Briggs and Stratton 5hp wont start, senior help needed

[makallio85]

Mower: Murray 5/25 (which you sit in seat and drive it)
Engine: Briggs and Stratton 5hp (130902-1237-01) with pull cord
Problem: Wont start - or at did before.
Video: https://streamable.com/ufybgh

It is strange. I got this mower as it was not running very well. Poor performance, rpms humming, suddenly just dying etc. Backfiting through exhaust and carburetor.

Now it doesnt start up anymore at all. With choke on it at least coughs and backfires. Without choke, nothing. Until i spray starter fluid directly to intake or spark plug.

What has been done:

• changed fresh fuel
• removed air filter for debugging purposes
• cleaned carburetor and fuel tank, replaced diaphragm
• replaced spark plug
• checked flywheel key
• lapped both valves, and adjusted valves according to the specification
• checked for compression, which is around 90psi

I really cant get it anymore. My only gues would be that timing is still incorrect but what could cause it? Especially taking into account thati have only removed cylinder head and valve cover.

Could it be leaking gasket? Sounds like a long shot to me as psi is quite okay i think.

Any help appreciated. Thanks!

 

[Rivets]

You are going to have to remove the tank and carb, as a unit, very carefully without tipping. Then remove the carb from the tank, again without tipping. The reason I want you to do this is to check to see if you have fuel in the small auxiliary tank inside the main fuel tank. No fuel in the auxiliary tank means the pump is not working properly or the tank is worn, not allowing for a good seal between tank and carb. If there is fuel in the auxiliary tank this indicates your carb jets are clogged, which means a good soaking and cleaning again. This manual may help you out. https://docs.google.com/open?id=0B6NaqjIxWV1ycG8wd0s3Z2Q2X00

 

[makallio85]

Hi thanks. Will check.

Just wondering that if the problem would be engine not getting fuel, wouldnt it run for a while with starter fluid sprayed directly in to the intake (carb and tank is currently taken off already) or combustion chamber?

before adjusting and lapping those valves, it did run at least. Now it doesnt run anymore, just coughs and backfires.

 

[makallio85]

Hi. Now lets put this on hold. It has been combination of several issues and reinspecting flywheel key, revealed thay is was shredded. I will replace it and lets see.