520H engine racing

[Thetbone 3]

When I start my tractor the engine races, can't get it to stop without shutting off and re starting.  Then when running it will vary engine speeds, can hear that.  Ideas on what to do to remedy.

Thanks.

[WHX?? 48,853]

Start by cleaning the carb.

[Thetbone 3]

Will do thanks.

[peter lena 8,654]

@Thetbone  agree with @WHX?? on the carb clean , on any recent pick  up / recovery , start it up on a seperate gallon of heavily treated fresh fuel , also do an immediate  carb bowl drop , usually loaded with , fuel hose break down , crud , fuel tank probably loaded with debris , have 2 fuel filters on my 3  horses , large one close to tank , smaller one close to carb . new fuel hoses , drop fuel tank bottom valve , total clean out , personally  since adding  1 ounce of  STA BIL  fuel storage additive , there has been ZERO FUEL LINE BREAK DOWN , read that again , since replacing  lines /  and cleaning out  fuel set up , there has been NO DEBRIS  in my fuel filters , is that telling you something ? the additive has stopped the debris / fuel hose breakdown , repetitive    problems often show you the way , no crud in my fuel filters , quick starts , pete   

[Red-Bovine 309]

If "Racing" meaning running real fast, I would check to see if the governor spring is loose or off.

[lynnmor 7,321]

It could be a broken flyball spacer, see this website for information.  Of course check for obvious problems with the linkage or tampering, before disassembly.

[8ntruck 7,034]

520H - this one has an Onan with a 2 piece intake manifold?  Those are known to leak and cause surging.

 

If the engine is over speeding, I'd suspect a governor issue.

[Thetbone 3]

Great help, will look at all of these today, thanks again.