Well it didn't happen yet, but a neighbor brought over her 2003
Troybilt 8526 so I could see why it stalls after running for 5
minutes. Pulled off plastic cover shroud to work on the carb.
Noticed that the plastic shroud was molded with (3) bosses for
retention with extended head bolt studs, but only (2) head bolts were
headed with studs. Why you may ask??, well at some point the mfr
added an 120V electric start option and the standard Tecumseh starter
switch/receptacle combo has the cord leaving the housing directly over
a head bolt, leaving no room for a "stud" headed capscrew for the
third boss. Only problem is the plastic boss is still molded into the
cover and when bolted down with the two remaining head studs, it
tightly pinches the 120V cable going to the starter against a hot
cylinder head capscrew. Only easy fix I see is to trim the cover boss
to clear the 120V cable as it exits the starter switch. If you have
one of these take a look before you get zapped or at least use a GFI
outlet. Think I'll email a photo to Troybilt/MTD. By the way the
carb is a typical post '97 EPAised non-adjustable piece of crap. How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

On Jan 28, 1:05*am, oldjag wrote:
Well it didn't happen yet, but a neighbor brought over her 2003
Troybilt 8526 so I could see why it stalls after running for 5
minutes. *Pulled off plastic cover shroud to work on the carb.
Noticed that the plastic shroud was molded with (3) bosses for
retention with extended head bolt studs, but only (2) head bolts were
headed with studs. *Why you may ask??, well at some point the mfr
added an 120V electric start option and the standard Tecumseh starter
switch/receptacle combo has the cord leaving the housing directly over
a head bolt, leaving no room for a "stud" headed capscrew for the
third boss. *Only problem is the plastic boss is still molded into the
cover and when bolted down with the two remaining head studs, it
tightly pinches the 120V cable going to the starter against a hot
cylinder head capscrew. *Only easy fix I see is to trim the cover boss
to clear the 120V cable as it exits the starter switch. *If you have
one of these take a look before you get zapped or at least use a GFI
outlet. *Think I'll email a photo to Troybilt/MTD. *By the way the
carb is a typical post '97 EPAised non-adjustable piece of crap. *How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

They are trading one type of emissions (HC) for another (NOx).
If it's lean now wait till they try running it on E10.

Was the fuel vent in the cap plugged?

Dave

On Jan 28, 9:54*am, Dave__67 wrote:
On Jan 28, 1:05*am, oldjag wrote:



Well it didn't happen yet, but a neighbor brought over her 2003
Troybilt 8526 so I could see why it stalls after running for 5
minutes. *Pulled off plastic cover shroud to work on the carb.
Noticed that the plastic shroud was molded with (3) bosses for
retention with extended head bolt studs, but only (2) head bolts were
headed with studs. *Why you may ask??, well at some point the mfr
added an 120V electric start option and the standard Tecumseh starter
switch/receptacle combo has the cord leaving the housing directly over
a head bolt, leaving no room for a "stud" headed capscrew for the
third boss. *Only problem is the plastic boss is still molded into the
cover and when bolted down with the two remaining head studs, it
tightly pinches the 120V cable going to the starter against a hot
cylinder head capscrew. *Only easy fix I see is to trim the cover boss
to clear the 120V cable as it exits the starter switch. *If you have
one of these take a look before you get zapped or at least use a GFI
outlet. *Think I'll email a photo to Troybilt/MTD. *By the way the
carb is a typical post '97 EPAised non-adjustable piece of crap. *How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

They are trading one type of emissions (HC) *for another (NOx).
If it's lean now wait till they try running it on E10.

Was the fuel vent in the cap plugged?

Dave

The vent is probably clear, I ran a 1/2 pint or so of fuel out of the
fuel hose at the carb to see if there was any restriction, kink vent
issue etc. BTW around here it's hard to know if your getting E10 or
not, all of the pumps say up to 10% ethanol so your kinda at the mercy
of the refiner/supplier. I did find the primer hose was full of fuel
at a low point. I eliminated the low point where fuel could collect.
I'll see if this helps or not, it might have been preventing the carb
bowl from venting properly back to the hole in the center of the
primer bulb.

On Fri, 28 Jan 2011 21:30:59 -0800 (PST), oldjag
wrote:

On Jan 28, 9:54Â*am, Dave__67 wrote:
On Jan 28, 1:05Â*am, oldjag wrote:



Well it didn't happen yet, but a neighbor brought over her 2003
Troybilt 8526 so I could see why it stalls after running for 5
minutes. Â*Pulled off plastic cover shroud to work on the carb.
Noticed that the plastic shroud was molded with (3) bosses for
retention with extended head bolt studs, but only (2) head bolts were
headed with studs. Â*Why you may ask??, well at some point the mfr
added an 120V electric start option and the standard Tecumseh starter
switch/receptacle combo has the cord leaving the housing directly over
a head bolt, leaving no room for a "stud" headed capscrew for the
third boss. Â*Only problem is the plastic boss is still molded into the
cover and when bolted down with the two remaining head studs, it
tightly pinches the 120V cable going to the starter against a hot
cylinder head capscrew. Â*Only easy fix I see is to trim the cover boss
to clear the 120V cable as it exits the starter switch. Â*If you have
one of these take a look before you get zapped or at least use a GFI
outlet. Â*Think I'll email a photo to Troybilt/MTD. Â*By the way the
carb is a typical post '97 EPAised non-adjustable piece of crap. Â*How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

They are trading one type of emissions (HC) Â*for another (NOx).
If it's lean now wait till they try running it on E10.

Was the fuel vent in the cap plugged?

Dave

The vent is probably clear, I ran a 1/2 pint or so of fuel out of the
fuel hose at the carb to see if there was any restriction, kink vent
issue etc. BTW around here it's hard to know if your getting E10 or
not, all of the pumps say up to 10% ethanol so your kinda at the mercy
of the refiner/supplier. I did find the primer hose was full of fuel
at a low point. I eliminated the low point where fuel could collect.
I'll see if this helps or not, it might have been preventing the carb
bowl from venting properly back to the hole in the center of the
primer bulb.
If you have Shell stations around their premium is ethanol free, thei
regular up to E10, and the midgrade somewhere between as it is a mix
of the 2. I run Shell Ultra in my lawnmower and blower.

On Jan 29, 9:57*am, wrote:
On Fri, 28 Jan 2011 21:30:59 -0800 (PST), oldjag





wrote:
On Jan 28, 9:54*am, Dave__67 wrote:
On Jan 28, 1:05*am, oldjag wrote:

Well it didn't happen yet, but a neighbor brought over her 2003
Troybilt 8526 so I could see why it stalls after running for 5
minutes. *Pulled off plastic cover shroud to work on the carb.
Noticed that the plastic shroud was molded with (3) bosses for
retention with extended head bolt studs, but only (2) head bolts were
headed with studs. *Why you may ask??, well at some point the mfr
added an 120V electric start option and the standard Tecumseh starter
switch/receptacle combo has the cord leaving the housing directly over
a head bolt, leaving no room for a "stud" headed capscrew for the
third boss. *Only problem is the plastic boss is still molded into the
cover and when bolted down with the two remaining head studs, it
tightly pinches the 120V cable going to the starter against a hot
cylinder head capscrew. *Only easy fix I see is to trim the cover boss
to clear the 120V cable as it exits the starter switch. *If you have
one of these take a look before you get zapped or at least use a GFI
outlet. *Think I'll email a photo to Troybilt/MTD. *By the way the
carb is a typical post '97 EPAised non-adjustable piece of crap. *How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

They are trading one type of emissions (HC) *for another (NOx).
If it's lean now wait till they try running it on E10.

Was the fuel vent in the cap plugged?

Dave

The vent is probably clear, I ran a 1/2 pint or so of fuel out of the
fuel hose at the carb to see if there was any restriction, kink vent
issue etc. BTW around here it's hard to know if your getting E10 or
not, all of the pumps say up to 10% ethanol so your kinda at the mercy
of the refiner/supplier. *I did find the primer hose was full of fuel
at a low point. *I eliminated the low point where fuel could collect.
I'll see if this helps or not, it might have been preventing the carb
bowl from venting properly back to the hole in the center of the
primer bulb.

*If you have Shell stations around their premium is ethanol free, thei
regular up to E10, and the midgrade somewhere between as it is a mix
of the 2. I run Shell Ultra in my lawnmower and blower.- Hide quoted text -

- Show quoted text -

Depends on what state you're in. It's full alcohol blend on all three
available grades of any brand from Colorado to the middle of Nebraska,
then you can finally get uncontaminated gas on mid-grade through most
of IL and into IN. And they've upped the allowable to 20% now. How
that's going to work with older equipment is anyone's guess, mine
would be "poorly". I lose at least 10-15% mileage using 10%
contaminated gas as it is.

Stan

oldjag wrote:

How
can an engine that's missfiring because it's so lean make less
emissions than a correctly adjusted carb??

Your engine isn't "missfiring because it's so lean"

To answer your question about emissions:

Your talking about a one cylinder engine that is designed so that
if it misfires because the mixture is too lean
the engine simply quits running.
The carb is designed so that if the mixture is too lean
a single misfire will make it even more lean and thus
it will never recover from a single misfire.

If it misfires and keeps running then the problem is mechanical,
or electrical
or maybe even a little water mixed in with the gas
or the misfire is caused by a rich mixture

-jim