On Sunday 24 October 2004 7:28 pm in rec.boats Mr Wizzard wrote:

Surely someone must have some insight to this total mystery ??
I've been working on small engines, and specifically 2-strokes
for a long-long times, so this unsolved mystery has been having
a huge inpact on my life (and my shop, my time, and everything else).

Back to basics, you need:-
a) Fuel in at the correct fuel/air mixture
Check the carb and the inlet port. Some inlets
have reed valves. Do you get equal suction on
both cylinders.
b) Initial compression in the crankcase
This is the one that people forget - 2 stroke
engines must have crankcase compression. Check
for gaskets, seals, and broken reed valves.
If in doubt replace the reed valve, they do
tend to wear out and not seal.
c) Transfer to the top - I have never seen a blocked
transfer port but some idiot may have fitted the
wrong piston or fitted the piston the wrong way.
d) Final compression
Measure this with a compression tester
e) A good spark at the right time.
Check the timing. Use a new plug, lay it against
the block and check for a good fat spark at the
electodes before fitting.

In my experience most obscure 2 stroke problems are due
to some kind of crankcase leak, but check all of the
above before tearing down the engine.

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"Mr Wizzard" wrote in message news:f2Fed.415363$mD.411619@attbi_s02...
Got an old Monkey Wards Sea King .7.5 by Chrysler, and I am stumped.
It won't run on the bottom cylinder, not matter what I do. So far, I've :

changed the head, head gasket, coil, converted to electronic ignition,
went over the carb (twice), two new sets of plugs, looked at the reed
valves, and it STILL won't run regularly on that bottom cylinder. Runs
fine on the top cylinder, and every now and then you hear I occasionally
hear it pop and shutter, and hear it kick in, but for the most part, the
bottom cylinder won't run. Plug just black, sometime fluffy black,
sometime wet black. I even looked at the fuel pump diaphragm
under a magnifier glass, and it too looks fine. So what the heck
could I be missing here? Compression is at 150 Lbs. I just don't
get it. The only thing I can think of is the bottom crankcase seal
is bad, and I'm sucking in air or water or something. I even took
off the exhaust manifold plate to make sure the exhaust port wasn't
plugged. Peeked in the exhaust port, and the edge of the piston
looks fine. Surely someone have the missing clue, help!!

Thanks !


it sounds very much like a bad bottom crank seal. if you have good
spark and good compression and the carb is clean you are only left
with bad reeds or bad crankcase sealing. can you still buy parts for
that bad boy?

"BenC" wrote in message
om...
"Mr Wizzard" wrote in message
news:f2Fed.415363$mD.411619@attbi_s02...
Got an old Monkey Wards Sea King .7.5 by Chrysler, and I am stumped.
It won't run on the bottom cylinder, not matter what I do. So far, I've
:

changed the head, head gasket, coil, converted to electronic ignition,
went over the carb (twice), two new sets of plugs, looked at the reed
valves, and it STILL won't run regularly on that bottom cylinder. Runs
fine on the top cylinder, and every now and then you hear I occasionally
hear it pop and shutter, and hear it kick in, but for the most part, the
bottom cylinder won't run. Plug just black, sometime fluffy black,
sometime wet black. I even looked at the fuel pump diaphragm
under a magnifier glass, and it too looks fine. So what the heck
could I be missing here? Compression is at 150 Lbs. I just don't
get it. The only thing I can think of is the bottom crankcase seal
is bad, and I'm sucking in air or water or something. I even took
off the exhaust manifold plate to make sure the exhaust port wasn't
plugged. Peeked in the exhaust port, and the edge of the piston
looks fine. Surely someone have the missing clue, help!!

Thanks !


it sounds very much like a bad bottom crank seal. if you have good
spark and good compression and the carb is clean you are only left
with bad reeds or bad crankcase sealing. can you still buy parts for
that bad boy?

Ah, thats what I was afraid of. So lets talk about this - you seem to
seasoned, and knowledgable about this. Compression *is* good,
yeah. As I said, I questioned water leak at water jacket, so I went
and got a good used head, wet-sanded it on a 1/4" sheet of coffee
table glass, got that baby "aircraft grade" FLAT, torqued the head
and new head gasket to 70 in-lbs first, then same pattern at 130 in/lbs.
"some" (limited parts) are available. So.... This bottom crank seal....
What exactally do you suspect is happening? Water/air getting "in",
or fuel charge getting "out" ?? An d the reed valves..., they seem
perfect (accourding to how the service manual says to check them).
Service manual says MAX .005 in "lift" (distance the pedals are up
from the reed box). This engine has 2 pedals for each cylinder,
and on the bad hole, they were well within the limits. I would think
that for reeds to be causing this, they would REALLY have to be
obvious miss allignment, damage to the reeds for this cylinder, right?
So I come back to either the bottom seal, "or" still some oddaty
with the carb. Since any liquid coming out of the carb would fall
rignt down into the crankcase for the bottom cylinder by virtue of
the physical design of the reed box etc. So I'm wondering, is it
possible that raw fuel spray is hitting the reed box, and the liquid
part goes downstairs, while the upstairs takes the nice vaporized
part of the fuel mixture ? Or am I reading too much into that?
One part of me says that if the mixure was *that* rich/wet (due
to some unseen carb problem), then the top cylinder would'nt
be running as well as it does. (and it does run amazingly well).
Its just that sometime wet, black wet, fluffy-black, and combo
(like its running way too rich). But you'd get that over time on
a cylinder that wasn't firing, or able to maintain combustion. So
how common is the bottom crank seal to fail? Failure mode ?

many many thanks! - I'm totally fustrated here.

"Mr Wizzard" wrote in message
news:f2Fed.415363$mD.411619@attbi_s02...


Hey all! - just thought of a bit of information that I forgot to
add to all of this (which speaks to this lower crank seal bit).
Remember I said I had the reed box out a coupla times to
cheak/re-check, and in on post, I did say that I took out the
fuel pump diaphraghm to check it, right? - well, there is
something that I noticed that I thought was "odd", but just
didn't think too much about it. And this was the "black
deposit/stains in the lower crankcase. Mainly the well that
the fuel pump diaphraghm fits over. And looking into where
the reed box fits into, I can see a "little" into the lower crank
case. In both of these areas, I did see "blackish carbony
staining", more so in the little recess well on the side of the
lower crankcase for the fuel pump. To have "that" much
black carbon deposits/staining, there would HAVE to be
exhaust gases getting it, and circulating around this crank
case, right? I mean, I know that the fuel charge can cause
a light brown staining on crankcase components, expecially
around the scavanging ports and all, but "black" ?? So my
thoughts are this: (try to envision this). "IF", the lower
crankcase seal WAS badly leaking, the area BELOW the
crankshaft seal (free space in the intermeadiate housing)
IS positively charged with semi-presurized exhaust gas,
right? You have positive exhaust gas pressure in the open
area in the leg housing, because on these old motors (at
least this one), the "water ****er" holes are just that - "holes"
or slots in the housing (unlike the newer engines that tap
off of the water jacket up on the exhaust cover plate etc.)
So!.... if the open area in the intermeadiate housing below
the lower crankshaft seal is slightly presurized like this, AND
smokey/sooty as hell (like this engine appears to be running),
even the slightest vacuum in the crankcase (upward piston
stroke), coupled with an already smokey/sooty presurized
lower area on the other side of the seal, a badly leaking
lower crank seal would SURELY be letting smokey/sooty
gas INto the lower crankcase, explaining the black staining
in the areas of hte lower crankcase that I can see, PLUS
all of that wet black/fluffy black on the plug after just a few
minutes of run time - the upper cylinder is compressing,
and trying to ignite a charge that is already re-charged
with exhaust gas that us excaping into the crankcase.
So yeah, I guess I just talked my way thru this, and it all
makes perfect sense now. Dam, so got decisions to make.
Eat the $100, or bust out the cutting torch and get in heavy
iron worker mode. Thanks all for helping me thru this.







Got an old Monkey Wards Sea King .7.5 by Chrysler, and I am stumped.
It won't run on the bottom cylinder, not matter what I do. So far, I've :

changed the head, head gasket, coil, converted to electronic ignition,
went over the carb (twice), two new sets of plugs, looked at the reed
valves, and it STILL won't run regularly on that bottom cylinder. Runs
fine on the top cylinder, and every now and then you hear I occasionally
hear it pop and shutter, and hear it kick in, but for the most part, the
bottom cylinder won't run. Plug just black, sometime fluffy black,
sometime wet black. I even looked at the fuel pump diaphragm
under a magnifier glass, and it too looks fine. So what the heck
could I be missing here? Compression is at 150 Lbs. I just don't
get it. The only thing I can think of is the bottom crankcase seal
is bad, and I'm sucking in air or water or something. I even took
off the exhaust manifold plate to make sure the exhaust port wasn't
plugged. Peeked in the exhaust port, and the edge of the piston
looks fine. Surely someone have the missing clue, help!!

Thanks !

On Sun, 24 Oct 2004 20:04:59 GMT, "Mr Wizzard"
wrote:

~~ snippage ~~

makes perfect sense now. Dam, so got decisions to make.
Eat the $100, or bust out the cutting torch and get in heavy
iron worker mode.

mmmmmmmmmmheavyironworkermodemmmmmmmmmmm :)

Later,

Tom

"Beware the one legged man in a butt
kicking contest - he is there for a
reason."

Wun Hung Lo - date unknown

"Short Wave Sportfishing" wrote in message
news
On Sun, 24 Oct 2004 20:04:59 GMT, "Mr Wizzard"
wrote:

~~ snippage ~~

makes perfect sense now. Dam, so got decisions to make.
Eat the $100, or bust out the cutting torch and get in heavy
iron worker mode.

mmmmmmmmmmheavyironworkermodemmmmmmmmmmm :)

Do you, ahhh "Tig Weld" ? (in that: Do you, ah Yahoo voice)
I recently parted with my Miller Thunderbolt for one of these
new solid-state Thermal Arc STW-185, and I love it. (for TIG)
Regular DC arc mode takes some getting used to, and of course,
gone are the days of straight A/C sine wave welding with 7014,
or 6013, but its Ok. And only 40 Lbs, and small as a cracker
box. Neighbot has my Miller Thunderbold 300A A/C welder,
so its not too far away when I want to relieve a little stress and
but up 5 Lbs of rod in them late evening "who can run the nicer
bead" contest(s). hehe

So final update! Decided to see if I could the powerhead
seperated., and sure enough, came apart pretty easily.
Sure 'nuff, crankshaft seal toast. All "oozing" muck and such.
There is an intermeadiate seal that kinda protects the lower
seal, and that looked like it failed too, and there is a watery
grey ooze all up around the crankshaft seal, and the part of the
lip of the crankshaft seal itself is oozing some bubbly **** out
of the crankcase (which I have to assume is trapped something).
close up pics to follow, but there you have it folks, mystery solved!







Later,

Tom

"Beware the one legged man in a butt
kicking contest - he is there for a
reason."

Wun Hung Lo - date unknown

On Sun, 24 Oct 2004 20:52:11 GMT, "Mr Wizzard"
wrote:


"Short Wave Sportfishing" wrote in message
news
On Sun, 24 Oct 2004 20:04:59 GMT, "Mr Wizzard"
wrote:

~~ snippage ~~

makes perfect sense now. Dam, so got decisions to make.
Eat the $100, or bust out the cutting torch and get in heavy
iron worker mode.

mmmmmmmmmmheavyironworkermodemmmmmmmmmmm :)

Do you, ahhh "Tig Weld" ? (in that: Do you, ah Yahoo voice)
I recently parted with my Miller Thunderbolt for one of these
new solid-state Thermal Arc STW-185, and I love it. (for TIG)

Actually, I don't - I don't have the patience for it. I have an Esab
453CV which I could build a freakin' ship with if I wanted to. I
picked it up at an auction for cheap money - it was the last item
auctioned and nobody had any money left. :)

I had the Miller Dialarc 250 which I sold to one of the local farmers.
I actually perfer the Esab, but man, I could build aircraft carriers
with the damn thing.


Regular DC arc mode takes some getting used to, and of course,
gone are the days of straight A/C sine wave welding with 7014,
or 6013, but its Ok. And only 40 Lbs, and small as a cracker
box. Neighbot has my Miller Thunderbold 300A A/C welder,
so its not too far away when I want to relieve a little stress and
but up 5 Lbs of rod in them late evening "who can run the nicer
bead" contest(s). hehe

So final update! Decided to see if I could the powerhead
seperated., and sure enough, came apart pretty easily.
Sure 'nuff, crankshaft seal toast. All "oozing" muck and such.
There is an intermeadiate seal that kinda protects the lower
seal, and that looked like it failed too, and there is a watery
grey ooze all up around the crankshaft seal, and the part of the
lip of the crankshaft seal itself is oozing some bubbly **** out
of the crankcase (which I have to assume is trapped something).
close up pics to follow, but there you have it folks, mystery solved!

YAY!!

Good luck with it.

All the best,

Tom
--------------

"What the hell's the deal with this newsgroup...
is there a computer terminal in the day room of
some looney bin somewhere?"

Bilgeman - circa 2004

On Sunday 24 October 2004 9:52 pm in rec.boats Mr Wizzard wrote:

So final update! Decided to see if I could the powerhead
seperated., and sure enough, came apart pretty easily.
Sure 'nuff, crankshaft seal toast. All "oozing" muck and such.
There is an intermeadiate seal that kinda protects the lower
seal, and that looked like it failed too, and there is a watery
grey ooze all up around the crankshaft seal, and the part of the
lip of the crankshaft seal itself is oozing some bubbly **** out
of the crankcase (which I have to assume is trapped something).
close up pics to follow, but there you have it folks, mystery solved!

Why did that seal fail ?
Check for side play in the bearings allowing the shaft to
rattle around in the seals.
Probably a good idea to change the bearings while you have
it apart anyway.


--
My real address is crn (at) netunix (dot) com
WARNING all messages containing attachments or html will be silently
deleted. Send only plain text.

"Chris Newport" wrote in message
news:1799302.emnxexnZYx@callisto...
On Sunday 24 October 2004 9:52 pm in rec.boats Mr Wizzard wrote:

So final update! Decided to see if I could the powerhead
seperated., and sure enough, came apart pretty easily.
Sure 'nuff, crankshaft seal toast. All "oozing" muck and such.
There is an intermeadiate seal that kinda protects the lower
seal, and that looked like it failed too, and there is a watery
grey ooze all up around the crankshaft seal, and the part of the
lip of the crankshaft seal itself is oozing some bubbly **** out
of the crankcase (which I have to assume is trapped something).
close up pics to follow, but there you have it folks, mystery solved!

Why did that seal fail ?

Dunno, looks like it got gooey, and mushy. Easters in the
oil maybe? ethenol in the gas ? salt? (although I'da figured
that salt would make rubber hard). But who knows. The
thing is 25 years old or so.



Check for side play in the bearings allowing the shaft to
rattle around in the seals.

I did, seems fine.


Probably a good idea to change the bearings while you have
it apart anyway.

Well, it all gets down to if I can get bearings/seals from Force.
Anyone have a good source for old Force parts, or a favorite
Force dealer ? I have this one guy I been working with in
Boston or someplace, but wondering if there are aothers.

Thanks!





--
My real address is crn (at) netunix (dot) com
WARNING all messages containing attachments or html will be silently
deleted. Send only plain text.

"Chris Newport" wrote in message
news:1799302.emnxexnZYx@callisto...
On Sunday 24 October 2004 9:52 pm in rec.boats Mr Wizzard wrote:

So final update! Decided to see if I could the powerhead
seperated., and sure enough, came apart pretty easily.
Sure 'nuff, crankshaft seal toast. All "oozing" muck and such.
There is an intermeadiate seal that kinda protects the lower
seal, and that looked like it failed too, and there is a watery
grey ooze all up around the crankshaft seal, and the part of the
lip of the crankshaft seal itself is oozing some bubbly **** out
of the crankcase (which I have to assume is trapped something).
close up pics to follow, but there you have it folks, mystery solved!

Why did that seal fail ?

Actually, I take back what I just said in an adjacent post.
There is at least 10 thousands play in the crankshaft. Further,
it looks like (from waht I can see), the crankshaft is turning
inside what appears to be the innter bearing race. Haven't
splt the case yet, but if this is a true ball bearing, this is bad news,
means that hte ball bearing may be frozen. However, it might
be a just a bronze sleeve, I'll know more when I split the case.
(can't inagine a bronze sleeve bearing instead of a ball bearing).
Anyone know ?