I have a '99 FLHT (carb'd) and it has developed a nasty backfire (through the carbeureter) while starting the bike. Once I get the bike running it runs great, from idle to WOT and if I shut it off, it will start right back up if it's still warm but it really is hard to get her started. I'm guessing it may be a problem with the enrichment circuit in the carb but I would like to know if I'm missing something before I tear the carb apart.

 

Check the VOES hose between carb/manifold and the VOES by your enricher ****.

 

VOES? I don't know what that is, but please help me out and explain. I appreciate it.

 

I had a 99 FLHT and I loved that bike. Mine would always crank if pulled out the enricher and let it idle for 3 to 4 minutes. If it started to spit and sputter when taking off I knew it was time to clean out the jet or replace the jet. This might be your problem. Wouldn't hurt to take a look.

http://www.youtube.com/watch?v=Deh7UqqkbKc

http://www.youtube.com/watch?v=m0sZ3...eature=related

 

there is a hose fitting on top of the intake for a switch ( voes) , make sure the hose is connected at both ends and is not cracked or split- if you have a vacuum pump, check and see that the switch will hold 10 PSI

check for intake leaks at the heads.

while the bike is idling, spray wd40 through the red straw at each of the intake manifold/head joints- if the idle changes then you have found the location of the leak.

if the plug over the idle mixture sctrew has been removed, make sure that the idle mixture screw has not fallen out.


this problem would not indicate a fault or clog with the main jet


mike

 

Thanks for all the help guys I really do appreiate it. I'll pull the tank off tomorrow and check the VOES hose and hook up the mightyvac to the switch, and then it's on to the carb I guess. I was going to try the wd-40 intake leak check but I only got her fired up once I cant get her to fire up again. The crazy thing is that the one time I got her running since this started it ran normal, from idle to WOT, I even rode it down the street and back with no issues. So that leads me to believe it's not an intake leak. The accelerator pump is working and the slide works as it should when the bike was running on the stand. I shut it off and it cranked right back up. But when I let it sit for the night, no joy.

I also pulled the plugs and they looked good and the spark looks fine when cranked over as well.

I got 3 weeks to get some riding in before I deploy again so I'll keep crackin' and keep ya'll posted. The videos were a big help too, thanks again.

 

ok you have a mity vac- good.

try this first

the stock petcock has a vacuum line on it.

attach the mity vac and apply 5 psi or so to the petcock.

that opens the petcock and will allow fuel to flow to the float bowl.

this lets us know that there is fuel available when you first start cranking the cold motor.


any change ?

if it fires right up, this may tell us that when you are first cranking a cold motor, the float bowl is empty.

mike

 

No vacuum hose Mike, running a Pingel petcock to a SE 44mm (Keihin I think) HD part# 27932-99 is on the carb. I know there is fuel available when cold because the accelerator pump will squirt fuel when I twist the throttle before I try to crank it.

 

VOES = vacuum operated electronic switch. It is a pretty insignificant looking plastic thing that serves to alter ignition timing while riding. If it is disconnected, or the plastic hose is split, it can really mess up the engine, until you get up to a decent steady speed, when all seems fine until slowing down again!