I Have A 99 TB And The Only Mods I Have Done To It Are A K&N Filter And Clutch Kit. My Question Is That When I Go Ridding Around Slow For About And Hour Quater To Half Throttle It Starts To Make A Pinging Noise In The Engine What Would Be Causing This Or Is It Normal. It Dosent Do It If I Go Ridding Real Hard.

 

Pinging usually comes from a lean mixture. Since it's at 1/4 to half throttle you could try raising the needle a step (lower clip) and maybe richen the air mixture.

Check you plug, if it's on the light side this is probably it. Put a new plug in, run up to half throttle and kill the engine and coast to a stop before you check.

 

Just for the record contrary to popular belief low octane or sorry gas will also make the 250 ping



Thx RON

2000 Xplorer 250
Rcr stage 1