Re: Mower throttle fault

[Dave Liquorice]

> Found that the throttle doesn't have any effect except run and stop

>> and also doesn't directly move the levers on/near the carb. It moves = a >> plate against a spring on the opposite side of the engine. >> When the engine is hunting, a c. 2mm move of the little lever on the = >> carb gives full revs and no hunting. What I don't know is the method = >> of controlling the revs - as the engine hunts the lever on the carb i= s >> moving in time to the hunting.

The engine speedis normally controlled by a vane in the draft from the fan near the recoil starter. Engine slows draft drops, vane moves, opens= throttle, draft increases etc. Thesprings and linkages associated with this are uselly very sloppy and not easy to really follow what is going =

on with engine stopped. It might just be a spring in the wrong place/broken or similar for a linkage including bent.

Change the carb diaphragm - about =A33.50 (Amazon) - and clean the air= > filter

That is another possibilty our mower got one of the little flap valves stuck open and that made the engine hunt. Found it when I carefully took= the carb off the tank, put back ensuring flap valves in right place and =

decent overlaps etc. That was a number of years ago now...

A McCullock (McCulloch?) probably has a Briggs & Stratton engine their website is pretty good with full manauls etc. Bu may not cover the throttle linkages as that is really part of the mower not the engine. Tr= y the McCulloch site?

[Davey]

B&S are very helpful, they sent me by return the manual and parts list for an old engine on a Hayter that was not listed on their website for download. It had very useful info on carb. settings etc.

--=20 Davey.

[PeterC]

Thanks for all of the suggestions. The other sources of information and spares I'll follow up. I'll also check all the other things above and in other posts.