This is a truly perplexing situation for me. My 26EFI which has been realy reliable for 1500+hours has been giving me fits lately. Actually it started last year about this time. The motor would be running great on one job and then the next job I would fuel up and shortly after the thing would drop rpms and then increase. It would smell like the motor was loading up (fuel exhaust smell rich). The R's would go up and down but the engine would never quit, it would do this with or without the blades engaged. BTW this is on a Walker GHS with the 42 deck. The funny thing is that I may have a heck of a time on one property with it doing this and then the next stop it will run with absolutely no problem. It is truly an inconsistant problem that has me scratching my head. I thought it may have been a dirty fuel filter and replaced it. I took the fuel pump out of the tank and inspected it and cleaned the tank and screen. I checked the best that I could for wiring issues and still think it may be wiring but I am really stumped. When it is doing this I sometimes play with the linkage to increase the r's a few times and it seems to make it go away. Almost like if the choke is stuck on an old vehicle but this is an efi. Can anyone throw some ideas my way, I will listen to all. I know that I can take it to my dealer but I am so swamped that this ain;t happening until it isn't running at all or I get a rain day. Thanks.