Motorcycle Repair: fowl plugs, honda vt1100, screw driver

Question
QUESTION: have 2003 honda vt1100 sabre.3 months ago it was running fine,now it has fowled out plugs and breaks up at about 50/60mph when I get on the gas.I dies as if the rev limitter is cutting in.Same after I changed all plugs.It will get up to speed very smooth if I don't give it the gas Very fast.Mufflers are black in color.Have been getting louder and louder since last year, about 16,000 miles in one year.Battery is good,haven't changed the air cleaner.Starts and idles very good.cant hear no skips.Takes off very good.Just when I punch it.Once i took out the air cleaner to see how it would run, and it would run good at low speeds,and break up when giving the gas.Only did that for one ride.Yes put back the air cleaner.But that is how it seems to be running now.
I did put a hole in both baffel's about 3/8 to 1/2 inch, with a screw driver last year.Im just wondering if the baffels are rusting out and the their is less restriction in the mufflers.
Tks
Johnny
e me at
conntaxman@yahoo.com
///will be jetting it up to the next size tomorrow.
6/6/07
any idea's would be nice to ease the mind


ANSWER: Johnny,
has the fuel system been cleaned, almost sounds
like water in the gas. Are the plugs fouled
with gas or oil? Are the plugs black (rich fuel)
or light color (lean fuel).
Having little backpressure can lean out the fuel mix.
Do a fast but safe run at the rpm where it misses
and kill the engine quickly. Look at the plugs
and see what color they are, that will tell
you if it is lean or rich on fuel.
See if the jetting helps, you can also
try raising the carb needles a notch
to richen the mid-range fuel.



---------- FOLLOW-UP ----------

QUESTION: Plugs are black in color,not wet.doubt if their is water,I use 93 oct.and have run it empty a few times. Yesterday was at my friends bike shop and he put in some fule additive and that didn't work either.It seems to be burning Rich.[black].But isn't that a cause of not enought back pressure?
tks
Johnny
e me at
conntaxman@yahoo.com

Answer
Johnny,
having little backpressure makes the mixture leaner
because you are getting more air than usual in and out
of the engine. The flow of exhaust can actually
suck unburned fuel right through the engine into
the exhaust pipe causing backfire or lean the engine
out so the fuel doesn't burn until it hits
the hot exhaust,again causing backfire.  
If the plugs are black you are getting too
much fuel or your compression is very low.
Check your air filter, or maybe a main jet
has come loose in one of the carbs.
Make sure the choke is working correctly.
Are your plugs the right heat range?