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Mr Wizzard October 24th 04 04:10 AM

Montgumrery Wards Chrysler Seak King 7.5 problem
 
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 !



Short Wave Sportfishing October 24th 04 11:48 AM

On Sun, 24 Oct 2004 03:10:04 GMT, "Mr Wizzard"
wrote:

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!!


Power pack?

Later,

Tom

Marshall Banana October 24th 04 12:42 PM

Also Sprach Short Wave Sportfishing :

Power pack?


No power pack in this old boy. It's basically an aircooled lawnmower
engine with an outboard leg. (I have one sitting in my garage)

To the OP... I'm thinking sparkplug wire maybe? Can you check with a
spark tester to see if the spark can jump the same gap on each cylinder?

Also, where ever did you find an electronic igniton for one of thses
things?

Dan

--
Every now and then when your life gets complicated and the weasels
start closing in, the only cure is to load up on heinous chemicals and
then drive like a ******* from Hollywood to Las Vegas ... with the
music at top volume and at least a pint of ether.

-- H.S. Thompson, "Fear and Loathing in Las Vegas"

Mr Wizzard October 24th 04 07:28 PM


"Short Wave Sportfishing" wrote in message
...
On Sun, 24 Oct 2004 03:10:04 GMT, "Mr Wizzard"
wrote:

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!!


Power pack?


What is a "power pack" ? ...This is an old Sea King 7.5 with
"type A" (I think) iginition, it's like a lawn mower, has one coil,
one condenser, and one set of breaker points for each of the
two cylingers, all of which is under the flywheel (which has just
one magnet).

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).







Later,

Tom




BenC October 24th 04 07:37 PM

"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?

Mr Wizzard October 24th 04 07:45 PM


"Marshall Banana" wrote in message
...
Also Sprach Short Wave Sportfishing :

Power pack?


No power pack in this old boy. It's basically an aircooled lawnmower
engine with an outboard leg. (I have one sitting in my garage)

To the OP... I'm thinking sparkplug wire maybe? Can you check with a
spark tester to see if the spark can jump the same gap on each cylinder?


I got a new coil (w/ spark plug wire), and switched coils, etc.




Also, where ever did you find an electronic igniton for one of thses
things?



Ah!, simple!. *Since* the flywheel has only "one" magent, you can
use these $13 universal ignition modules/breaker point eliminator
modules - I've been using them on ALL engine that comes thru here with
breaker points. Works great for 1, or 2 cylinder engines that uses a
magneto ignition where "one" magnet in the flywheel swings past a coil(s).
Its called a "Nova II", or a "universal ignition" module for small engines,
and can find them on line at any small engine supply outfit on the web.
They are about the size of a postage stamp, and eliminates the condenser,
and most importantly, the breaker points! - no more points in a 2-cylinder
means you don't have to worry about matching up point gaps, *or* worry
about situation where the lobe is worn that opens/closes the points (which
is how I got involved in these modules in the FIRST place). I re-did a 1974
Sears Gamefisher 7.5 (made by Eska w/ a Tecumseh engine) where the
lobe was too worn to open the points far enough. So pass this info on!!
For 1, or 2 cylinder OB's with flywheel/magneto ignitions, take the points
and condenser(s) out, and put one of these little things in, they are very
reliable! 2 terminals, and one screw, thats ALL there is to it!! Look :!

http://www.mfgsupply.com/m/c/31-8786.html

http://www.srnow.net/auto/detailview...323506&id3=YES

And last item on this list:
http://www.jackssmallengines.com/ignition_t.cfm


So yeah, I simply can't say enough about these little miricles!.
Now, back to my problem, any ideas ??













Dan

--
Every now and then when your life gets complicated and the weasels
start closing in, the only cure is to load up on heinous chemicals and
then drive like a ******* from Hollywood to Las Vegas ... with the
music at top volume and at least a pint of ether.

-- H.S. Thompson, "Fear and Loathing in Las Vegas"




Short Wave Sportfishing October 24th 04 07:55 PM

On Sun, 24 Oct 2004 18:45:04 GMT, "Mr Wizzard"
wrote:


"Marshall Banana" wrote in message
...
Also Sprach Short Wave Sportfishing :

Power pack?


No power pack in this old boy. It's basically an aircooled lawnmower
engine with an outboard leg. (I have one sitting in my garage)

To the OP... I'm thinking sparkplug wire maybe? Can you check with a
spark tester to see if the spark can jump the same gap on each cylinder?


I got a new coil (w/ spark plug wire), and switched coils, etc.




Also, where ever did you find an electronic igniton for one of thses
things?



Ah!, simple!. *Since* the flywheel has only "one" magent, you can
use these $13 universal ignition modules/breaker point eliminator
modules - I've been using them on ALL engine that comes thru here with
breaker points. Works great for 1, or 2 cylinder engines that uses a
magneto ignition where "one" magnet in the flywheel swings past a coil(s).
Its called a "Nova II", or a "universal ignition" module for small engines,
and can find them on line at any small engine supply outfit on the web.
They are about the size of a postage stamp, and eliminates the condenser,
and most importantly, the breaker points! - no more points in a 2-cylinder
means you don't have to worry about matching up point gaps, *or* worry
about situation where the lobe is worn that opens/closes the points (which
is how I got involved in these modules in the FIRST place). I re-did a 1974
Sears Gamefisher 7.5 (made by Eska w/ a Tecumseh engine) where the
lobe was too worn to open the points far enough. So pass this info on!!
For 1, or 2 cylinder OB's with flywheel/magneto ignitions, take the points
and condenser(s) out, and put one of these little things in, they are very
reliable! 2 terminals, and one screw, thats ALL there is to it!! Look :!

http://www.mfgsupply.com/m/c/31-8786.html

http://www.srnow.net/auto/detailview...323506&id3=YES

And last item on this list:
http://www.jackssmallengines.com/ignition_t.cfm


So yeah, I simply can't say enough about these little miricles!.
Now, back to my problem, any ideas ??


Change the module? :)

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 October 24th 04 08:04 PM

On Sun, 24 Oct 2004 18:28:50 GMT, "Mr Wizzard"
wrote:


"Short Wave Sportfishing" wrote in message
.. .
On Sun, 24 Oct 2004 03:10:04 GMT, "Mr Wizzard"
wrote:

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!!


Power pack?


What is a "power pack" ? ...This is an old Sea King 7.5 with
"type A" (I think) iginition, it's like a lawn mower, has one coil,
one condenser, and one set of breaker points for each of the
two cylingers, all of which is under the flywheel (which has just
one magnet).


Hey, it was a shot in the dark. :) I didn't see an answer, so I
thought I'd throw it out. My experience is with much later 2 cycle
engines and not much at that, although I have rebuilt one or two.

A power pack is similar to a coil in an auto.

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).


From my limited knowledge of this subject, I would think crank seal.

Later,

Tom

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

Wun Hung Lo - date unknown

Mr Wizzard October 24th 04 08:05 PM


"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 October 24th 04 08:14 PM


"Short Wave Sportfishing" wrote in message
...
On Sun, 24 Oct 2004 18:45:04 GMT, "Mr Wizzard"
wrote:


"Marshall Banana" wrote in message
...
Also Sprach Short Wave Sportfishing :

Power pack?

No power pack in this old boy. It's basically an aircooled lawnmower
engine with an outboard leg. (I have one sitting in my garage)

To the OP... I'm thinking sparkplug wire maybe? Can you check with a
spark tester to see if the spark can jump the same gap on each

cylinder?

I got a new coil (w/ spark plug wire), and switched coils, etc.




Also, where ever did you find an electronic igniton for one of thses
things?



Ah!, simple!. *Since* the flywheel has only "one" magent, you can
use these $13 universal ignition modules/breaker point eliminator
modules - I've been using them on ALL engine that comes thru here with
breaker points. Works great for 1, or 2 cylinder engines that uses a
magneto ignition where "one" magnet in the flywheel swings past a

coil(s).
Its called a "Nova II", or a "universal ignition" module for small

engines,
and can find them on line at any small engine supply outfit on the web.
They are about the size of a postage stamp, and eliminates the condenser,
and most importantly, the breaker points! - no more points in a

2-cylinder
means you don't have to worry about matching up point gaps, *or* worry
about situation where the lobe is worn that opens/closes the points

(which
is how I got involved in these modules in the FIRST place). I re-did a

1974
Sears Gamefisher 7.5 (made by Eska w/ a Tecumseh engine) where the
lobe was too worn to open the points far enough. So pass this info on!!
For 1, or 2 cylinder OB's with flywheel/magneto ignitions, take the

points
and condenser(s) out, and put one of these little things in, they are

very
reliable! 2 terminals, and one screw, thats ALL there is to it!! Look

:!

http://www.mfgsupply.com/m/c/31-8786.html

http://www.srnow.net/auto/detailview...323506&id3=YES

And last item on this list:
http://www.jackssmallengines.com/ignition_t.cfm


So yeah, I simply can't say enough about these little miricles!.
Now, back to my problem, any ideas ??


Change the module? :)


...This is the best you can come up with Tom? :) ...
I was somehow hoping for a different answer.
(hehe, never mind that inch and a half blue spark
I can draw off of the tip of the new plug wire that
is attached to that "new" coil driven by that brand
new module).




Later,

Tom

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

Wun Hung Lo - date unknown





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