I have a 2003 Low Rider (Carbed) with 15K miles on it. Ran fine when I put it away last year but wouldn't start when I tried to get it out in the spring. I didn't have a chance to look at it until recently and diagnosed a bad Crank Sensor. Replaced the sensor and it starts right up but there is still something not right.


I started the bike and it ran fine while warming up with the choke pulled out but as I reduced the choke it started running a little rough and would not idle. It would get down to about 700 RPM and then stall. I tried increasing the idle speed but now it is back firing through the carb. Any suggestions on where I should start diagnostics for this one?

 

Sounds like the carb has some fuel jelly in it from sitting. I would pull the bowl off and see what's in there clogging things up.

 

I'm thinking varnish. What I do is get a bottle of stp gas treatment and put half a bottle in the tank, fill er up with premium and putt for awhile. It won't hurt it and is quite often a cheap fix

 

New gas, disassembled and cleaned the carb. New manifold gaskets (per suggestion from other site. Any other thoughts. I don't mind fixing things but diagnostics can be a pain in the back side.

 

Check the vacuum hose from the carb to the fuel petcock. The petcock is vacuum operated (vacuum to open). Fresh fuel with some Seafoam in the gas. Like previously mention the carb maybe varnished up if the gas didn't get some kind of stabilizer in it.

 

Checked the plugs and it was definitely running lean on both cylinders. I decided to take the carb apart one more. Cleaned the low speed jet with a fine wire and more carb cleaner and that seems to have taken care of the issue. Runs great now.