-Ralph-
20-10-11, 08:35 PM
I have a Mountfield SP470, with a Briggs & Stratton LS45 engine.
It has a carb very similar to this...
http://www.lawn-mower-shop.com/pic551.jpg
there is no manual throttle, you just start the mower and it maintains steady revs. If something is starting to stall the engine, it adds revs until it has overcome the resistance.
To do that the lever attached to the top end of the spring mechanism moves back and forward to open and close the throttle automatically (a governor of some description?).
The sprung mechanism has started oscillation open and closed, so instead of a steady brrrrrrrrrrrr at steady revs, I'm getting brum, die off, brum, die off, brum, die off. If I hold it still with a screwdriver I get steady revs, so the engine is fine, it's definitely a carb problem, or whatever it is that controls this throttle mechanism.
Any ideas?
(other than rip it off and put a manual throttle on which I am tempted by)
It has a carb very similar to this...
http://www.lawn-mower-shop.com/pic551.jpg
there is no manual throttle, you just start the mower and it maintains steady revs. If something is starting to stall the engine, it adds revs until it has overcome the resistance.
To do that the lever attached to the top end of the spring mechanism moves back and forward to open and close the throttle automatically (a governor of some description?).
The sprung mechanism has started oscillation open and closed, so instead of a steady brrrrrrrrrrrr at steady revs, I'm getting brum, die off, brum, die off, brum, die off. If I hold it still with a screwdriver I get steady revs, so the engine is fine, it's definitely a carb problem, or whatever it is that controls this throttle mechanism.
Any ideas?
(other than rip it off and put a manual throttle on which I am tempted by)