Here is a discussion on the 155 Odd fire Firing order. http://omcboats.org/forum/viewtopic.php?f=7&t=398&p=676&hilit=odd+fire+order#p676 And here is a PDF of the OMC 150 Hp Stern drive Owners Manual. http://omcboats.org/forum/viewtopic.php?f=32&t=375 Hoggar. ----- Original Message -----
> This question is directed to anybody who has an odd-fire 225 in^3 V-6.
> I'm
> trying to trouble-shoot some ignition problems and it'd be nice to
> talk to
> somebody who a similar engine. I noticed that Dave Rusilas discussed
> having this engine in a post ~5 years ago (and again in 2010), so I'm
> hoping he's still got his and is reading the list.
> My points started sticking over the winter, so I opened up the
> distributor
> (first time since I bought the boat in '04) to clean them. After that
> the
> engine would start and idle just fine, but is popping (misfiring)
> under
> load. I think that may just be due to the points still being dirty and
> I've got some new ones coming (thought about doing Pertronix, but
> decided
> to replace the points instead) but that's not my main concern.
> The distributor is just as described by Dave below - a Delco Remy unit
> with
> mechanical advance, a screen on the distributor cap (which has evenly
> spaced contacts, both inside and out), and an elongated rotor.
> While I had it apart, I noticed that the order of the plug wires makes
> no
> sense. My OMC dealer service manual (for the exact make, model, and
> year
> of my boat) says that the contact on the distributor just to the
> "right" of
> the screen is #1, and that they increase in a clockwise order (looking
> from
> the top). But when I look at my distributor cap, the one marked #1 is
> exactly aligned with the screen and they increase counter-clockwise.
> My understanding is that the portside cylinders are 135 (front to
> rear) and
> the starboard cylinder are 246. The firing order marked on the valve
> cover
> is 165432, so I would assume that cylinder 1 should go to contact 1 on
> the
> distributor cap, cylinder 6 to 2, cylinder 5 to 3, cylinder 4 to 4,
> cyl 3
> to 5, and cyl 2 to 6.
> This isn't how it was wired though, either in the anti-clockwise order
> marked on the cap or the clockwise order specified in the manual.
> Unless my notes were wrong, they were wired as follows:
> cylinder numbered contact on distributor
> 1 2
> 2 1
> 3 3
> 4 4
> 5 5
> 6 6
> I can't come up with any rotation or reversal of this pattern that
> would
> yield the pattern I'm supposed to get. I'm wonder if I wrote down the
> ordering incorrectly? It seems unlikely, as I marked the wires one at
> a
> time in order as I removed them and it idles fine with the current
> configuration, but who knows? If my notes are correct, it's probably
> been
> that way for years.
> I am pretty sure that my engine is the odd-fire - the casting number
> on the
> block is 991503, which is supposed to be "V6, Odd-Fire, Kaiser Jeep
> Corp/AMC". I didn't look at the cam in the distributor, but the rotor
> has
> the elongated arm described by Jeff.
> To determine if your engine is an odd-fire, look at the casting number
> (visible on the top of the engine, at the back where it bolts onto the
> intermediate housing) and match it up with this list:
> http://nmr.mgh.harvard.edu/~reese/BuickV6CastingNumbersandInternalSpecs.pdf
> If anybody has an odd-fire V-6, is there any chance you could look at
> the
> distributor and tell me:
> a. Which port is #1? (relative to the screen and the front of the
> engine)
> b. Do the ports increase clockwise or counter-clockwise?
> c. What is the part number on your distributor cap?
> d. What order are the cylinders wired to the distributor?
> Thanks!
> Ethan
> On Wed, 30 Jul 2008, drusilas@... wrote:
> > 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 UNEVEN 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.
> --
> Ethan Brodsky
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Received on Monday, 10 June 2013
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