so this happens just every now and then, bike runs fine otherwise. Ultima 120 with Super G... it idles fine while sitting at a light but if there are a lot of lights and i have to sit for a long time at each one it will just shut off. no warning or stumble just shuts off,, starts right back up but if left to idle will shut off again. run it down the road and its fine again... any thoughts?

 

is the bike running rich?? black smoke out the exhaust? whats the RPM your idle is set to?

 

what year is the bike? does it have a vacuum operated petcock?

 

Check that little black accordion looking piece that is on your accelerator pump shaft.
They dry rot and start letting air into your carb.

 

Funnily enough my FX1200, bought new, would do something similar. It routinely idled by 4-stroking on the front cylinder, 8-stroking on the rear and, after a while would simply shut down, but kick back into life without trouble. It did indeed run a tad rich, however rode well in every other way and tinkering with the idle mixture or speed didn't improve things.

The chaps above have made good suggestions, I will simply add that it is worth going over the entire fuel system, such as checking tank and tap, fuel lines, VOES if you have one, float level, the usual stuff. And give it a hug, in these distressing times!

 

the high speed jet is a bit on the rich side but otherwise the carb is set perfect.

i like my idle slightly higher than most people, tach isn't working right now to check but it idles fine until it shuts off.

bike is a 98 FLHT and has an aftermarket (Accel) petcock, No Vacuum line

Carb is only 1 year old so pretty sure the advance boot is fine but a good idea to check it..

in fact thinking about it now i will go ver the whole carb and intake and double check tightness and for vacuum leaks.

thanks for the words of wisdom folks i appreciate it... the bike is only 2 years into a new build so everything is new with about 7-8K on the build...

 

yeah Mike thats a good idea to check everything for tightness and vacuum leaks since it was a new build

 

If it was fuel related I'm sure it would start to stumble or similar before totally cutting out.... Sounds more like electrical or ignition... What ignition is in it?

 

I was just going to ask the same question Hotrod

 

well right now i have a Dyna S ignition single fire set up.. the guy doing the build was not a fan of the electronic one that came with it so put that on.. i am planning on changing it back over when i have a chance.. i have everything to go back to dual fire and the Ultima ign