I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
certain rev count the bike is miss firing (losing power) when give
more petrol it go past the miss fire problem. I did replace sparkplugs
change petrol and oil filters but problem still exists. What else can
I check to rectify the problem?

On Nov 3, 12:10*am, beachball <tvst...@gmail.com> wrote:
> I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> certain rev count the bike is miss firing (losing power) when give
> more petrol it go past the miss fire problem. I did replace sparkplugs
> change petrol and oil filters but problem still exists. What else can
> I check to rectify the problem?

You might just have dirty carburetors because of deposits left in the
idle jets and passages as the gasoline evaporates while the motorcycle
isn't ridden every day.

When the idle jets are slightly plugged up, the engine will run better
at higher RPM, but when the idle jets get completely plugged up, the
engine will start and run at idle, but will stall when you twist the
throttle because it really needs the gas from the idle jets to
accelerate when the throttle butterflies are only slightly open.

There are carburetor cleaners like GumOut and STP that are available
in an aerosol can. They contain strong solvents like acetone, toluene
and xylene.

You can spray four or five ounces of the cleaner into a measuring cup
and then pour the liquid into a full tank of gasoline and just ride
until the carbs are cleaned out.

My favorite carburetor cleaner is Berryman B12 Choke and Carburetor
Cleaner.

It comes in convenient liquid form and a 15 ounce can costs about
$3.50 at Wal*Mart.

On 3 Nov, 08:10, beachball <tvst...@gmail.com> wrote:
> I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> certain rev count the bike is miss firing (losing power) when give
> more petrol it go past the miss fire problem. I did replace sparkplugs
> change petrol and oil filters but problem still exists. What else can
> I check to rectify the problem?

At what revs is it misfiring? No way of making a meaningful carb
diagnosis without this info.

Has the bike been laid up for any length of time?

On Nov 3, 12:10 am, beachball <tvst...@gmail.com> wrote:
> I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> certain rev count the bike is miss firing (losing power) when give
> more petrol it go past the miss fire problem. I did replace sparkplugs
> change petrol and oil filters but problem still exists. What else can
> I check to rectify the problem?

As TOG had already asked, what RPM did it miss at ?

When you pulled the plugs, were the electrodes on the
old plugs all the same color ? What color ?

On Tue, 03 Nov 2009 21:10:02 +1300, beachball <(E-Mail Removed)> wrote:

> I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> certain rev count the bike is miss firing (losing power) when give
> more petrol it go past the miss fire problem. I did replace sparkplugs
> change petrol and oil filters but problem still exists. What else can
> I check to rectify the problem?


Air cleaner filter(s)?
I would dismantle the carburators, blow out the jets and clean float bowls.

Greg.P.
NZ

On Nov 3, 2:39*pm, "TOG@Toil" <totallydeadmail...@yahoo.co.uk> wrote:
> On 3 Nov, 08:10, beachball <tvst...@gmail.com> wrote:
>
> > I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> > certain rev count the bike is miss firing (losing power) when give
> > more petrol it go past the miss fire problem. I did replace sparkplugs
> > change petrol and oil filters but problem still exists. What else can
> > I check to rectify the problem?
>
> At what revs is it misfiring? No way of making a meaningful carb
> diagnosis without this info.
>
> Has the bike been laid up for any length of time?

Misfire between 4000 - 5000 rpm

On Nov 3, 9:07*pm, Rob Kleinschmidt <Rkleinsch1216...@aol.com> wrote:
> On Nov 3, 12:10 am, beachball <tvst...@gmail.com> wrote:
>
> > I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> > certain rev count the bike is miss firing (losing power) when give
> > more petrol it go past the miss fire problem. I did replace sparkplugs
> > change petrol and oil filters but problem still exists. What else can
> > I check to rectify the problem?
>
> As TOG had already asked, what RPM did it miss at ?
>
> When you pulled the plugs, were the electrodes on the
> old plugs all the same color ? What color ?

Misfire between 4000 - 5000 rpm

On 5 Nov, 08:20, beachball <tvst...@gmail.com> wrote:
> On Nov 3, 9:07*pm, Rob Kleinschmidt <Rkleinsch1216...@aol.com> wrote:
>
> > On Nov 3, 12:10 am, beachball <tvst...@gmail.com> wrote:
>
> > > I have a Honda Shadow VT1100C 1996 problem, when I accelerate and on a
> > > certain rev count the bike is miss firing (losing power) when give
> > > more petrol it go past the miss fire problem. I did replace sparkplugs
> > > change petrol and oil filters but problem still exists. What else can
> > > I check to rectify the problem?
>
> > As TOG had already asked, what RPM did it miss at ?
>
> > When you pulled the plugs, were the electrodes on the
> > old plugs all the same color ? What color ?
>
> Misfire between 4000 - 5000 rpm

Given the relatively low revs of the Shadow engine, that's unlikely to
be pilot jets. As I asked before, has the bike been laid up for any
length of time? If not, and it was running fine before, then it's
*really* unlikely to be pilot jets.

It could be a dodgy electrical connection making and breaking at a
critical vibration period. Sidestand ignition cutout (if it has one),
and anything else in the ignition circuit, including the ignition
switch and where it plugs into the loom.

It would make life easier if you'd answer the questions put to you,
because if you don't, you're unlikely to get a solution.

On Nov 5, 1:54*am, "TOG@Toil" <totallydeadmail...@yahoo.co.uk> wrote:

> Given the relatively low revs of the Shadow engine, that's unlikely to
> be pilot jets. As I asked before, has the bike been laid up for any
> length of time? If not, and it was running fine before, then it's
> *really* unlikely to be pilot jets.

That shows how little you know about CV carburetors.

At idle, or very small throttle openings, the engine gets ALL of its
gasoline from the pilot jets, two of the three transition ports are
blocked off by the throttle butterflies, and the jet needle blocks off
flow through the needle jet.

The engine sucks less and less gasoline through the pilot jets until
nothing is going through the pilot jets at wide open throttle.

The engine needs the gasoline to come through clean pilots jets and
out the three transition ports just downstream of the throttle
butterflies.

If the pilot jets or the transition ports in one carb are dirty, but
clean in the other carb, the engine will be mostly running on one
carb, and then the dirty carb will start sucking gas past the needle
at higher RPM and it will start running on both cylinders.

On Nov 5, 12:20*am, beachball <tvst...@gmail.com> wrote:

> Misfire between 4000 - 5000 rpm

Well, when it misfires at 4000 ~ 5000 RPM, are you twisting the
throttle a lot, or just a little bit?

Your motorcycle has rubber diaphragms that lift a vacuum slide which
controls how far the jet needle is pulled up out of the jet needle.

The vacuum slide won't be lifted unless the engine is producing enough
vacuum
to use the fuel that comes through the needle jet.

This is to reduce hydrocarbon air pollution from unburned fuel.

Another possibility besides dirty carbs is that one of your vacuum
slides might have a small hole in the rubber diaphragm.