Engine starts, then poops out on me

[(Ian)]

210061741, I took your advice and checked the spark plug. I don't know how to use a voltmeter, but the plug was wet. On a whim I replaced the plug, to see if that would help. Great success! My friend who installed the plug had removed the top contactor bit, said it wouldn't fit and should be fine without it. But then I replaced the spark plug wire with an upgraded one anyway. It must not have been making contact. However, I've since discovered some new problems:

1)Leaky fuel valve. Flooded my carb when it wasn't even turned on! I've yet to find a perfect spot to put it in so I'm just disconnecting it each time. I bought an upgraded one that feels much better but I can't get it to fit on with the beefy upper frame. :-(

2) Engine is missing strokes. It seems to work better when I'm not giving it as much throttle, but it still is. This results in a pretty shaky ride. At first it took off nice and soooo smooth, then I guess it must have loosened up.

 

[210061741]

Glad to hear you got your spark problem straitened out.

Now your not missing strokes your 4 stroking.

That's what happens when the engine gets too much fuel.

You said the carb was leaking so i would get that under control first.

You may need to take the bowl off the carb and bend the little brass arms down just a hair more.

That makes the float close the needle valve sooner.

Then the carb shouldn't leak if the float is right.

After you haqve that under control if it is still 4 stroking you will need to unscrew the top of the carb.

Take the slide out and compress the spring and get the needle out.

Move the clip up 1 notch at a time till it runs right.

Also check the nut that keeps the choke attached to the carb.

If it's loose the chocke will close from vibrations and thn i will 4 stroke.

Good luch

 

[(Ian)]

Thanks again. Unfortunately I got on my back just an hour later and had the same problems I originally did. :-(

 

[210061741]

Well it sounds to me like the plug is fouling out.

I bet if you take a razor Blade and scrape the electrodes a little and set a smaller than normal gap it will start up.

And if it dose it's that pesky ground wire coming off the side of the coil through the bakelite and soldered to the steel plate.

Get it running with the magneto cover off.
Look at the coil and see if it is arching out somewhere.

Other posibility is your carb is filling the engine with gas when it leaks.

Causing it to flood out right away.

 

[(Ian)]

It wasn't flooding this time. I took the carb apart and shook the fuel out after it was flooded, and it hasn't happened since. I think it was flooding because the engine wasn't really burning it. It made noise, but the muffler wasn't getting too hot and there was no smoke.

 

[210061741]

It wasn't runnin thats 4 sure.

You will see some smoke.

I'd be pretty positive you willfind that the coil is bad.

Not the cdi but the coil.

The cdi is the black box the coil is under the little rectangular cover on the engine.

Try this.

Take the spark plug out.
Use a new spark plug like a NGK B6HS.

Put the Spark Plug in the wire.
Place the threaded end on bare metal of the engine.
Walk the bike forward real fast and see if you get a good blue spark.

If it's more of an orange color or no spark at all it's a bad coil.

I have 3 or 4 bad coils from new engines. It's common

 

[Hajuu]

Sounds to me kinda like an air leak. Air leaks either on intake, exhaust, or on the head will cause immense loss of power, but usually only under high load.

Or the clutch maybe, but if its going full speed downhill and accellerating to full revs, then it seems unlikely itd be the clutch or the electrics.

 

[will_start]

Can you stop and rev the engine ?
thats my test if my bike is working.

My electrical plug test is crude but works.
Drink six beers, take the plug out, and hold it in your hand.
move the bike around, with clutch out, and feel the spark.
Feel the motor and how it sounds raw.
If my bikes not working, this gets me in touch with the motor.

Simple, No Pain, No Spark, just like an Ex Wife.

This should work even with highly compressed motors
as you've taken the tension out by removing the plug.
Smell the fuel and get a bit more high.

The beer helps stop the pain of the electrics.

Try it some time if you have the balls.

 

[SSGSPOD]

Spark not constant.....check rotor.

It may not be applicable to your case, but you should check it out.

My brand new engine had definite spark issues....no constant timed spark.
Pulled cover off, found deformed lock washer in the bottom, rotor was loose.
upon inspection, found the crankshaft key on the back of the rotor, rotor was freewheeling on the shaft, chewing up the lockwasher & nut, and stripping the threads on the crankshaft.

Rotor was hit and missing spark depending on how fast it was slipping on the shaft.

Motor must have been assembled on a Monday morning......

Will

 

[210061741]

I have seen several Grubee engines with no key or a key thats too small in the magnet.

It's a spark issue for sure.

Trust me i have fought it mayn times.