[ERICO]

Hi folks,
I am in an allotment association in Nottingham and we have a sick Mountfield Rotavator with Briggs and Stratton 5hp engine. After problems with poor starting and no power I have replaced pump diaphragm, checked jets, replaced kinked throttle wire and can now get it to start but run only at a fast tickover. Cuts out when try to increase throttle. Suspect jet still blocked or  poor adjustment of governor linkage. There are some links on "fixing problems with briggs and stratton+small engines" to governor linkage but none same as fitted. There is only one lever up from throttle wire slider/rack/sloppy spring assy under tank to bell crank on carb body. When stopped the throttle butterfly at carb is fully open, moving throttle lever does not move anything at carb. The "sloppy spring " in linkage under fuel tank has elongated loop one end and appears undamaged and in correct location both ends. I have tracked down a machine manual from Mountfield UK office and also basic engine manual (13000 series) but no detail on maintenance / setup for this governor linkage on rotavator. Can anyone explain how it should work or how to setup. Otherwise engine and machine fine!!  Thanks

[R Tallentire]

Sorry to be a bit slow with a reply, I tend to think of the M1 when I see Mountfield, they had a “vertical crankshaft” engine, which I don’t know a lot about.

Anyway, I suspect your mixture may be wrong, Get it up to running temperature, set it to half throttle, and turn the needle screw out until the revs start to fall, then back in until the revs fall again, then out again until half way between. If it still coughs when you open the throttle turn the screw out a little more, not much, a sixth of a turn or so, and check again.
If you do need to adjust the governor, slacken the pinch bolt at the bottom of the lever on the engine. Hold the throttle lever on top of the butterfly in the wide open position and screw the spindle sticking out of the crankcase clockwise as far as it will go, then tighten the pinch bolt again.