There is a good book by David Vizard called "How to Rebuild Your Small Block 
Chevy" - not sure if it is still in print but may be available somewhere. It 
covers all bases. The plug with no gap - could something loose in the 
cylinder have impacted the tip of the plug and bent the end? Just a thought. 
I would keep digging till I found the culprit. These motors are so 
unsophisticated by todays standards that I wouldn't worry too much - you can 
always figure it out with us and or internet expertise. TK
----- Original Message ----- 
From: <omc-boats-request@...>
To: <omc-boats@...>
Sent: Tuesday, September 08, 2009 12:00 PM
Subject: OMC-Boats Digest, Vol 29, Issue 11
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> Today's Topics:
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>   1. Re: delving into scaryland.... (BLDFW)
>   2. Re: delving into scaryland.... (Lee Shuster)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 8 Sep 2009 06:56:34 -0700 (PDT)
> From: BLDFW <bldfw@...>
> Subject: Re: [OMC-Boats] delving into scaryland....
> To: "Evinrude & Johnson Boats of the 1960's and 70's"
> <omc-boats@...>
> Message-ID: <119985.68409.qm@...>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I've pulled a?couple of engines apart to do a rebuild.? The tube or bar is 
> just holding the valve rocker?arms in place.? It?rests on top of the rods 
> and the springs.? The springs hold the actual valves and are held in place 
> by a snap ring that holds the little round 'cover' you see.? You are safe 
> to remove the bar and the rocker arms.? They will either lift out with the 
> bar or will just rest on the rods and valves and you can pluck them off 
> one at a time.
> ?
> The heads, once unbolted, will have to be gently prided up to free them 
> from the block and yes, they will be trashed so you will need a new gasket 
> set.? Since you have already gone this?far, I would seriously 
> recommend?considering going the next logical?step and?sending the heads 
> out for a valve job.? Would be a shame to waste breaking the engine down 
> this far and not doing that but then again,?if it's not necessary, no 
> sense in doing it either.
> ?
> Good luck and keep us posted!
> ?
> -Bill
> Dallas, TX
> 1970 Evinrude Explorer - 155 Buick V6 - OMC Sterndrive
> http://www.photobucket.com/evinrude_explorer
> ?
> ?
>
>
> --- On Tue, 9/8/09, jd <jdood@...> wrote:
>
>
> From: jd <jdood@...>
> Subject: [OMC-Boats] delving into scaryland....
> To: "Evinrude & Johnson Boats of the 1960's and 70's" 
> <omc-boats@...>
> Date: Tuesday, September 8, 2009, 12:30 AM
>
>
> right on the heels of getting my switch issue overwith,? and having a 
> fabulously smooth 30 min test at WOT right after the other day,???I was 
> ready for a real outing.? ? but of course, not without a new issue to 
> solve springing up.???and not a pretty one.???I was at the dock 
> (fortunately) and had just got back from my test run.???Was playing with 
> idle trying to get it to go down to where it's supposed to (sticky cable 
> issue i think).???in the spirit of trying to learn what does what,? i 
> pulled off the spark arrester and started playing with the flapper inside 
> the carb.???a tiny little brass screw that partially held the flapper 
> together was barely screwed in and sure enough dropped down into the black 
> abyss of the carb, never to be seen again.? ? I put stuff back together,? 
> started,? no probs -smooth.???started moving the red throttle lever back 
> and forth.? ???all of the sudden a clanking noise.???however,?
> coincidentally NOT the screw - a much bigger clanking noise,? and only at 
> low idle - often causing stalls.???And in fact,? i had heard this same 
> noise 2-3 months ago during a start up.???immediately shut it down.???it 
> never came back,? and i forgot about it.???so here it was again, this time 
> a lot worse and causing engine to stall.? ? a car mechanic guy happened to 
> be at the dock,? listened around the engine with me,? sounded like it was 
> coming from the port side,? deep within somewhere.? ? It's definitely the 
> sound of a "metal piece" sort of bouncing and clanking around inside the 
> engine.???It's not a rattle type sound,? more of a random clanking - like 
> coins in a dryer.???And it sounds big - not like a tiny brass screw, but a 
> nut or something bigger.???ugh.
>
>
> So long story short,? he suggested i start with the valve covers and see 
> it anything is loose.? ? the remove the intake manifold.? ? as you can 
> see,? have done both.???jiggled a tiny little piece of solder (from a 
> previous owner's attempt at repairing carb flapper) out of the IM,? but no 
> brass screw.? ? So now I'm on to the only next place I can go,? the 
> cylinders.???Pulled the plugs out,? nothing unusual with them.???One had 
> NO gap whatsoever,? but probably unrelated.? time for new plugs 
> regardless.
>
> So my questions are these:? ? I'm about the pull off the cylinder 
> heads.???have never gone this far into any engine.???and am flying 
> somewhat blind.???yes,? i have all OMC 3 original manuals.? yes, i've read 
> them.???they aren't much help.? ? So excuse my ignorance beyond this 
> point.???But there's no way I am handing my boat off to another mechanic 
> for another year.???Gotta go it alone.....
>
> 1)As shown in the photo.???there appear to be about 8 bolts holding the 
> heads on.? 4 inside,? 4 down by plugs.???but unscrewing those doesn't look 
> like it will do much because all the valve stuff.? ? So if i undo the 3 
> bolts holding that bar of levers,???will it just come off easily and allow 
> for the rest of the head to come off somehow,? or will springs go flying 
> everywhere?? I don't wanna mess with valves if i can help it.? just wanna 
> get to the cylinders.???So much easier on a lawn mower.? ???Manual says 
> remove heads WITH manifolds still attached.???But can't get to a couple 
> bolts cause manifold gasket is in the way.? ? So i guess I'll be taking 
> those off as part of this.
>
> 2) Will the head gaskets be trashed after this,? or salvagable?? Anyone 
> know right off hang if they are they out there for sale,? or one of those 
> impossible to find way overpriced no longer made vintage parts????Yes I 
> will poke around online,? but just trying to get an idea....
>
> 3) After i get the heads off,? I'm assuming I will be able to see the tops 
> of the pistons.???I'm not expecting much,? but perhaps I'll find something 
> obvious clanking around in one of the cylinders.???perhaps a coin,? or a 
> wedding ring,? or maybe the top half of a spark plug.? ? probably not.? 
> ???So where is the next place deeper within that something could be 
> clanking around?? what's under the cylinders?? Could the oil pump be 
> making that noise?? It wouldn't cause the stalling though.
>
> glad it's the end of the season.
>
> thanks for any help,? Jeff D
>
>
> -----Inline Attachment Follows-----
>
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> ------------------------------
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> Message: 2
> Date: Tue, 8 Sep 2009 09:00:10 -0600
> From: Lee Shuster <lks@...>
> Subject: Re: [OMC-Boats] delving into scaryland....
> To: "Evinrude & Johnson Boats of the 1960's and 70's"
> <omc-boats@...>
> Message-ID: <71585B53-EB7D-41D5-B56C-36AB5D5199FC@...>
> Content-Type: text/plain; charset="us-ascii"; Format="flowed";
> DelSp="yes"
>
> JD,
>
> One tool that you'll find invaluable is the illustrated OMC Parts
> Catalog. Available FREE online at BRP-OMC or CROWLEYMARINE.COM. OR you
> can but a REAL HARD COPY at BRP or look forever on eBay. I feel like a
> broken record, but I get the idea few of us have these, by the nature
> of a lot of the questions that crop up here.
>
> Careful study of this "EXPLODED" diagram will revel (4) bolts holding
> each cyl head to the block. It is a simple as your lawn mower, times 6
> cylinders. With the OMC PARTS CATALOG it's like you have X_RAY vision!
>
> New Parts for the 3.7 Litre or 225 cu in ODD_FIRE BUICK V6 are
> relatively plentiful and easy to obtain including rebuilt short or
> long blocks. Even the OMC log-style. exhaust manifolds are still
> available, but they are expensive, see below)
> Nothing particularly expensive or specialized, as GM and Jeep built
> this engine for years. Just don't confuse it with it's 231 cu in
> (3.8L) even-fire sister. Anything you might need for this engine is
> available, if you carefully explain what you have and ask the right
> sources. This was probably the second most popular GM engine that OMC
> used after the 100-110-120-140 Chevy-II 4-banger.
>
> If this were my project, I'd start by having getting help to remove
> the stern leg. Then I'd carefully determine if there's room on your
> boat to pull the engine and intermediate out as a unit to gain better
> working access in a clean shop environment.
> IF YOU DO LEAVE THE EXHAUST MANIFOLDS ATTACHED -- BE CAREFUL. It is
> easy to stress (causing cracks) in the head mating flanges by lifting
> on the manifolds, so DON'T DO iT!).  This will cost you big money. If
> it were mine, I'd carefully remove the exhaust manifolds, before
> removing the heads, to reduce the weight and possibility of ruining
> the manifolds.
>
> And Bill's right, treat that motor to a nice valve job. They'll most
> likely install modern hardened valve seats (for lead free gas).
>
> The timing is right to get started on good off-season project.  Also,
> the fact that you mentioned a spark plug with NADA-gap is SIGNIFICANT.
> That plug most likely has encountered MECHANICAL interference and will
> PROBABLY be a clue as to where the SOURCE of your strange NOISE is.
>
> BTW, what year/model is you boat?  From you pictures, your Buick V6
> appears to have been retrofitted from a 72-73 era OMC. Do you have a
> serial number or model number off the engine tag? It's not all that
> important, just curious.
>
> Lee
>
> On Sep 8, 2009, at 7:56 AM, BLDFW wrote:
>
>> I've pulled a couple of engines apart to do a rebuild.  The tube or
>> bar is just holding the valve rocker arms in place.  It rests on top
>> of the rods and the springs.  The springs hold the actual valves and
>> are held in place by a snap ring that holds the little round 'cover'
>> you see.  You are safe to remove the bar and the rocker arms.  They
>> will either lift out with the bar or will just rest on the rods and
>> valves and you can pluck them off one at a time.
>>
>> The heads, once unbolted, will have to be gently prided up to free
>> them from the block and yes, they will be trashed so you will need a
>> new gasket set.  Since you have already gone this far, I would
>> seriously recommend considering going the next logical step and
>> sending the heads out for a valve job.  Would be a shame to waste
>> breaking the engine down this far and not doing that but then again,
>> if it's not necessary, no sense in doing it either.
>>
>> Good luck and keep us posted!
>>
>> -Bill
>> Dallas, TX
>> 1970 Evinrude Explorer - 155 Buick V6 - OMC Sterndrive
>> http://www.photobucket.com/evinrude_explorer
>>
>>
>>
>>
>> --- On Tue, 9/8/09, jd <jdood@...> wrote:
>>
>> From: jd <jdood@...>
>> Subject: [OMC-Boats] delving into scaryland....
>> To: "Evinrude & Johnson Boats of the 1960's and 70's" 
>> <omc-boats@...
>> >
>> Date: Tuesday, September 8, 2009, 12:30 AM
>>
>> right on the heels of getting my switch issue overwith,  and having
>> a fabulously smooth 30 min test at WOT right after the other day,
>> I was ready for a real outing.    but of course, not without a new
>> issue to solve springing up.   and not a pretty one.   I was at the
>> dock (fortunately) and had just got back from my test run.   Was
>> playing with idle trying to get it to go down to where it's supposed
>> to (sticky cable issue i think).   in the spirit of trying to learn
>> what does what,  i pulled off the spark arrester and started playing
>> with the flapper inside the carb.   a tiny little brass screw that
>> partially held the flapper together was barely screwed in and sure
>> enough dropped down into the black abyss of the carb, never to be
>> seen again.    I put stuff back together,  started,  no probs -
>> smooth.   started moving the red throttle lever back and forth.
>> all of the sudden a clanking noise.   however,  coincidentally NOT
>> the screw - a much bigger clanking noise,  and only at low idle -
>> often causing stalls.   And in fact,  i had heard this same noise
>> 2-3 months ago during a start up.   immediately shut it down.   it
>> never came back,  and i forgot about it.   so here it was again,
>> this time a lot worse and causing engine to stall.    a car mechanic
>> guy happened to be at the dock,  listened around the engine with
>> me,  sounded like it was coming from the port side,  deep within
>> somewhere.    It's definitely the sound of a "metal piece" sort of
>> bouncing and clanking around inside the engine.   It's not a rattle
>> type sound,  more of a random clanking - like coins in a dryer.
>> And it sounds big - not like a tiny brass screw, but a nut or
>> something bigger.   ugh.
>>
>>
>> So long story short,  he suggested i start with the valve covers and
>> see it anything is loose.    the remove the intake manifold.    as
>> you can see,  have done both.   jiggled a tiny little piece of
>> solder (from a previous owner's attempt at repairing carb flapper)
>> out of the IM,  but no brass screw.    So now I'm on to the only
>> next place I can go,  the cylinders.   Pulled the plugs out,
>> nothing unusual with them.   One had NO gap whatsoever,  but
>> probably unrelated.  time for new plugs regardless.
>>
>> So my questions are these:    I'm about the pull off the cylinder
>> heads.   have never gone this far into any engine.   and am flying
>> somewhat blind.   yes,  i have all OMC 3 original manuals.  yes,
>> i've read them.   they aren't much help.    So excuse my ignorance
>> beyond this point.   But there's no way I am handing my boat off to
>> another mechanic for another year.   Gotta go it alone.....
>>
>> 1)As shown in the photo.   there appear to be about 8 bolts holding
>> the heads on.  4 inside,  4 down by plugs.   but unscrewing those
>> doesn't look like it will do much because all the valve stuff.    So
>> if i undo the 3 bolts holding that bar of levers,   will it just
>> come off easily and allow for the rest of the head to come off
>> somehow,  or will springs go flying everywhere?  I don't wanna mess
>> with valves if i can help it.  just wanna get to the cylinders.   So
>> much easier on a lawn mower.     Manual says remove heads WITH
>> manifolds still attached.   But can't get to a couple bolts cause
>> manifold gasket is in the way.    So i guess I'll be taking those
>> off as part of this.
>>
>> 2) Will the head gaskets be trashed after this,  or salvagable?
>> Anyone know right off hang if they are they out there for sale,  or
>> one of those impossible to find way overpriced no longer made
>> vintage parts?   Yes I will poke around online,  but just trying to
>> get an idea....
>>
>> 3) After i get the heads off,  I'm assuming I will be able to see
>> the tops of the pistons.   I'm not expecting much,  but perhaps I'll
>> find something obvious clanking around in one of the cylinders.
>> perhaps a coin,  or a wedding ring,  or maybe the top half of a
>> spark plug.    probably not.     So where is the next place deeper
>> within that something could be clanking around?  what's under the
>> cylinders?  Could the oil pump be making that noise?  It wouldn't
>> cause the stalling though.
>>
>> glad it's the end of the season.
>>
>> thanks for any help,  Jeff D
>>
>>
>> -----Inline Attachment Follows-----
>>
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> End of OMC-Boats Digest, Vol 29, Issue 11
> ***************************************** 
Received on Tuesday,  8 September 2009
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