I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance

On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.

brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance



dpb wrote:
On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.


Or the idle mixture needle is set too rich.

Rob

On May 5, 3:05 pm, trainfan1 wrote:
brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance


dpb wrote:
On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.


Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.

Or the idle mixture needle is set too rich.

I'd classify that as a carb problem...

On May 5, 1:39 pm, dpb wrote:
On May 5, 1:32 pm, brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.

It does seem to run smoother with the choke on just a little, if its
not choked it sputters and backfires, if its fully choked it just
dies. I've took the carb off and everything look fine. (This is the
second carb i've put on it)

On 5 May 2007 13:35:50 -0700, brian wrote:

On May 5, 1:39 pm, dpb wrote:
On May 5, 1:32 pm, brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.

It does seem to run smoother with the choke on just a little, if its
not choked it sputters and backfires, if its fully choked it just
dies. I've took the carb off and everything look fine. (This is the
second carb i've put on it)

Are the plugs the right type? Some burn hotter than others.
--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..

On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance


If it's really related to whether the PTO is engaged or not, I would
suspect a problem with the safety switch on the PTO, although it seems
to be acting backwards from what I would expect. When the PTO is not
engaged, the switch is intermittently causing the ignition circuit to
be interrupted; when you engage the PTO, the switch is not a problem.
Normally the switch fails the other way. Assuming the safety is part
of the PTO switch itself, this would be easy to check. Pull the wires
off the PTO switch and see if anything changes. You don't say whether
the behavior coming off a hill is with the PTO engaged or not.

"MarkL" wrote in message
ups.com...
On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance


If it's really related to whether the PTO is engaged or not, I would
suspect a problem with the safety switch on the PTO, although it seems
to be acting backwards from what I would expect. When the PTO is not
engaged, the switch is intermittently causing the ignition circuit to
be interrupted; when you engage the PTO, the switch is not a problem.
Normally the switch fails the other way. Assuming the safety is part
of the PTO switch itself, this would be easy to check. Pull the wires
off the PTO switch and see if anything changes. You don't say whether
the behavior coming off a hill is with the PTO engaged or not.


I like that diagnosis. The only other thing that I can think of that would
be related to PTO engagment is the governor.
And I can't explain how to adjust it.

On May 5, 7:03 pm, MarkL wrote:
On May 5, 1:32 pm, brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance

If it's really related to whether the PTO is engaged or not, I would
suspect a problem with the safety switch on the PTO, although it seems
to be acting backwards from what I would expect. When the PTO is not
engaged, the switch is intermittently causing the ignition circuit to
be interrupted; when you engage the PTO, the switch is not a problem.
Normally the switch fails the other way. Assuming the safety is part
of the PTO switch itself, this would be easy to check. Pull the wires
off the PTO switch and see if anything changes. You don't say whether
the behavior coming off a hill is with the PTO engaged or not.

I'll give that a try, i've also noticed that the AMP gauge has been
acting crazy. It usually stays right above 0 but lately jumps to bout
17 then down below 0. Don't know if that would have anything to do
with the PTO switch or not.

Sounds like it running just a bit rich on the main jet adjustment. Try
turning it down (in) a half turn.

--
Steve Barker




"brian" wrote in message
ps.com...
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance

dpb wrote:
On May 5, 3:05 pm, trainfan1 wrote:
brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.

Thanks in Advance


dpb wrote:
On May 5, 1:32 pm, brian wrote:
I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin. There
is some kind of a problem with the engine. When the engine is running
with blades off it sputters and backfires. When blades are on it runs
smooth. I have replaced air filter, fuel lines, fuel filter, plugs
and cleaned out the Carb. There is no sign of water in the fuel.
Also there are times it will bout die when coming off a hill, then
blow a puff of black smoke. Could it be the fuel pump is going bad?
Any help is sure welcome.


Running too rich -- first choice is choke isn't opening fully so it's
running partially choked, therefore a rich mixture. If that's not so,
then there's a carb problem.
Or the idle mixture needle is set too rich.

I'd classify that as a carb problem...



I'd classify

"choke isn't opening fully so it's running partially choked"

more of a "carb problem" than a normal idle mixture adjustment, which is
no problem at all, just a normal adjustment to be expected & performed
occasionally.

Rob

brian wrote:
On May 5, 7:03 pm, MarkL wrote:
On May 5, 1:32 pm, brian wrote:

I have a Craftsman DYT 4000 tractor with a 21 HP Briggs V-Twin.
There is some kind of a problem with the engine. When the engine
is running with blades off it sputters and backfires. When blades
are on it runs smooth. I have replaced air filter, fuel lines,
fuel filter, plugs and cleaned out the Carb. There is no sign of
water in the fuel. Also there are times it will bout die when
coming off a hill, then blow a puff of black smoke. Could it be
the fuel pump is going bad? Any help is sure welcome.

Thanks in Advance

If it's really related to whether the PTO is engaged or not, I would
suspect a problem with the safety switch on the PTO, although it
seems to be acting backwards from what I would expect. When the PTO
is not engaged, the switch is intermittently causing the ignition
circuit to be interrupted; when you engage the PTO, the switch is
not a problem. Normally the switch fails the other way. Assuming the
safety is part of the PTO switch itself, this would be easy to
check. Pull the wires off the PTO switch and see if anything
changes. You don't say whether the behavior coming off a hill is
with the PTO engaged or not.

I'll give that a try, i've also noticed that the AMP gauge has been
acting crazy. It usually stays right above 0 but lately jumps to bout
17 then down below 0. Don't know if that would have anything to do
with the PTO switch or not.

That's a significant observation. That indicates a short or near-short
happening

Does it go to 17 first and then below 0? That would indicate a very high
drain on the battery followed by apparently the charger ckt kicking out
until it cools, thus you see the battery drain and no charge, hopefully with
the battery protected.

If it goes below 0 first, THEN to 17, that would be consistant with a short
happening and then being removed, and the charger simply recovering the
batttery to its full charge. I've seen mine go to 10 to 12 Amps immediately
after starting the engine, but then it sits at about an amp or so the rest
of the time even with the lights on at night.

I'd suggest it's either:
-- The battery has gone bad
-- Or a wire is somehow being shorted to the chassis intermittantly. It'll
be the 12V wiring. In this case I doubt it'd be a safety switch because
they usually only ground out the ignition.
Might be time to give the wiring cable a good onceover along its length
from the battery to the farthest point, including all the connections. Make
sure unused plugs aren't bumping anything that could get inside it and short
them.
A favorite place for shorts I discovered in these is around the fuse.
Mine is just under the lip thru the access hole. I had a wire pull partly
out, letting it short to the chassis through a bunch of wet dirt/grass
buildup, apparently. Cleaned, taped, and OK after that. We use the 20 HP
Vtwin for mowing the side fields; it works well but is really dirty work.

HTH
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