Re: [OMC-Boats] timing/carb adjustment

Jeff,

My boat is a 1969 Sportsman with an odd fire 155. It doesn't have the original block but I'm pretty sure that the distributor is original. It's a Delco Remy w/ centrifugal advance only. I'll try to get a distributor number off it later. The cap is held down by 2 screw latches and there is no gasket. It has a spark arresting screen breather on the side where the point's adjustment port?would be?on the auto version of the cap. The contacts are spaced evenly, 60 degrees apart from each other. The difference is in the rotor. Its contact is elongated by 15 degrees of arc to allow it to fire at both 45 and 75 degree intervals. The cam on the distributor shaft may have 45 - 75?spaced lobes. I'll look at it when it gets light outside and get back to you.

I think that the irregular spaced cap contacts that Lee is talking about are on the Delco HEI distributors. I tried to install one once but it wouldn't fit because the diameter of the cap is so large that it interfered with the thermostat housing. I opted for a Pertronix Igniter system instead and it works great. It uses a Hall Effect trigger set off by magnets on a ring which mounts below the rotor. Magnets are spaced around the ring at alternating 45 and 75 degree intervals. The part number is 1165 if you're interested.

Dave Rusilas

-----Original Message-----
From: JEFF DOOD <jdood@...>
To: Evinrude & Johnson Boats of the 1960's and 70's <omc-boats@...>
Sent: Tue, 29 Jul 2008 10:54 pm
Subject: Re: [OMC-Boats] timing/carb adjustment

awesome! i think i need to check out the underside of all my
collection of caps and see what's up. then make sure i try this
whole thing over with the odd fire distributer in there instead and
see what happens. esp if it would start, but not have power past 10
mph otherwise. sounds just like what my prob might be. plus i am
armed with more info to quiz my mechanic about.

on the car vs marine distributor topic though - i need some solid
info. i have heard car distributors are illegal and get you big
fines if discovered by the coast guard. also heard the reason is
due to the seal around the cap. marines are screwed down, cars
are not. spark can get out without screwed down seal. escaping
spark can blow things up. fine or no fine, not interested in the
blowing up part. so are the delco's just behind the times and
everything since has been brought up to more stringent safety
standards? and if the delco ends up working best with my engine,
should i be concerned about it not being a marine distributor?

On Jul 29, 2008, at 4:34 PM, Lee Shuster wrote:

> Jeff,
>
> Sorry if I confused you with a little too much info. I'll make it a
> little easier to understand:
>
> Since the distributor is gear driven off the camshaft, and the
> camshaft
> is driven by a 2:1 gear off the crankshaft, I could have explained the
> odd-fire timing interval in DISTRIBUTOR CAP DEGREES not relative
> CRANKSHAFT DEGREES. It's very helpful if you view
> http://home.off-road.com/~merls_garage/oddfire.html
>
> Let's look at your Mallory cap and assume for a minute that it is
> for a
> EVEN FIRE ENGINE: You are correct 360 / 6 (evenly spaced distributor
> posts is 60 degrees apart on the INSIDE of the distributor cap. I was
> correct in saving 120-120-120-120-120-120 of crankshaft rotation for
> each firing point because the crankshaft turns two revs for each rev
> of
> the distributor.
>
> If you examine in the INSIDE of a DELCO REMY ODD-FIRE Distributor you
> will notice UNEVE
N spacing of the contact traces. BUICK engineers
> altered the contact area to match a 45-75-45-75-45-75 degree pattern.
> The external wire sockets are NOT altered, the still are in the
> classic
> 60-degree spread. Pretty trick, eh?
>
> So as they say, your mileage my vary, but I suspect a +/- 15 degree
> isn't enough to keep the engine from starting with the wrong
> distributor
> cap. But I can well imagine, it doesn't idle very well and doesn't
> want
> to run more than 10 mph.
> So is it a case of mis-matched distributors?
>
> How do you solve this mystery? One certain way is to pull off a
> cylinder
> head and observe the piston timing. Another way might be to start
> looking for GM casting numbers or OMC serial number plate on the block
> and try and determine if you have an odd-fire 225 or an odd-fire
> 231, or
> an even fire 231 or even fire 252. I guess another method is trial and
> error substitution. And don't forget -- firing order matters, as well,
> as you have noted.
>
> It's too bad the mechanic didn't take notes or write what he did. It
> would be nice to get back to a known starting point, in figuring out
> where you are and where you are going. If your Buick came out of a
> dual-engine boat it is probably an odd-fire 225, but you can't be
> positive someone didn't change them out.
>
> It still sounds to me like you did get into an even-fire distributor
> with the Mallory. Don't worry about the vacuum advance that's the
> least
> of your problems. And I don't believe that OMC used marine-grade DELCO
> REMY distributors, but I could be wrong on that on the V6 Buicks.
>
> Lee
>
>
>
> -----Original Message-----
> From: omc-boats-bounces@...
> [mailto:omc-boats-bounces@...] On Behalf Of JEFF DOOD
> Sent: Tuesday, July 29, 2008 3:31 PM
> To: Evinrude & Johnson Boats of the 1960's and 70's
> Subject: Re: [OMC-Boats] timing/carb adjustment
>
> thanks lee, you might be on to something here. perfect timing too
> because i'm geared up to have to tow my boat
back over to the mechanic
> again tomorrow. i replied to specific parts of your email in caps:
>
>
> On Jul 29, 2008, at 10:43 AM, Lee Shuster wrote:
>
>> Hi Jeff,
>>
>> I'd like to ask a couple of "dumb" questions:
>>
>>>> So a short history on my boat: had "different" Buick 155 put in
>> my boat last winter.
>>
>> Do you know the history or source of your "different" Buick V6? Is
>> it a 225 Cu in or 231 Cu in?
>>
> NOT SURE - BOUGHT FROM A GUY WHO HAD TWO IN SOME SORT OF DUAL ENGINE
> BOAT (NEVER SAW WHICH BOAT)
>>
>> It's a long shot but --- You could have a even-fire crankshaft
>> (231) engine which requires a different distributor. Stay with me:
>>
>> The original OMC Buick V6's were all odd-fire and were 225 cu in.
>> They used Delco-Remy distributors designed specifically for the odd-
>> fire 225 cu in. Buick engineers first introduced the 90-degree
>> "Fireball" 198 CID V6 for the Buick Special & Skylark in 1961. In
>> 1964 Buick bumped the V6's displacement to 225 CID. The 90-degree
>> 225 CID V6 engine was essentially the 300 CID V8 with two cylinders
>> removed. Odd-fire V6 firing intervals were staggered at 90 and 150
>> degrees so the tooling could be shared with the V8. A 231 CID odd-
>> fire V6 was offered from '76 - '78.
>>
>> For smoother idling, Buick switched to a (weaker) split-pin
>> crankshaft, resulting in an even-firing V6 with the 231 & 252 CID
>> V6's midway through the 1977 model year and later. Even firing 6's
>> use 120 degree intervals. Hard for the average car mechanic to tell
>> the difference from external appearances.
>>
>> (Look at the distributor cap and you'll see the rather "odd" odd-
>> fire spacing, 90-150-90-150-90-150.) See my website for more details
>> on the odd-fire/even-fire Buick V6:
> http://hhscott.com/evinrude/buick_v6.htm
>>
>> If you want a more detailed explanation on the odd-fire oddities
>> see: http://home.off-road.com/~merls_garage/oddfire.html
>>
>
> WELL, CHECKED BOTH SITES - I'M GETTING LOST ON THE FIRE SPACING
> STUFF. REGARDLESS, PART OF
THIS COULD HAVE TO DO WITH THAT I HAD TO
> SORT OF GUESS AT WHICH WIRES WENT WHERE ON THE NEW DISTRIBUTOR'S
> CAP. I'M PRETTY CONFIDENT ABOUT WHICH CYLINDERS ARE #1, #2 ETC.
> THE PREVIOUS CAP WAS MARKED WITH NUMBERS AND BEFORE TAKING OFF IT OFF
> I MARKED THE PLUG WIRES. [THE #1 IS FRONT RIGHT SIDE WHEN VIEWING
> FROM THE FRONT. ALL THE ODD'S ARE ON THE PORT, EVENS ON THE SB. ]
> BUT THE NEW CAP DOESN'T EVEN HAVE #1 MARKED ANYWHERE LIKE THE
> OTHERS. BUT ACCORDING TO THE MANUAL THE ROTOR POINTS TO THE FRONT
> WHEN #1 PISTON IS AT TOP DEAD CENTER. AND THE ORDER OF THE WIRES
> ON THE PREVIOUS CAP WAS COUNTER CLOCKWISE STARTING WITH #1. AND THE
> NEW CAP (AND PREVIOUS) HAVE A PIN TO ALIGN THEM WITH THE
> DISTRIBUTOR. SO I GOT THE #1 PISTON AT TDC, ROTOR POINTING TOWARDS
> FRONT, AND SINCE THE CAP ONLY GOES ON ONE WAY, MADE THE ASSUMPTION
> THAT #1 MUST BE RIGHT WHERE THE ROTOR WAS POINTING (WHICH MATCHED WHAT
> THE MANUAL SAID). THEN I PLUG IN THE WIRES IN SEQUENCE GOING CCW
> AROUND THE CAP. DID I DO THAT RIGHT?
>
> TO ADD TO THE MIX HERE, YOU MENTIONED DELCO REMY DISTRIBUTORS. THE
> "ORIGINAL" DISTRUBUTER THAT WAS ON THE ENGINE WHEN I BOUGHT IT (BEFORE
> THE CAR DISTRIBUTER THE MECHANIC PUT ON) SAID DELCO - REMY ON THE
> TOP. IT'S A BIG CAP, ABOUT TWICE THE SIZE OF THE MALLORY. AND IT
> DOESN'T LOOK LIKE A TYPICAL DIST CAP. SO IF THE ODD FIRES CAME WITH
> THOSE DISTRIBUTERS, PERHAPS THAT MIGHT INDICATE I HAVE AN ODD FIRE.
> HOWEVER, THERE'S NO GUARANTEE THOSE WERE NECESSARILY "ORIGINAL"
> EITHER. BUT MY GUESS WOULD BE THEY WERE.
>
> I STILL AM NOT SURE WHY THE MECHANIC TOOK THAT DELCO REMY OFF AND PUT
> ON THE OTHER "CAR" DIST.
>
> AND JUST TO ADD EVEN MORE CONFUSION IN HERE, THE "CAR" DISTRIBUTOR
> PUT ON BY THE MECHANIC HAD THAT SAME VACUUM TUBE THING STICKING OFF
> THE FRONT LEFT SIDE, JUST LIKE THE "CORRECT" DISTRIBUTER SHOWN ON THE
> ENGINE IN YOUR PHOTO AT YOUR SITE. BUT THAT'S THE SPECIFIC PART
> THE GUY AT THE DOCK POINTED TO AND SAID "THERE'S YOUR PROBLEM, YOU

> HAVE A CAR DISTRIBUTOR ON THERE, SEE THAT VACUUM THING ON THE
> FRONT?" SHEESH. AND WHEN I MENTIONED THE PREVIOUS
> DISTRIBUTER THAT HE FOR SOME REASON REMOVED SAYING "DELCO REMY" ON IT,
> HE SAID "OH YEAH, THAT'S A CAR DISTRIBUTOR" - (HEARING ME SAY
> "DELCO"). PART OF THE PROB IS HE'S THE SHOP OWNER WITH THE SUPPOSED
> OMC EXPERIENCE, YET HIS UNDERLING HAS BEEN DOING ALL THE WORK ON THE
> ENGINE. SO HE DIDN'T KNOW WHY THE GUY TOOK IT OFF EITHER, AND
> MENTIONED MAYBE CLEARANCE WITH THE COWLING ISSUES (I LATER TESTED AND
> IT CLEARED.) AND NEITHER THE DELCO REMY'S OR THE MALLORY THAT I
> HAVE ON THERE NOW HAVE THAT LITTLE VACUUM THING ON THE FRONT LIKE
> YOUR PHOTO. THOROUGHLY CONFUSED YET?
>
> TO CUT TO THE CHASE, I STILL HAVE THE DELCO REMY. IN FACT TWO OF
> THEM. HOW COMPLETE THEY ARE I DON'T KNOW, BUT ASSUMABLY I COULD
> ROUND UP POINTS, ROTOR, CONDENSER.
>
> BUT THIS ALL BEGS THE QUESTION(S) - IF I HAVE AN EVEN FIRE DISTRIBUTOR
> ON AN ODD FIRE ENGINE, AND/OR HAVE MY PLUG WIRES IN THE WRONG ORDER
> ON THE CAP, WOULDN'T ALL THAT PREVENT THE ENGINE FROM STARTING AT
> ALL?
>
> IS MISSING THAT VACUUM THING PART OF THIS? THERE DOES NOT APPEAR TO
> BE A PLACE TO CONNECT UP THE OTHER END OF A TUBE ON MY CARB ANYWAY.
>
>
>>
>>
>> Was your "mechanic" a car guy or an experienced OMC marine guy?
>>
> SO HE SAYS.
>>
>>
>> Your used Mallory Marine distributor? Is it possible you got an even-
>> fire V6 distributor and stuck it into your odd-fire? Check the
>> inside of the distributor cap: Evenly spaced 6's are
>> 120-120-120-120-120-120 degrees apart.
>>
> CONFUSED ABOUT THIS. HOW CAN I TELL THE DEGREES? THERE'S SIX PORTS
> ALL EVENLY ARRAYED AROUND THE 360 DEGREES OF THE CAP (60 d APART?).
> WHERE'S THE 120 ?
>
>
>> I have never heard of a Mallory distributor being used on an odd-
>> fire Buick, but I suppose anything is possible. Also, re-check the
>> firing order: The odd-fire firing order is 1-6-5-4-3-2.
>>
>> The even-numbered cylinders are starboard, while the
odd-numbered
>> cylinders are port-side.
>>
>
> MY ODDS ARE ON PORT SIDE.
>> The heads feature an unusual valve arrangement: E-I-E-I-I-E (port
>> bank, stated from front to rear, or starboard bank, stated from rear
>> to front.) (Where Even-fire Firing Order is: 1-6-3-5-2-4)
>>
>> There's some very strange possibilities going on here -- This thread
>> is beginning to remind we of Click & Clack!
>>
>> Hang in there -- I'm just trying to help out by figuring out exactly
>> what you have. Do you have a SELOC or OMC shop manual? that would
>> be helpful.
>>
>
> I DO HAVE BOTH ACTUALLY. BUT THE SELOC I THINK IS FROM THE MID 70'S
> ON.
>>
>>
>> Oh yeah, what carb do you have? OMC used both 1-barrel (1964-65)
>> and 2-barrels (1966 - 1970). I think the 1-barrel's were Carter's
>> and the 2-barrels were Rochester's.
>>
>
> AH YES, THE CARB. IT'S A ROCHESTER 2 BARREL.
>
>
> AND ON A SIDE NOTE- AFTER GLANCING OVER THE AFTERMARKET "BEEF UP
> YOUR ENGINE" STUFF YOU MENTION AT YOUR SITE, I AM ABOUT READY TO SAY
> TO HELL WITH MY POSSIBLY MIS-MATCHED WHO KNOWS WHAT CARB AND
> DISTRIBUTOR AND GO FOR NICE NEW BEEFIER STUFF. I PLAN ON KEEPING
> THIS BOAT FOR A LONG TIME. JUST BOUGHT NEW SEATS FOR IT. I WANT
> AN ENGINE THAT STARTS AND RUNS AS RELIABLY AS IT POSSIBLY CAN. I'M
> SITTING HERE TRYING TO LEARN HOW TO SET THE TIMING, KNOWING THAT IF I
> DON'T IT MEANS WEEKS AT THE MECHANIC AND $$ EVERY YEAR. BUT IF
> THERE'S SOME SORT OF UPGRADE THAT WOULD GET ME A NO TUNING NEEDED
> ELECTRONIC IGNITION, I AM ALL FOR IT.
>
>
>>
>>
>> Lee Shuster
>> Salt City
>>
>>
>> -----Original Message-----
>> From: omc-boats-bounces@...
> [mailto:omc-boats-bounces@...
>> ] On Behalf Of JEFF DOOD
>> Sent: Tuesday, July 29, 2008 10:00 AM
>> To: Evinrude & Johnson Boats of the 1960's and 70's
>> Subject: Re: [OMC-Boats] timing/carb adjustment
>>
>> .....so many applicable topics on this list to what i'm going through
>> with my boat right now. first off, i have a mechanic, but i dread
>> hav
ing to leave my boat with him because i usually don't see it for
>> another month. So i have been crash coursing myself to try learn
>> about my engine and work on it myself as much as possible. i am
>> good with cars, great with electrical stuff. boat engine stuff -
>> so
>> so. and when it gets into timing and carb adjustment i am really
>> feeling my way through it. i haven't even done that on a car yet.
>>
>>
>> So a short history on my boat: had "different" Buick 155 put in my
>> boat last winter. mechanic got it running, starting, but never water
>> tested. a few weeks back took it out for test, started fine, ran
>> ok at low speed, but lost all power at about 10mph. He thought
>> carb rebuild needed. i rebuilt carb that weekend. test ran and
>> still had same problem. Although adjusting it was kind of a guessing
>> game. My mechanic said to screw the two adjustment screws in all
>> the
>> way until the engine almost stalls, then back them out about a turn
>> and a half. he also said to do this while boat was underway, not
>> idling in neutral. Well i did this, and had the screws in about
>> every conceivable position and always the same thing - no power at
>> about 10 mph.
>>
>> So back to the dock i slowly went. Random guy at the dock
>> suggested it might be a bad distributer. (mechanic didn't bother
>> telling me i had a car distributer on there). So i got a used but
>> good condition, SUPPOSEDLY original Mallory distributer. replaced
>> points, condenser, installed this past weekend. Went to dock to for
>> timing last night. (First time i have ever timed anything). Got
>> it started, idled alittle rough but nothing major. Twisted the
>> distributer and got the white mark to mostly line up with the "5" as
>> spec'd in the manual. Seemed to smooth out idle at first. Then i
>> played with carb screws again. Double checked timing, etc etc.
>> End result is same thing, except maybe a little worse. now
>> idles a
>> little rough
and stalls out at about 10 mph.
>>
>> Any suggestions?
>>
>> When setting the timing, is the white mark that is to be line up
>> with the "5" supposed to bounce all over making it really difficult
>> to line up exactly?
>>
>> how important is the tach in this process? i have no working
>> tach. But in theory, shouldn't i be able to get things get pretty
>> close by just listening to the engine?
>>
>> am i adjusting the carb correctly? is there a sequence to
>> adjusting all this stuff - carb then timing? timing then carb?
>>
>> if i end up having to replace the carb altogether, is there an
>> source
>> for those out there? new? used?
>>
>>
>> would sure love to use my boat this summer!
>>
>> thanks, jeff
>>
>>
>>
>>
>>
>> On Jul 28, 2008, at 1:58 PM, Don Mandelas wrote:
>>
>>> Ethan, I undertsand what your saying. I'll recheck the RPMs with
>> the
>>> timing light again and double check the settings. (I'll re-do the
>> test
>>> so that I'm confident with the results). Maybe I'll even get the
>>> tinytach you were talking about.
>>>
>>> Don.
>>>
>>>
>>>> Date: Mon, 28 Jul 2008 13:42:35 -0500
>>>> From: brodskye@...
>>>> To: omc-boats@...
>>>> Subject: Re: [OMC-Boats] Engine RPM and Boat Speed
>>>>
>>>> On Sun, 27 Jul 2008, Don Mandelas wrote:
>>>>> This weekend I was able to obtained a timing light and digitally
>>> measure
>>>>> the revalutions per minute of my V-6 155 hp boat engine.
>>>>> I discovered that when the timing light indicated 1,100 RPM's my
>>> boat
>>>>> tachometer was reading 1,000 RPM's. And, when the timing light
>>> indicated
>>>>> 4,000 RPM's my boat tachometer was reading 3,000 RPM's. This
>>> means my
>>>>> tachometer is reading a full 1,000 rpms below what it should be
>>> on the
>>>>> higher end of the scale and is probably the primary reason why I
>>> am going
>>>>> slower than normal. I'll replace the tachometer and try the boat
>>> again.
>>>>
>>>> This sounds a little strange - you say that the tach is reading
>>> low, so the
>>>> engine
 is actually spinning faster (and making more power) than
>>> believed.
>>>>
>>>> I found the opposite on mine - when I measure the RPM (using a
>>> TinyTach
>>>> inductive pick-up on a spark wire), I see that the tach is reading
>>>> substantially high (1000-1500 rpm). My understanding is that older
>>> tachs
>>>> tend to read high due to weakening of the return spring with age.
>>>>
>>>> Are you sure you had the timing light set properly (some can be
>>> switched
>>>> between various combinations of two-stroke/four-stroke, single/
>> multi
>>>> cylinder, and wasted-spark modes) and it wasn't reading high by a
>>> factor of
>>>> two? I'm not sure how it works with older distributors, whether
>>> each spark
>>>> plug fires once for every revolution or just every second time. I
>>> think
>>>> it's the latter.
>>>>
>>>> Tinytachs are a fairly cheap way to have a more accurate RPM
>>> reading, as
>>>> well as an hour-meter. Unfortunately I don't remember whether the
>>> 4C or
>>>> the 2C should be used.
>>>> http://www.tinytach.com/tinytach/gasoline.php
>>>>
>>>> If anyone has figured out a way to adjust the factory OMC facts,
>>> I'd like
>>>> to fix mine. I haven't figured out how to do that yet.
>>>>
>>>> Ethan
>>>>
>>>> --
>>>> Ethan Brodsky
>>>> _______________________________________________
>>>> OMC-Boats mailing list
>>>> OMC-Boats@...
>>>> http://lists.ultimate.com/mailman/listinfo/omc-boats
>>>
>>>
>>> Keep your kids safer online with Windows Live Family Safety. Help
>>> protect your kids. _______________________________________________
>>> OMC-Boats mailing list
>>> OMC-Boats@...
>>> http://lists.ultimate.com/mailman/listinfo/omc-boats
>>
>> _______________________________________________
>> OMC-Boats mailing list
>> OMC-Boats@...
>> http://lists.ultimate.com/mailman/listinfo/omc-boats
>>
>> _______________________________________________
>> OMC-Boats mailing list
>> OMC-Boats@...
>> http://lis
ts.ultimate.com/mailman/listinfo/omc-boats
>
> _______________________________________________
> OMC-Boats mailing list
> OMC-Boats@...
> http://lists.ultimate.com/mailman/listinfo/omc-boats
> _______________________________________________
> OMC-Boats mailing list
> OMC-Boats@...
> http://lists.ultimate.com/mailman/listinfo/omc-boats

_______________________________________________
OMC-Boats mailing list
OMC-Boats@...
http://lists.ultimate.com/mailman/listinfo/omc-boats
Received on Wednesday, 30 July 2008