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Briggs Quantum 190cc hard starting

#1

N

nbpt100

I am working on a Briggs Quantum 190cc engine with auto choke. It has hard cold starts. Requires up to 8 pulls. Hot starts are usually 1, maybe 2 pulls. Once it starts it runs ok. Seems to have adequate power. The auto choke seems to be set correctly and positions the choke plate as it should. I Cleaned the carb and inspected for intake leaks. Valve lash is normal. Removed head and inspected everything. Valves have some small play in the guides. The cylinder wall is in good condition. Installed a new Champion J19LM plug and set magneto gap to .010. Changed the oil with SAE 30.

I leak down tested and found 10% leakage. This is not perfect but it should still start and run reasonably. It pulls relatively easy so I do not suspect a sheared key.

Any thoughts on why it won't cold start with fewer pulls? Is it caused by the slight compression loss?


#2

B

bertsmobile1

Does the choke plate cluse fully ?


#3

N

nbpt100

Does the choke plate cluse fully ?
yes


#4

Roy405

Roy405

I am working on a Briggs Quantum 190cc engine with auto choke. It has hard cold starts. Requires up to 8 pulls. Hot starts are usually 1, maybe 2 pulls. Once it starts it runs ok. Seems to have adequate power. The auto choke seems to be set correctly and positions the choke plate as it should. I Cleaned the carb and inspected for intake leaks. Valve lash is normal. Removed head and inspected everything. Valves have some small play in the guides. The cylinder wall is in good condition. Installed a new Champion J19LM plug and set magneto gap to .010. Changed the oil with SAE 30.

I leak down tested and found 10% leakage. This is not perfect but it should still start and run reasonably. It pulls relatively easy so I do not suspect a sheared key.

Any thoughts on why it won't cold start with fewer pulls? Is it caused by the slight compression loss?
If it's overhead valves. Adjust the valves


#5

N

nbpt100

If it's overhead valves. Adjust the valves
Thanks for your input. The Briggs Quantum engine is a flat head.


#6

olds394

olds394

how do you I’d a quantum?
Any codes to look for on the blower housing?


#7

Scrubcadet10

Scrubcadet10

how do you I’d a quantum?
Any codes to look for on the blower housing?
Either above the spark plug, or above the muffler.
Should start with the digits 12xxxx xxx xx


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