After 14000 miles of running good the bike starts running rich. Everything is fine and just out of the blue running along and the bike starts running like crap. Play with the PMS and it doesn't help. I tore into it and the plugs were black as can be. I did my SVS treatment and it was a little better but still wasn't running right. This didn't start until the weather got a lot cooler. I am starting to think the valves are sticking because of the cooler weather. It seems to run the worst around the range of 1300 - 1800 rpm like it did before I went to the 40 pilot. I tore it apart and blew the carb out with air and put the 35 pilot in place of the 40. I had to back the pms out a lot and tested it and it seems to have cured the problem. I can't figure why I have to go to the 40 pilot when the weather is hot and the 35 when the weather is cold. I wonder if they are screwing with the gas mixture again?

It is possible. They switch to a winter blend around here. I know my mileage drops when they do. I was always under the impression they would run leaner in cool weather than warm? Maybe I am messed up.

I thought that too because cold air is denser. I know that from my jet engine days. Just wonder after all the storms on the gulf if they might have cleaned up their refining process? I usually loose gas milage with winter gas too but I don't think they have switched yet. Never really know what the oil company's are doing anyway. They sure won't tell ya if they are doctoring their fuel or not.

Interesting. I would have never thought about mixture changes with seasons... HMMMM.

DNK

The Ethanol hasn't been increased to more than10%. has it Curt That winter mix messes with mine but have only had to adjust PMS in.

JavaWave didnt hit you with the crash and burn pic again did he?

lol. I was going easy on him, but since you asked.

I have the same problem up here in Pa, when the weather turns really cold my bike starts running really rich, I thought it was just me as no one else seems to complain about it, I tweak my PMS in 1/2 to 3/4 turn and it seems to help it a lot after a few days.
I thought it was just me....

When I flew ultralights, I was running a Zenoah G-50 -- 50hp @6,000 RPMs. In cold weather, take-offs were smoother and the engine ran really sweet and seemed a lot more powerful.

Wow.... Frank...ultralights... you've done a lot of things haven't you.

I'll bet you probably played Joseph in the Christmas play too!

No.... They never let me be in the Christmas play. (I was usually suspended from school for fighting)

I once mentioned wanting to be Jesus, and for some reason, the teacher laughed so hard, he had to hold onto his desk, and he had tears coming out of his eyes.