Most likely INSIDE the carbs.. The jets are just nozzles. Having clean jets does not mean the rest of the carbs plumbing is clean.

Is your fuel pump working? By your description I would start there. The bike has a pump BECAUSE, gravity cant supply enough fuel to properly run the bike.

 

Is your fuel pump working? By your description I would start there. The bike has a pump BECAUSE, gravity cant supply enough fuel to properly run the bike.

Ordinarily, I'd agree with you. But '04 and newer models, though identical engines and tanks, got rid of the fuel pump altogether and let it be gravity fed, so that precedent says that a gravity feed does supply enough fuel.

 

Your bike is 2003. The later model may be gravity fed, but I'll bet there are difference in the fuel line size and or jetting and or fuel flow rate through the carb ports and passages and fuel pressure requirements. My bike will RUN via gravity feed, but it starves for fuel at high throttle, high load conditions..

 

Yup, plenty of people get rid of the fuel pump on the 03's.

Did you inspect the vacuum slide?

Also, are the butterflies opening on the hypercharger? The vacuum line that opens those are notorious for cracking and needing to be replaced and maybe now it's not getting enough air.

 

A quick inspection of the vacuum slide didn't reveal any scratches or damage, though I'll go over everything a little closer tonight. The butterflies do open on the hypercharger, so I doubt it's being starved for air but that is something to consider.

I suppose the next course of action is to soak the jets and the entire carb in cleaner and then blast it out, hopefully that takes care of it. If not, I suppose I'll fiddle with the pilot screw and/or adjust the floats.

 

My 04 shadow petcock has a fuel line the size of a coolant tube going to the carb.

Yours needs the pump. Put it back.

And just because jets look clean doesnt ran they are, if there is varnish built up on the side walls of the jets it will supply far less fuel and have no power at speed.

Its usually very difficult to clean the jets without damaging the side walls inside. Chemicals don't do s goof enough job. Clean the rest of the carbs with carb cleaner and compressed air and replace the pilot and main jet with brand new ones. Seriously they are like 2-5 bucks at the dealer and most certainly in stock at most places. For exactly situations like this.

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You might want to jump over to vtxcafe and do some searching. There are a lot of guy's that have eliminated the fuel pump on early models, you might have missed something.

 

The needle and jets are currently soaking (and making my bedroom smell awful, reports my girlfriend). One thing I noticed though: the bike has a hypercharger intake and Vance&Hines exhaust, but the stock needle with only one washer. I could clean the carb all day but if the jets and needle aren't adequate for the air and exhaust modifications, I won't make any progress. So I found a DynoJet jet kit on eBay for ~$50 and pulled the trigger. That should be here next Wednesday. Any suggestions of other things to check/fix with the bike in general while it's just sitting there without a tank or carb?

 

On mine (an 09) there is a brass filter at the inlet to the carb that you might check. If you can cancel that Dynojet kit and get the Factory pro kit as they are MUCH easier to tune with and generally much better results.

 

I second getting the factory pro kit. Easier to tune. My bike had the dj kit in it when I bought it. Bought the fp kit and a stock spring and it was a piece of cake to dial in and the throttle response was so much smoother.

 

I've read good reviews of both DynoJet and Factory Pro, but of my friends who ride DynoJet is the only one they specifically recommended. Time will tell.