I know this may sound, and possibly be, a stupid question, but what is that black marker dot/mark that is placed on top of those Keihin diaphragm's? My old one had it there and the new one I bought today has one as well. I'm having a boat load of trouble with my '03 Wide Glide and I thought, probably wrongly, that a new diaphragm would correct my problem.........which it did not, by the way. XXXXXsee HDForums.com Rule 6XXXX

 

So what problems with the bike are you having? If the diaphragm is seated properly or gets pinched during install the carb will run like crap. Are you talking about the diaphragm on the vacuum piston or the one in the accelerator pump?

 

Well, it's the carb slider piston. It's the large black rubber oval attached to the slid and it's sits on top under the carb cap. My bike had a clogged pilot jet, so I took it all apart and cleaned it out. Well, it went to heck on me. The carb started flooding fuel into the slide area while I was watching it and if I cracked the throttle, the slid will just start to move up, the bike will rev and then that slide will stop and the bike will lose power, black smoke from here to eternity, raw fuel flying everywhere, bike bogging and my garage cat is still choking to death. I'm not dumb, but what the heck is going on here???

 

Fuel coming into the Venturi area and black smoke means your float is not closing the Float valve or there is junk keeping it from closing. I would start there. You should be able to watch the float valve close. Also, there is a setting for the float to make sure it closes. http://www.dansmc.com/carbs2.htm is a good link for learning the intricacies of your carb.

 

Yea, I would second what Hx3 said. Sounds like the fuel valve is not closing properly. I recently rebuilt my Keihin CV on a '04 FXDP, and that took it from running crappy, to running great (after a rejet). But I replaced the shutoff valve plunger (old one was slightly grooved) and reset the float level in addition to a day-long soak in carb cleaner & new jets.

Did you change the viton-tipped fuel shutoff valve (on end of float arm)? And were you VERY careful in setting the float height? Difficult to do properly (by the manual).

 

The slide is lifted by vacuum. There seems to be a hole somewhere cusing the springs on the piston to force it down, in other words vacuum isn't hoding it up. Here's a list of piston problems,piston atmosphere vent blocked, piston binding, spring binding, diaphragm cap loose-damaged-leaking, diaphragm pinched in lip groove, torn diaphragm, piston vacuum passage blocked, and enrichner valve open-not seated or leaking. the float is a seperate issue. You've got some work ahead of you, good luck.

 

www.harley-performance.com all the carb info you can ask for in a four course meall with a side of budlight and heavy metal music man!