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Donald
Donald, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1800
Experience:  I have 25+ years of experience repairing 2 & 4 cycle engines
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I have a VICTA Motor Mower, fitted witha 550EX, 140cc, 4

Customer Question

Hello there,
I have a VICTA Motor Mower, fitted witha 550EX, 140cc, 4 stroke, Briggs & Stratton OHV motor. It was purchased recently from a Bunnings Store.
I have used it about 6 times and had excellent service from it until today.
The Motor stars instantly with the throttle set to the Start Position. When I draw the throttle back to the Run position, the motor fails to reach normal running revs, and the exhaust puffs slight black smoke. My guess is that it is running "rich".
Should this be covered under warranty? OR, Can I easly do something about this? Is there a "mixture" screw that I can adjust.
Thanks for your expected expert advice.
***** *****. ***** Sandringham. VIC.
email:***@******.***
Submitted: 11 months ago.
Category: Small Engine
Expert:  Donald replied 11 months ago.

Hello, and thank you for choosing Just Answer. My name is***** will be happy to assist you.

Expert:  Donald replied 11 months ago.

There is a possibility that your choke is not fully opening, after your engine starts. This is likely the reason for the rich running condition, and the black smoke.

Expert:  Donald replied 11 months ago.

Remove your air filter cover, and your air filter. Move your mower to a concrete surface, then start your engine. Check to see if your choke is fully opening.

Expert:  Donald replied 11 months ago.

Your choke is thermostatically controlled by a thermostat on your muffler. As the temperature of your thermostat rises, your choke should automatically open.

Expert:  Donald replied 11 months ago.

Check this, and we can continue from here. Thanks!