Which gap? Spark plug? Valves? Piston rings? or.... or.....

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Hustlin' Hank"
wrote in message
...


First.......put in a new plug. Just because it fires,
doesn't mean the
plug is good. I have seen engines run (poorly) with a bad
plug.

You say it has compression, but does it have enough. Just
because the
valve seats look good, doesn't mean the are closing all the
way. Check
the gap, should be approx. .04

Hank

On Wed, 05 May 2010 14:50:08 -0700, Oren wrote:

On Wed, 5 May 2010 17:53:42 +0000 (UTC), Jules Richardson
wrote:

(Although if it is a compression issue, I still don't get why it was
running last season and magically broke over the winter...)

One of the piston rings froze up?

Yep, I thought the same thing.

OR A valve is sticking open.

Before ripping it all apart, pour some kerosene or diesel in the
sparkplug hole. (bout a quarter cup) Put the plug back in finger
tight, without the plug wire attached. Turn the engine over by hand.
It will likely not turn all the way because of fluid lock when the
piston comes to the top. Leave it sit like that for a day. If a ring
is stuck, this may free it, as well as a stuck valve. You can always
open a cover on most engines to see the valve stems move. You can
always work them up and down with a plyers.

When you want to start it, remove the spark plug and spin it over to
blow out the remaining kerosene, clean the plug and reinstall it, and
try to start the engine.

Once you get it started, change the oil because the kerosene may have
diluted it.

If the kerosene is gone after one day, you definately have a leaking
piston ring.

--

I just reread your original message. Since you have the head off,
lower the piston and pour some kerosene on it. Work it up and down by
hand and leave it sit with the kero in the cylinder for a day.

YOU WROTE
Oh, I cleaned up the carb on the 11HP and tried it on the 10HP. It
will fire consistantly for maybe 4-5revs, then die, so not really any
better than the 10HP's own carb was. No different swapping the plug,
either. Magneto is unfortunately trashed on the 11HP, so I can't try
swapping that.

Did you know that you can take a propane torch, turn it on, (dont
light it), and let the propane enter the carburetor while it's
running. It should stay running because the propane is burning in the
engine. If it's the magneto, it still wont run. If the carb is at
fault, it should still run from the propane.

On May 5, 8:54�pm, "Stormin Mormon"
wrote:
Which gap? Spark plug? Valves? Piston rings? or.... or.....

--
Christopher A. Young

The valve clearance. Over time the valve seats wear and the gap
closes, not allowing the vlave to close completely. If the vlave
clearance is less than .04, the valves MUST be removed and ground down
to the proper clearance.

Hank

On Apr 30, 9:13*pm, "Stormin Mormon"
wrote:
Easy off oven cleaner is excellent for cleaning carbs.
Strips off gum and varnish. Rinse well, and dry before
reassembling. Best carb cleaner I've ever used.

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Jules Richardson" wrote
in ...

Hmm, I'll revisit that. I can pull it and strip it down in
less than 5
minutes these days :-) Don't think I have any carb cleaner,
although I do
have some brake parts cleaner - maybe that's asking for
trouble, though!
(I'm not sure how similar it is)

How can you give a suggestion like that? Caustic (many oven cleaners
have it) will eat die-cast (pot metal)! Moron, not Mormon!

When I took a small engine course, we learned that the
intake valve clearance is .010 and the exhaust is .020
inches. That from memory, and it's been a lot of years since
then.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Hustlin' Hank" wrote in message
...
On May 5, 8:54�pm, "Stormin Mormon"
wrote:
Which gap? Spark plug? Valves? Piston rings? or....
or.....

--
Christopher A. Young

The valve clearance. Over time the valve seats wear and the
gap
closes, not allowing the vlave to close completely. If the
vlave
clearance is less than .04, the valves MUST be removed and
ground down
to the proper clearance.

Hank

On May 6, 5:51*am, "Hustlin' Hank" wrote:
On May 5, 8:54 pm, "Stormin Mormon"

wrote:
Which gap? Spark plug? Valves? Piston rings? or.... or.....

--
Christopher A. Young

The valve clearance. Over time the valve seats wear and the gap
closes, not allowing the vlave to close completely. If the vlave
clearance is less than .04, the valves MUST be removed and ground down
to the proper clearance.

Hank

It was very apparent what you meant...some people need to be hit with
a 2X4!

How much time does it take to clean a carb, versus how long
to eat potmetal? As I suggested, rinse well and dry. As
someone else suggested, rinse promptly, and thoroughly.
People (like you) who abuse exclaimation points can be
helped!!!!!!

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bob Villa" wrote in message
...
On Apr 30, 9:13 pm, "Stormin Mormon"
wrote:
Easy off oven cleaner is excellent for cleaning carbs.
Strips off gum and varnish. Rinse well, and dry before
reassembling. Best carb cleaner I've ever used.


How can you give a suggestion like that? Caustic (many oven
cleaners
have it) will eat die-cast (pot metal)! Moron, not Mormon!

On May 6, 6:24*am, "Stormin Mormon"
wrote:
How much time does it take to clean a carb, versus how long
to eat potmetal? *As I suggested, rinse well and dry. As
someone else suggested, rinse promptly, and thoroughly.
People (like you) *who abuse exclaimation points can be
helped!!!!!!

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Bob Villa" wrote in message

...
On Apr 30, 9:13 pm, "Stormin Mormon"

wrote:
Easy off oven cleaner is excellent for cleaning carbs.
Strips off gum and varnish. Rinse well, and dry before
reassembling. Best carb cleaner I've ever used.

How can you give a suggestion like that? *Caustic (many oven
cleaners
have it) will eat die-cast (pot metal)! Moron, not Mormon!

What you kinda remember is the 10-20-30 rule. .010" for mag/fly, .
020" for points, .030" for spark plug! (don't want to disappoint!)
bob

Spark plug gap for BS engines is 0.035, so 0.040 isn't that
far off. Some idiots need to stop embarassing themselves
with clueless flames.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bob Villa" wrote in message
...
On May 6, 5:51 am, "Hustlin' Hank"
wrote:
On May 5, 8:54 pm, "Stormin Mormon"

wrote:
Which gap? Spark plug? Valves? Piston rings? or....
or.....

--
Christopher A. Young

The valve clearance. Over time the valve seats wear and
the gap
closes, not allowing the vlave to close completely. If the
vlave
clearance is less than .04, the valves MUST be removed and
ground down
to the proper clearance.

Hank

It was very apparent what you meant...some people need to be
hit with
a 2X4!

Stormin' Moron wrote:
Spark plug gap for BS engines is 0.035, so 0.040 isn't that
far off. Some idiots need to stop embarassing themselves
with clueless flames.

Now you're saying you were right comparing a spark gap with a valve
clearance gap...and you're NOT the idiot here!!!!!!!!!!
You have waaaay too much time here giving bad advice that you can't
keep straight in your head (age related).

Bob Villa

On Thu, 06 May 2010 03:51:19 -0700, Hustlin' Hank wrote:

On May 5, 8:54�pm, "Stormin Mormon"
wrote:
Which gap? Spark plug? Valves? Piston rings? or.... or.....

--
Christopher A. Young

The valve clearance. Over time the valve seats wear and the gap closes,
not allowing the vlave to close completely. If the vlave clearance is
less than .04, the valves MUST be removed and ground down to the proper
clearance.

Yeah, I'll check them. Visually they look good (i.e. seating evenly and
no other obvious major drama has occurred) but that's no guarantee that
they're not worn so much as to be inefficient.

I've found the allowed clearances for that engine - 0.005 to 0.007" on
the intake and 0.009 to 0.011" on the exhaust.

cheers

Jules

On Thu, 06 May 2010 03:06:48 -0500, mister_friendly wrote:
I just reread your original message. Since you have the head off, lower
the piston and pour some kerosene on it. Work it up and down by hand
and leave it sit with the kero in the cylinder for a day.

Yeah, I'll give that a go; as it's a horizontal cylinder I'll have to
pull the engine, or just stand the whole mower up on its butt :-) It
seems like a worthwhile test, though - I really don't like how loose that
piston is feeling compared to the "new" 11HP engine I got.

cheers

Jules

On Thu, 06 May 2010 12:58:07 -0400, Stormin Mormon wrote:

Spark plug gap for BS engines is 0.035, so 0.040 isn't that far off.

Just for the record, 0.030" for this B+S engine according to their
operating manual (just in case someone stumbles across this thread at a
later date! :-)

cheers

J.

On Wed, 05 May 2010 13:27:36 -0500, dpb wrote:
If you can use a thumb in the spark plug hole and keep it from blowing
by, it's a good chance it is that bad...

Hmm, well it fails that test (or passes it, depending on how you look at
it. I can keep my thumb there while it's turning over; I can feel it
compressing, but it's not so much that I can't keep my thumb in place.

I've only worked with big multi-cylinder engines before, so messing with
the small single-cylinder stuff is a bit of a (fun!) learning experience
- I'm not sure how good compression *should* be on such a small engine,
but it sounds like this engine doesn't exactly have a lot :-)

(unfortunately I do have a compression tester, but it's 4000 miles away,
which isn't much use right now! Maybe I should just cave and buy another
one...)

cheers

Jules

The small engines I've serviced. I've had to pull a
rectangular cover from the side of the motor, which exposes
the valve springs. The clearance is measured between the end
of the valve stem, and the push rod. Have to turn the crank
shaft so the lifting pressure is released. As the engine
warms up, the valve stems lengthen due to temperature. So,
there needs to be a gap, to compensate for the lengthening.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Jules Richardson" wrote
in message ...

The valve clearance. Over time the valve seats wear and
the gap closes,
not allowing the vlave to close completely. If the vlave
clearance is
less than .04, the valves MUST be removed and ground down
to the proper
clearance.

Yeah, I'll check them. Visually they look good (i.e. seating
evenly and
no other obvious major drama has occurred) but that's no
guarantee that
they're not worn so much as to be inefficient.

I've found the allowed clearances for that engine - 0.005 to
0.007" on
the intake and 0.009 to 0.011" on the exhaust.

cheers

Jules

http://www.harborfreight.com/flex-dr...ter-92697.html
Ten bucks. You can likely find a 20% off coupons, too.

As to piston rings loosening. I'd consider diesel or WD-40
which at least have some lubricating value.

Thanks for the correction: Spark plug gap .030 sounds right.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Jules Richardson" wrote
in message ...
On Wed, 05 May 2010 13:27:36 -0500, dpb wrote:
If you can use a thumb in the spark plug hole and keep it
from blowing
by, it's a good chance it is that bad...

Hmm, well it fails that test (or passes it, depending on how
you look at
it. I can keep my thumb there while it's turning over; I
can feel it
compressing, but it's not so much that I can't keep my thumb
in place.

I've only worked with big multi-cylinder engines before, so
messing with
the small single-cylinder stuff is a bit of a (fun!)
learning experience
- I'm not sure how good compression *should* be on such a
small engine,
but it sounds like this engine doesn't exactly have a lot
:-)

(unfortunately I do have a compression tester, but it's 4000
miles away,
which isn't much use right now! Maybe I should just cave and
buy another
one...)

cheers

Jules

On Fri, 07 May 2010 12:25:36 +0000, Jules Richardson wrote:

On Thu, 06 May 2010 03:06:48 -0500, mister_friendly wrote:
I just reread your original message. Since you have the head off,
lower the piston and pour some kerosene on it. Work it up and down by
hand and leave it sit with the kero in the cylinder for a day.

Yeah, I'll give that a go; as it's a horizontal cylinder I'll have to
pull the engine, or just stand the whole mower up on its butt :-) It
seems like a worthwhile test, though - I really don't like how loose
that piston is feeling compared to the "new" 11HP engine I got.

OK, now sitting there with a gas/oil mixture (about 75% gas, 25% oil) in
the bore - I'll see how that goes if I leave it overnight.

I checked the valve clearances - 0.005" on the inlet and 0.011" on the
exhaust, so those are within spec.

I got the 11HP engine running earlier, borrowing the magneto and spark
plug from the broken 10HP. That seems to rule those out as culprits on
the 10HP. I still can't definitely rule out carb issues, although it's
interesting that the 11HP ran with its carb, but that carb didn't get the
10HP going.

I've not checked the ignition timing yet as I didn't have a suitable
wrench for the 1-1/4" bolt on the flywheel, but I suppose I can always
compare the flywheel position on the 10HP at TDC relative to the 11HP.

cheers

Jules

On Fri, 07 May 2010 23:39:04 +0000, Jules Richardson wrote:

On Fri, 07 May 2010 12:25:36 +0000, Jules Richardson wrote:

On Thu, 06 May 2010 03:06:48 -0500, mister_friendly wrote:
I just reread your original message. Since you have the head off,
lower the piston and pour some kerosene on it. Work it up and down by
hand and leave it sit with the kero in the cylinder for a day.

Yeah, I'll give that a go; as it's a horizontal cylinder I'll have to
pull the engine, or just stand the whole mower up on its butt :-) It
seems like a worthwhile test, though - I really don't like how loose
that piston is feeling compared to the "new" 11HP engine I got.

OK, now sitting there with a gas/oil mixture (about 75% gas, 25% oil) in
the bore - I'll see how that goes if I leave it overnight.

And just as a final follow-up, that mix had all leaked through into the
crankcase by the following morning... (oh, and I cross-checked flywheel
position against the 11HP engine, and no problems there, so not sheared
key)

Sometime I'll pull the piston out and check the rings, but I'm not in too
much of a hurry now - I dropped the 11HP engine into the mower at the
weekend and then cut the grass, and it worked far better than the 10HP
ever had and didn't go through any more gas doing it.

I might try and fix that 10HP one day though (assuming it just needs new
rings rather than a re-bore) just to keep a spare around... or I might
find a use for another engine around the place.

cheers

Jules

On Tue, 11 May 2010 15:07:05 +0000 (UTC), Jules Richardson
wrote:

On Fri, 07 May 2010 23:39:04 +0000, Jules Richardson wrote:

On Fri, 07 May 2010 12:25:36 +0000, Jules Richardson wrote:

On Thu, 06 May 2010 03:06:48 -0500, mister_friendly wrote:
I just reread your original message. Since you have the head off,
lower the piston and pour some kerosene on it. Work it up and down by
hand and leave it sit with the kero in the cylinder for a day.

Yeah, I'll give that a go; as it's a horizontal cylinder I'll have to
pull the engine, or just stand the whole mower up on its butt :-) It
seems like a worthwhile test, though - I really don't like how loose
that piston is feeling compared to the "new" 11HP engine I got.

OK, now sitting there with a gas/oil mixture (about 75% gas, 25% oil) in
the bore - I'll see how that goes if I leave it overnight.

And just as a final follow-up, that mix had all leaked through into the
crankcase by the following morning... (oh, and I cross-checked flywheel
position against the 11HP engine, and no problems there, so not sheared
key)

Sometime I'll pull the piston out and check the rings, but I'm not in too
much of a hurry now - I dropped the 11HP engine into the mower at the
weekend and then cut the grass, and it worked far better than the 10HP
ever had and didn't go through any more gas doing it.

I might try and fix that 10HP one day though (assuming it just needs new
rings rather than a re-bore) just to keep a spare around... or I might
find a use for another engine around the place.

cheers

Jules

It is always (IMO) a good idea to hone the cylinder to remove any
glaze and assist the new rings in seating.