Sr3 lister irregular idle speed

[Martinb2347]

Morning all.  We have a air cooled lister sr3 and have noticed the last few times when the engine has been running a while that in neutral the engine seems to runs faster and slower.   Its a slight up and down but is noticeable.

 

Hope that makes sense....any ideas what it may be?

 

Thanks

Martin

[Steve56]

Possibly a small amount of air entering the fuel system. Or maybe a little stiffness on the fuel pump rack.

[Martinb2347]

Is it something that will work its way out?

[Tony Brooks]

17 minutes ago, Martinb2347 said:

Is it something that will work its way out?

 

If it's been stationary since the first lockdown then it may be a stiff rack and it may free itself with more running, especially if it gets hot. If its air and you have not done any servicing then I suspect it may get worse and eventually stop.