideas. i have a 2 stroke slant head 44 t sprocket, everything else is stock. When it does start again i have to baby it till it powers up. i never even give it 1/2 throttle. i stay at low speed like the instructions say. i dont know whats wrong.
 
I think the choke nute needs to be tightened. Cuz all the vibration makes the lever go all the way down. Which is why it quits....maybe. But It runs better with the choke all the way down. I let u know if what happens when I do it tomorrow(saturday).
 
Check your electrical. not common for solder joints to fail on the wires going to the magneto and you may have a bad electrical connect at solder joints that gets worse with expansion from heat. magneto may also be bad when it gets warmed up. check electrical connectors....the stock ones are awful and solder and shrink wrap is your best bet or better fitting plugs.

worst case, you may be running to lean and the 20-30 minutes of riding is enough to cause your engine to overheat and then runs again when it coolsdown. please pull your spark plug and share a pic of what it looks like.
 
Will do, I've also been wondering if ive been runnin' lean, i just forget to check the plug every time. I will deff check the plug and share a pic. It'll be first thing 2maro. :) I really hope this is my problem.
 
lol. Ive done dangerous things with gasoline too. lol I think the engine is overheating. The cdi isn't getting hot, and the magneto only gets a little warm but thats because the engine gets overly hot. and the heat spreads after a few minutes. i know engines are supposed to get hot, but I think its shutting itself off cuz its getting too hot. After it shuts off, i let it sit under my breezeway and after it cools off and its cool to the touch, i can ride it agian...for another 15 minutes and it shuts off again. I even moved the c-clip up a notch from the stock position and it didn't help. Could it not be letting out enough exaust and therefore it overheats? The exhaust port on the engine is rectangular with curved corners, and my stock muffler's inlet is circular.
 
no, exhaust port restriction due to size difference between the port and muffler intake won't do that. which way did you move the c-clip on your needle
 
I am using a paper inline filter. Lastnight, it started and bogged down and died as usual. Nothing I tried would keep it going. Then It wouldn't start again. It caught again and when i gave it alittle gas, it died immidiately.
 
heres my plug
file.php

After i took this pic i moved the e-clip down one notch from the middle stock notch and it still looked the same.
I haven't seen any leaks.
I've checked all bolts.
Still overheats and dies.
 
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I once a had a similar problem with a two stroke snow machine. It was in the fuel line, There was a piece of garbaged lodged in the line and it acted like a valve, give it to much gas and it rotated and cut off fuel, kill the engine and let it set and it would open up again and run fine, it was a pain to trouble shoot, because it acted like a carb issue. I would check your line near the tank, or the tank where it enters the petcock. The problem is probably before the fuel filter.
 
I'll try that tonight when i get home from work. But that shouldn't cause it to overheat though, it would starve and shut off before it would overheat.
 
Yes it would starve and shutoff, the "cool down" time may be the fuel working its way through the garbage and putting enough fuel in the carb and lines to let it run for a bit. With the engine running you are pulling a vacuum that is sucking the fuel in to the engine, when it finally dies there may not be enough fuel on the engine side of the clogged line to start the engine and with the engine not running it may not be pulling enough vacuum until the carb and lines refill.

Now keep in mind I could be way off and totally full of poo, but clogged lines are not unheard of on these thing, and the right kind of obstruction can do some funny things. Plus plugged lines is the easiest and cheapest thing to fix/check first.
 
But my lines aren't clogged. My filter is stock and doesn't hinder the flow of fuel to the carb, and ill inspect my petcock to be sure its not getting clogged. I have seen air bubbles in the fuel line. Is that normal?
 
If it is clogged it will be in or near the petcock usually. If you have air in the lines after running turning on the fuel and running for a bit, that might be a problem. Aside from a small bubble that may from in the filter, air should not be in the lines once the engine is running, if you are getting bubbles, then the line is obstructed and the vacuum from the engine is pulling air through one of one of your fuel line connections, or you ar out of gas.

Like I said I am just guessing, but double check the pet cock before buying a new cdi or magneto.
 
1. Run the motor until it dies.
2. Turn off the petcock, and remove the bowl from the carb. Check the level of the fuel in the bowl, it should be full. -if it isn't full see (fuel)
3. Check the jet to make sure it didn't fall into the bowl. -if so just screw the jet back in

(Fuel) fuel supply issue:
- vacuum problem in the gas tank, that kept happening to me, try removing the gas cap and priming the carb with WOT until gas overflows from the valve, try to start it up, if that fixes the problem then drill a very small hole in the top of the gas cap. If you want to ride in the rain simply glue/epoxy a pop bottle cap on top of the hole and drill a small hole in the side of that.
- make sure that the gas level is above all points of the gas line and the carb

This is all I can think of at the moment, hopefully it helps.
 
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IF it's a pluged air vent in the fuel cap, a quick loosening of the cap when the engine is dying will make it staighten out and run.
If you decide to drill a vent, it need not be through the top surface of the cap. You can drill the underside of the cap in the area around the very edge - the part that will be OUTSIDE of the rubber gasket when it is installed on the tank. I just modified a new cap that had the problem and it worked great.
 
I fixed my bike. The reason it would stop working after 15 minutes is the gas cap does not have a top vent, there are only air holes on the bottom of it, below the rubber seal. I drilled a hole in the top and she keeps running. If u want to ride in the rain, just get a waterbottle cap and hot glue it to the gas cap, over the hole and drill a hole in the side of that.
 
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