Tuning Diagnostic Help needed

[Chrisingippy]

Ok, so I went out this morning to adjust the carb to find this situation... not what I was expecting. The fuel was turned off, but not exactly pointing to the closed properly..
I pulled the spark lead to have that come apart in pieces as well. I'm wondering if the carby float has been my issue all along now? A couple of times I starting cold, it has fired and run at a fast idle (no choke) for about 30 seconds before slowing down... perhaps fuel leaking into the crankcase?
Ive been cranking it over, plug out and shooting a lot of fuel out the spark plug hole.. any other precautions I should take?

 

[Joshyaddow]

I'm having issues with my engine revving super high when I pull in the clutch the motor is a YD100 also having issue with starting it takes a bit and alot of peddling to get it going and when driving at low speeds seems to studder a bit any thoughts

 

[gary55]

I'm having issues with my engine revving super high when I pull in the clutch the motor is a YD100 also having issue with starting it takes a bit and alot of peddling to get it going and when driving at low speeds seems to studder a bit any thoughts

Air leak, hung cable, or slide in the carb sticking or installed improperly. If no leaks found and cables and slide are good possibly a bad or disloged crank seal.

 

[Joshyaddow]

Crank seal is the bottom end of motor where it splits in the middle correct

 

[gary55]

Crank seal is the bottom end of motor where it splits in the middle correct

That is the engine case gasket, but it is also a posibility so good call. These can cause such a problem and it is usually easy to see because there will be fuel/oil seeping from the break in the gasket. More common is the crank seal seen in pic. below. They are sometimes not properly installed and get damaged or pop out. It's usually the one on the magneto side, but sometimes the gear side as well.
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[Joshyaddow]

Yeah there is no oil/gas leaks anywhere on the motor

 

[gary55]

Yeah there is no oil/gas leaks anywhere on the motor

So the yz has a 1 piece cyl./head right? no chance for a leak there. If all is tight on the outside. No intake leaks or base gasket between the cyl. and case. Cable ans slide is all good. No leaks at the case gasket then seals would be the next place I looked. This is a case gasket leak. Could be anywhere along the split. Only place you won't see it is if it is where the case and clutch housing meet.
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View media item 61452

 

[Joshyaddow]

Yeah its a YD100 so the head and cylinder is all one piece and I have checked the motor top to bottom no oil/gas leaks the only the that really isn't sealed good is the gas cap it has a weak seal

 

[wan37]

Crank seal is the bottom end of motor where it splits in the middle correct

Crank seal is on side of engine behind magnet and magneto.

 

[Joel beller]

That is the engine case gasket, but it is also a posibility so good call. These can cause such a problem and it is usually easy to see because there will be fuel/oil seeping from the break in the gasket. More common is the crank seal seen in pic. below. They are sometimes not properly installed and get damaged or pop out. It's usually the one on the magneto side, but sometimes the gear side as well.
View media item 61418

I had that issue with my bike berry motor. the crank shaft seal broke and flooded my magneto which caused my motor not to start until I replaced the crank seal.. bought new one online got two of them for $5 plus had to replace my magneto cuz it was soaking wet with fuel and oil and would not produce electricity.