Our bike is an 03 FXDL, Vance&Hines BigShot Staggered pipes, SE stage I air filter kit, SE plugs/wires and dealer re-jetted. Bike has run absolutely perfectly since I took it new off the dealer showroom floor.....now have 17600 miles. No other engine mods.

A couple of days ago I decided to put on one of the chrome HD carbureator top covers. Mod went fine....did not have to remove the diaphragm........everything bolted right back up and she started fine. After starting, a normal idle was reached of 950-1050 rpm. When I made a short run and came to my first traffic light [+/- 2 miles] engine idle would not drop below approximately 1300-1400 rpm. Occasionally it would be higher...........this occurred at several stops. After stopping at the market the engine fired back up without using the enrichener and settled in at the normal 950-1050 range. First stop light after getting up to about 3rd gear.......back to the 1300-1400 range. I know this is too high...........

I am thinking that if the diaphragm were damaged that I would get normal 950-1050 idle but would not be able to put on any throttle.....I think I am right on this. Anyhow...........

What could cause rpm to be too high after being in motion yet not affect sitting still rpm [again, which is normal].

I am kinda stumped here.

Anyone got any suggestions?

 

sounds like a vaccum leak. try sprayin some wd-40 around the carb and intake it will help determine if you have a leak.

 

Recheck to see if the lip of the diaphran is seated properly into the body of the carb. They do grow with the contact with fuel and sometimes look like they are seated, but untill you feel the cover drop in place like it should be , it can cause you problems.Just remove the screws in the cap and move it slightly in circles to see if you can feel it drop into the lip.

 

WD-40......................hmmmmmmmmmmmmmm.....


I did remove the cover to check for any malformation of the diaphragm..........and the cover seemed to drop right into place as it should....[both times]........still though, I can't help but think I may be missing something......Thanks for the advice TCSTD.....looks like I got more diggin' to do huh?

 

Suffice it to say , my IQ must have somehow mysteriously gotten divided by 3 or something.................

I did damage the diaphragm when I put the new chrome cover on the carb...............I pulled the whole thing again and with the right light found that I had torn the diaphragm at the 12 o'clock position when I put the new cover in place.

Thanks for your help on this TCSTD.........now, its off to one of my 3 local HD dealers to see if I can get a replacement today.

Thanks again