So, I finally got the CV carb kit from CV Performance. I'm doing this for a friend on his 99 Fat Boy. Carb is stock are far as I know and he has aftermarket A/C and Exhaust. So, I went to check it out the other day as he is getting crap gas mileage. Like only about 70 miles on a tank. Pull the A/C off and crank the bike up. When you crack the throttle a mist of fuel blows out of the carb. Is this normal for this bike? I checked my bobber and it does not do this. Any ideas?

P.S. I'm thinking the float is out of adjustment????

 

I have nothing to add except 14 MPG is hard to believe, assuming its a 5 gallon tank. I would think you will get some mist with out the air cleaner up on cracking the throttle until the slide opens, I think you need to verify whats in the carb now..

 

yes, 5 gal tank. I can't confirm the mileage just going on what my friend told me. I'll know what is in the carb tomorrow evening.

 

The gas that squirts out...where is it coming from?

 

if it's coming from the accerator pump it's cool IF it's shooting into the carb throat. I was getting bad mileage, not that bad but about 32 mpg an my choke cable was sticking open. I replaced it an now my plugs don't look black after 3 tanks of gas.

 

FWIW, IMHO I wouldn't worry too much about what it's doing now. Pull the carb, strip it down, clean it. The one thing the CVP kit doesn't include that you might consider is replacing the inlet nipple ($20 m/l at any MoCo dealer). The stock one (combination of plastic and metal) is *****. The single-piece, brass one is much better.

The CVP kit includes a new needle valve. Put it in and set it carefully. Put the whole business back together using all the new CVP seals. Go through the CVP instructions to establish a starting point for the tuning. They will tell you how many turns on the mixture screw and which jets to start with. Once you get all that set up, you'll be close enough that the bike should run, so put it on the bike and go through the rest of the tuning steps from the instructions.

This thing with the fuel squirting out sounds weird. Verify that the accelerator pump nozzle is in fact aimed toward the inlet. If it isn't, that's a real head scratcher.

I don't think it's even physically possible to have actual mileage as bad as described. The bike would have to be set up impossibly rich to stuff that much fuel into the engine, so much so that it probably wouldn't even run. If those are true numbers (70 miles/tank), that strongly suggests either fuel leak or a leaky needle valve, possibly combined with a no-longer-functioning (always on) vacuum activated petcock (you'd expect to see a substantial puddle of fuel on the ground every time it is parked). If the needle valve isn't seating properly, he could be losing fuel through the overflow continuously while running down the road.

The needle valve will be replaced with the CVP valve, so that should get sorted. I'd also go ahead and get rid of the vacuum petcock, as well as replace the fuel line.

 

I did order the brass fuel inlet nipple. I went through that with mine. I'll get it set up and let ya'll know the outcome. I too suspect the fuel mileage but, like I said, just going on what he told me. Thanks for the suggestions, every thing helps.