Motorcycle Repair: Sputtering and stalling, honda shadow aero, vent hoses

Question
Hi Mark,

Ok, here is the scenario.  Was riding along just fine.  Pulled over
to take a break and when I went back to start my bike, It's a
1999 Honda Shadow Aero VT1100, it wouldn't do anything.  I
had the bike jumped and it started immediately.  The next
morning the bike wouldn't start however it at least tried to turn
over but the battery died as it tried.  I got it jumped again, on
the way to the Honda dealership the bike started to sputter and
stall.  The bike sputtered and stalled all the way, about 5 miles.  
Replaced the battery and had the charging system checked out and it
all checked out ok.  The tech test drove the bike and didn't feel the
sputtering, I then took the bike home, no sputter.  Problem
solved, I thought.  Went out of town for a week and wanted to
take the bike out, started right away, however here comes  the
sputter and stalling again?  What do you think the problem is?

Whew that was alot.  Sorry for the length.


Beau

Answer
Hi Beua,

I welcome long descriptions, thanks. The more details provided, the more accurate the reply. Many people send me a single sentence and expect their problem solved. lol

The sputtering may be a result of water or other contamination in the fuel. It may be a partially obstructed fuel or vacuum line. It may be a defective electronic component. It may be a varnished carburetor. It may be a carb or fuel tank venting problem.

There's several posibilities to be investigated.

I would start with examining the spark plugs. Read the appearance of the plugs to learn a little about what is happening during the combustion burning process.

Perform a cylinder compression check, followed with a leak-down test if necessary. These would determine the sealing properties of the combustion chambers (condition of the engine).

Check fuel and vacuum hoses for defects, pinch or bend, and leaks. A weak vacuum hose may collapse when engine is running.

Check carburetor atmospheric vent hoses for obstructions (same as above).

Check fuel tak vent hoses for same. Check fuel cap vent for obstructions. Check fuel pump operation.

The testing procedures listed above can be found in the service manual.

Was the VT1100 stored for any periods? Was gasoline stabilizer added?


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Respectfully,
Mark Shively