Time For Another Dumb Question

Just what exactly does a "choke" do?

"Maxwell Smart" <[email protected]> wrote in message
news:bMuLa.172534$eJ2.145682@fed1read07...
> Just what exactly does a "choke" do?

A choke is a remote-controllable plate that covers up part of the air intake
on a carburetor. By restricting the air going into the carburetor, it makes
the air/fuel mixture richer. In older cars, there was a choke knob you could
pull out from the dash to control the choke itself. More modern carbureted
engines control the choke automatically. A choke's purpose is to enrichen
the air-fuel mixture, especially when the engine is cold, so it can start
easier and run a little better... due to the richer air-fuel mixutre...
until the engine is more fully warmed up.

Jerry

--
Jerry Bransford
KC6TAY, PP-ASEL
The Zen Hotdog, make me one with everything!
See the Geezer Jeep at
http://members.cox.net/jerrypb/

Thanks for the explanation. My question isn't related to cars or trucks but I figured
someone here would know. Actually it has to do with chainsaws but I do use my truck to get
where I am going to use the saw . The problem I have is vapor lock and no one has any
good idea how to get it started when that happens. I did try choking it a lot (with the
knob like you referenced) and it finally started. I should mention that this only happens
when the weather is really hot (like it is now). Sorry about the off topic item - I never
actually looked to see if there was a "chainsaw" group.


"Jerry Bransford" <[email protected]> wrote in message
news:MkvLa.109290$hd6.37479@fed1read05...
>
> "Maxwell Smart" <[email protected]> wrote in message
> news:bMuLa.172534$eJ2.145682@fed1read07...
> > Just what exactly does a "choke" do?
>
> A choke is a remote-controllable plate that covers up part of the air intake
> on a carburetor. By restricting the air going into the carburetor, it makes
> the air/fuel mixture richer. In older cars, there was a choke knob you could
> pull out from the dash to control the choke itself. More modern carbureted
> engines control the choke automatically. A choke's purpose is to enrichen
> the air-fuel mixture, especially when the engine is cold, so it can start
> easier and run a little better... due to the richer air-fuel mixutre...
> until the engine is more fully warmed up.
>
> Jerry
>
> --
> Jerry Bransford
> KC6TAY, PP-ASEL
> The Zen Hotdog, make me one with everything!
> See the Geezer Jeep at
> http://members.cox.net/jerrypb/
>
>

LOL. I have a lot more trouble starting my chainsaw than the Jeep as
well, especially hot. The problem I see in hot weather is that the
gas gets too hot and forms vapor in the lines when I shut it down hot.
When that happens, the fuel pump - which is a simple suction thing
anyway - can't pull gas. One the newer one with a primer bulb, I can
usually pop that a few times and break the lock but the older one is a
hassle. I finally found a place that had a replacement fuel cap with
a built-in pump buld to pressurize the tank a little to get it going.

On Sun, 29 Jun 2003 16:30:22 UTC "Maxwell Smart" <[email protected]>
wrote:

> Thanks for the explanation. My question isn't related to cars or trucks but I figured
> someone here would know. Actually it has to do with chainsaws but I do use my truck to get
> where I am going to use the saw . The problem I have is vapor lock and no one has any
> good idea how to get it started when that happens. I did try choking it a lot (with the
> knob like you referenced) and it finally started. I should mention that this only happens
> when the weather is really hot (like it is now). Sorry about the off topic item - I never
> actually looked to see if there was a "chainsaw" group.
>
>
> "Jerry Bransford" <[email protected]> wrote in message
> news:MkvLa.109290$hd6.37479@fed1read05...
> >
> > "Maxwell Smart" <[email protected]> wrote in message
> > news:bMuLa.172534$eJ2.145682@fed1read07...
> > > Just what exactly does a "choke" do?
> >
> > A choke is a remote-controllable plate that covers up part of the air intake
> > on a carburetor. By restricting the air going into the carburetor, it makes
> > the air/fuel mixture richer. In older cars, there was a choke knob you could
> > pull out from the dash to control the choke itself. More modern carbureted
> > engines control the choke automatically. A choke's purpose is to enrichen
> > the air-fuel mixture, especially when the engine is cold, so it can start
> > easier and run a little better... due to the richer air-fuel mixutre...
> > until the engine is more fully warmed up.
> >
> > Jerry
> >
> > --
> > Jerry Bransford
> > KC6TAY, PP-ASEL
> > The Zen Hotdog, make me one with everything!
> > See the Geezer Jeep at
> > http://members.cox.net/jerrypb/
> >
> >
>
>


--
Will Honea <[email protected]>

"Will Honea" <[email protected]> wrote in message
news:[email protected]...
> LOL. I have a lot more trouble starting my chainsaw than the Jeep as
> well, especially hot. The problem I see in hot weather is that the
> gas gets too hot and forms vapor in the lines when I shut it down hot.
> When that happens, the fuel pump - which is a simple suction thing
> anyway - can't pull gas. One the newer one with a primer bulb, I can
> usually pop that a few times and break the lock but the older one is a
> hassle. I finally found a place that had a replacement fuel cap with
> a built-in pump buld to pressurize the tank a little to get it going.


Oh wow it really gets me so ****ed off! It starts up fine the first time. If I stop to
refuel that's no problem. But if I stop to clear the stuff I have cut or move to a new
site, FORGET it! I am cutting branches on my Adopt A Road project. My only solution is to
let it idle while I do my clean up or move it to a new location (i.e. riding in the truck)
with it idling (not a good idea). I have a Poulon (sp?) with the little bulb on it. I can
actually hear the fuel sizzling when I try a restart. As of late I have taken to putting
it back in its duffle bag with a damp towel over the engine (there's no shade except for
my truck). That's why I asked about the choke. I choked the sh*t out of it (i.e. pull the
knob out and pull the rope; about 25 times: normal is 3 or 4) and it started.

My right arm is starting to look like Popeye's!

Instead of choking, would it be better to pump the primer bulb about 10 times? Actually I
never use that bulb because it's so easy to flood the unit. The dealer told me that he'd
like to spend 30 minutes reaming out the morons who design some of the features on these
saws. I notice the new Poulon 20" has no bulb.

Can you guys place some ice on or place an ice-pack on the fuel line to get
rid of the vapor lock?

--
--
Jerry Bransford
KC6TAY, PP-ASEL
The Zen Hotdog, make me one with everything!
See the Geezer Jeep at
http://members.cox.net/jerrypb/

"Maxwell Smart" <[email protected]> wrote in message
news:8lHLa.172597$eJ2.83994@fed1read07...
>
> "Will Honea" <[email protected]> wrote in message
> news:[email protected]...
> > LOL. I have a lot more trouble starting my chainsaw than the Jeep as
> > well, especially hot. The problem I see in hot weather is that the
> > gas gets too hot and forms vapor in the lines when I shut it down hot.
> > When that happens, the fuel pump - which is a simple suction thing
> > anyway - can't pull gas. One the newer one with a primer bulb, I can
> > usually pop that a few times and break the lock but the older one is a
> > hassle. I finally found a place that had a replacement fuel cap with
> > a built-in pump buld to pressurize the tank a little to get it going.
>
>
> Oh wow it really gets me so ****ed off! It starts up fine the first time.
If I stop to
> refuel that's no problem. But if I stop to clear the stuff I have cut or
move to a new
> site, FORGET it! I am cutting branches on my Adopt A Road project. My only
solution is to
> let it idle while I do my clean up or move it to a new location (i.e.
riding in the truck)
> with it idling (not a good idea). I have a Poulon (sp?) with the little
bulb on it. I can
> actually hear the fuel sizzling when I try a restart. As of late I have
taken to putting
> it back in its duffle bag with a damp towel over the engine (there's no
shade except for
> my truck). That's why I asked about the choke. I choked the sh*t out of it
(i.e. pull the
> knob out and pull the rope; about 25 times: normal is 3 or 4) and it
started.
>
> My right arm is starting to look like Popeye's!
>
> Instead of choking, would it be better to pump the primer bulb about 10
times? Actually I
> never use that bulb because it's so easy to flood the unit. The dealer
told me that he'd
> like to spend 30 minutes reaming out the morons who design some of the
features on these
> saws. I notice the new Poulon 20" has no bulb.
>
>

The fuel line is tiny; I mean smaller than a hose on a water pik! And it is hidden beneath
the cover. That's why I resorted to a wet towel and keeping it inside the duffle bag. An
ice pack wouldn't last long in the heat here; I use them in my ice chest and they wither
very quickly. I am thinking about adding some crushed ice to my cooler; then the ice packs
will last longer. Of course a sane, rational person would merely wait until fall when the
weather is cooler...

"Jerry Bransford" <[email protected]> wrote in message
news:SkKLa.110295$hd6.54551@fed1read05...
> Can you guys place some ice on or place an ice-pack on the fuel line to get
> rid of the vapor lock?
>
> --
> --
> Jerry Bransford
> KC6TAY, PP-ASEL
> The Zen Hotdog, make me one with everything!
> See the Geezer Jeep at
> http://members.cox.net/jerrypb/
>
> "Maxwell Smart" <[email protected]> wrote in message
> news:8lHLa.172597$eJ2.83994@fed1read07...
> >
> > "Will Honea" <[email protected]> wrote in message
> > news:[email protected]...
> > > LOL. I have a lot more trouble starting my chainsaw than the Jeep as
> > > well, especially hot. The problem I see in hot weather is that the
> > > gas gets too hot and forms vapor in the lines when I shut it down hot.
> > > When that happens, the fuel pump - which is a simple suction thing
> > > anyway - can't pull gas. One the newer one with a primer bulb, I can
> > > usually pop that a few times and break the lock but the older one is a
> > > hassle. I finally found a place that had a replacement fuel cap with
> > > a built-in pump buld to pressurize the tank a little to get it going.
> >
> >
> > Oh wow it really gets me so ****ed off! It starts up fine the first time.
> If I stop to
> > refuel that's no problem. But if I stop to clear the stuff I have cut or
> move to a new
> > site, FORGET it! I am cutting branches on my Adopt A Road project. My only
> solution is to
> > let it idle while I do my clean up or move it to a new location (i.e.
> riding in the truck)
> > with it idling (not a good idea). I have a Poulon (sp?) with the little
> bulb on it. I can
> > actually hear the fuel sizzling when I try a restart. As of late I have
> taken to putting
> > it back in its duffle bag with a damp towel over the engine (there's no
> shade except for
> > my truck). That's why I asked about the choke. I choked the sh*t out of it
> (i.e. pull the
> > knob out and pull the rope; about 25 times: normal is 3 or 4) and it
> started.
> >
> > My right arm is starting to look like Popeye's!
> >
> > Instead of choking, would it be better to pump the primer bulb about 10
> times? Actually I
> > never use that bulb because it's so easy to flood the unit. The dealer
> told me that he'd
> > like to spend 30 minutes reaming out the morons who design some of the
> features on these
> > saws. I notice the new Poulon 20" has no bulb.
> >
> >
>
>

Jerry Bransford wrote:
> Can you guys place some ice on or place an ice-pack on the fuel line to get
> rid of the vapor lock?
>

[rest of posting MIME'd and gone]

CO2 fire extinguisher has been known to work.

"Lon Stowell" <[email protected]> wrote in message news:[email protected]...
> Jerry Bransford wrote:
> > Can you guys place some ice on or place an ice-pack on the fuel line to get
> > rid of the vapor lock?
> >
>
> [rest of posting MIME'd and gone]
>
> CO2 fire extinguisher has been known to work.
>
>

actually I was thinking about what jerry said and I seem to recall seeing little ice packs
in a flexible package-type affair instead of the bricks like I use in my cooler. Maybe a
couple of those wrapped inside an old sock or something would keep the engine & fuel line
cooler.

Jerry, this is one of those "engeneering marvels" similar to the carbs
on old Fords. The tank is so close to the engine that the whole fuel
supply gets hot, then the little bitty fuel feed tube gets even hotter
and bubbles. I've been tempted to try the solution an old geezer
(even older than I am) gave me for a Volkwagon 1200 cc bug years back.
His instructions were:

"If it vapor locks after you shut it down, try pouring water over the
fuel pump. If you don't have water, **** on it".

Worked every time for the bug, maybe it would work on the saw. I feel
like trying it every now and then anyway.

BTW, for the OP: My McCollough is also a LOT easier to start if I'll
let it idle for 2-3 minutes before I shut it down.

On Sun, 29 Jun 2003 23:09:33 UTC "Jerry Bransford" <[email protected]>
wrote:

> Can you guys place some ice on or place an ice-pack on the fuel line to get
> rid of the vapor lock?
>


--
Will Honea <[email protected]>

"Will Honea" <[email protected]> wrote in message
news:[email protected]...
> Jerry, this is one of those "engeneering marvels" similar to the carbs
> on old Fords. The tank is so close to the engine that the whole fuel
> supply gets hot, then the little bitty fuel feed tube gets even hotter
> and bubbles. I've been tempted to try the solution an old geezer
> (even older than I am) gave me for a Volkwagon 1200 cc bug years back.
> His instructions were:
>
> "If it vapor locks after you shut it down, try pouring water over the
> fuel pump. If you don't have water, **** on it".
>
> Worked every time for the bug, maybe it would work on the saw. I feel
> like trying it every now and then anyway.
>
> BTW, for the OP: My McCollough is also a LOT easier to start if I'll
> let it idle for 2-3 minutes before I shut it down.

LOL where is the fuel pump? I don't think it has one... Like I posted before, the fuel
line is really small. I had a Mac before I got the Poulon. The first Mac was ok except it
leaked around the oil filler. My stupidity was bitching to K Mart and they exchanged it
for another one. It ran ok for about 4 months and then turned into the hardest starting
dog I ever saw. I almost threw it down a mine shaft more than once. Strangely every time I
got that ****ed, it would finally start (this isn't a vapor lock problem. it just is a
hard starting pos). I finally bought the Poulon and have cut millions of miles of brush
for the FS (at a pay rate of 0, I might add) and the only thing I ever replaced besides
chains and bars was a clutch and a handle - the latter broke when it fell off the back of
my truck. My Mac is still sitting here at the house. Every so often when I am feeling just
fine, I got out and try to start it. that changes my day for sure. No wonder they went
bankrupt!

Maybe the 2-3 minutes idling keeps the line full of fuel? Mine sounds like sizzling bacon
when I have the vapor lock problem. Or it will start and race way up (rpms) and then just
die.