Carb, Fuel pump, or Hydraulic Tappets?

[ChromedOut]

My 97 Honda Shadow Spirit VT1100C makes a loud ticking noise while idling, regardless of engine temperature, which I attribute to the valve tappets. The noise goes away as soon as I start moving above 10mph or so and comes back at idle. I have isolated the sound to the front cylinder head, using a screwdriver as a stethoscope. This alone is not that big a deal, but I mention it because it may be related to the larger problem...

The bike seriously bogs down at 85mph in 5th gear. Any more throttle input at that speed causes loss of power, deceleration, and the engine gets quiet except for intermittent popping sounds. The only way to recover is to ease off the throttle. The bike reacts similarly at the top of each gear, i.e. 30 mph in 1st, 50mph in 2nd, 65mph in 3rd, 75mph in 4th.

When I turn the ignition to "ON", the fuel pump does not come on for 2 seconds to fill the float bowl, as stated in the Clymer manual (The Honda manual does not mention whether or not the fuel pump should come on). After the bike is running, I can feel the fuel pump pulse, so I know the pump is running, but I have not done a fuel flow test yet.

Additional supporting info - The previous owner often let the bike sits for weeks or months at a time. The exhaust has been modified to straight pipes (I don't know if the carbs were re-jetted). Fuel economy is 35mpg at highway speeds. The bike backfires on deceleration.

Questions -
1) Could a sticking tappet cause lack of power at high rpm and high load?
2) Could it just be that the carbs need cleaning? (I bought SeaFoam and a new fuel filter and will be trying these next)
3) Could the modifications to the exhaust cause any of this?

[Gadjet]

If the exhaust was modified and no adjustments were made to the jetting and mixture, then it may be that you are running a bit too lean - this will cause the popping/backfiring on deceleration.

As for the fuel pump not coming on right away, I wouldn't worry about it too much. Your float bowl shouldn't be empty that it needs the fuel pump to come on right away to give it enough gas to start the bike.

[oldschoolorange]

Defenitly check into the exaust and fuel delivers issue. putting straight pipes on a bike can actualy turn the exaust into a vacume causing the intake aic/fuel charge to be sucked out during valve overlap. Try riding with the choke on a bit, it will richen up the mixture. But yeah put on proper exaust, bikes can still be loud even with a baffled exaust, you do need some backpressure for an engine to function properly. check in the manual on how to do a back pressure check on your particular bike, if it dosent you might have to install a test port in your exaust pipe.

[niterider]

I had a very similar problem with my V-750 vulcan. Since the noise was not consistent, I thought that the problem was the lifters. It turned out to be the cam chain self adjusters. I bought two adjusters replaced them a nd the noise is gone. The mechanic at a shop helped me find the problem. I have a brand new lifter that I did not need to use in my desk drawer.

[colorado58]

i agree with oldschool, sounds like you are running realy lean at high revs

[thespirit]

Just wanted to also say i would look at the carbs not being jetted properly to the new exhaust. The ticking noise is probably just the valves not being adjusted properly. If it's a really loud ticking noise, adjust those first and then take it for a test ride. I would definately have your carbs rejetted though.