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Jon K.
Jon K., Small Engine Diagnostic Expert
Category: Small Engine
Satisfied Customers: 5818
Experience:  Gold certified Stihl tech, Service Manager for a rental/repair shop.Certified in most small engines
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i have a murray lawn mover with a briggs&stratton 12 hp synchro-balanced

Customer Question

i have a murray lawn mover with a briggs&stratton 12 hp synchro-balanced I/C motor on it. it is roling up an down in revolution all the time . allso when working full power. if you have a solution plesce contact a danish briggs and stratton fan because i have allways loved theese simple build engines Kind regards XXXXX Noldesvej 26 3000 Helsingør Denmark
Submitted: 5 years ago.
Category: Small Engine
Expert:  Jon K. replied 5 years ago.

Thank you for choosing Just Answer, my name is XXXXX XXXXX I will do my best to help you find the answer you need to resolve your problem.

Adjusting the needle at the bottom of the carburetor should have helped you out a little. Since it did not you are going to need to clean out the carburetor very thoroughly and rebuild it with a new carb kit, and then dial it in. Both of the adjustment screws should be set at 1 1/2 turns out from lightly seated as an initial setting.

If you can get me the model, type and code number off the engine I should be able to come up with a write up for dissasembling your carburetor

This is the location of where to find these numbers.

Briggs numbers