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Vintage Australian Outboard Runabouts => Information Wanted => Topic started by: antman on December 15, 2018, 12:34:01 PM

Title: mercury 650ss 1967 4 cyl
Post by: antman on December 15, 2018, 12:34:01 PM
Hi im Ant
thanks for your exellent forum
ive been googling nd tinkering for 6 months on my problem
I aquired a 14.5 fibreglass runabiut with a 650 ss engine
the engine started ,but hadnt been used for 18 months and little use before that 
on its first run on the bay it  only reved to estimated 2500 rpm (tacho not working ) and could not get the hull planning
off to mechanic ,, was told dizzy not advancing .. get new dizzy
back in the shead  , after amber thinking liquid ....grease nipples
test on bay ..... yep fixed plaining ..going hard and fast !  ;D
10 min later it dies  >:( restarts .then dies  row home
weeks of tinkering i book in to another mechanic
i was told ..the timming is way out    need a new dizzy
took it home and pulled bits off to investigate
= the rotor is at lead 1
=the pully arrow on the top ofthe dizzy assembley is alligned with the rotor
=the arrow mates up perfectly with the 2 dots on the fly wheel
=teh number 1 piston is at the BOTTOM of the stroke ( number 2 piston is at tdc)
what he ? whats happened here ?
so i move all the leads around ..hence engine timming is 180 deg out
and the thing starts 
took to water ..idled out then stopped
returned to garage and checked it out again
now everything is  reversed again back 180 deg ! i put leads back  .but now wont start ... timming is good leads right got spark gotfuel ???
1  how can this happen
i after 1 month of thinking and wraking peoples heads and googling have deduted thet the flywheel must be moving
but then i think the timming marks would move
but if the pulley thet drives the dizzy is fixed to the flywheel then  the timming marks would be correct .
but if the pulley is on the crankshaft ... it would have to move and be out
i so confused ..its been 9 months of crash coarse 2 stroke outboard learning

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on December 18, 2018, 06:32:05 AM
Wow, your head must be spinning. (unlike your motor)

If I was there, I'd be removing the flywheel to check the key hasn't been sheared. Perhaps someone has removed the key just for a joke? I've honestly discovered that before! That will throw the timing out the window.
Then I'd check the condition of the underside of the flywheel and make sure nothing is loose or broken.

By the way, has the motor been coughing or sneezing at all? Is fuel spitting out of a carbie perhaps?

Keep us posted, this won't be too hard (said the actress to the bishop)

AA are you there? I'm coughing and sneezing at the moment with a summer cold. Do you think I may have a loose/broken or damaged Reed or perhaps a timing problem?


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on December 18, 2018, 06:43:57 PM
thanks Mercman ill check it out ..and post the results

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on December 24, 2018, 11:48:18 AM
confirmed broken key on flywheel  pulley connected to flywheel which explaines everything to do with timing marks not being out  now hunting for woodroff key
 by the way can anybody identify this hull ..

Title: Re: mercury 650ss 1967 4 cyl
Post by: andrewallan on December 26, 2018, 01:58:09 PM
Welcome Antman, and seasons greetings to you all. Sad when 2 paid mechanics haven’t resolved your problem!

Mercman, I have no idea about loose or broken reeds! I was firmly told by Mark S last year NOT to remove the cowl on my engine! Am off down to the beach tomorrow for 10 days, and might get the “trusty” Hartley in the water, dependent on the number of nimwits using the boat ramp, and the length of the queues to said boat ramp! If not, then will get some water time after January. still some anxiety about boating, as she ran really well for the first 3/4 of. The last trip, and really badly for the last bit!


Title: Re: mercury 650ss 1967 4 cyl
Post by: senojn on December 26, 2018, 06:21:45 PM
Hi A
Nice to hear from you . You do love your boating so I trust February will be kind to you although my logic suggests the 1st quarter will start as the last quarter finished  ;)
I still admire my girl sitting in the back yard as we also find ramps difficult in our 70's.

Hope you have recovered Merman as you are now back in the fast lane .
Chicago deserves a lot of time with it's testosterone atmosphere and the magnificent buildings including the 'Smithsonians '
Nautically  (to stay with the 'board ' I remember posting photos of the Chicago river and the lock which allows accesses to Lake Michigan .
Happy New Year to all .

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on December 29, 2018, 10:35:27 AM
Congrats' on finding your obvious problem.  ;D . The replacement Crankshaft Key you are looking for, can be easily found at you local outboard wrecker. Ther are that typical with many model's its not funny.
As for the hull, that particular pic makes me say: Swiftcraft Falcon, perhaps.

Is that your motor you have been posting about? You said yours was a 650SS.
The cowls in the pic tells me they are 1973/4 Cowls. There was no SS in those two years. The 650SS was only manufactured in 1967 & 68.

If that is your motor, please provide more pics and I'll happily identify what is going on here for you.


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on December 29, 2018, 07:10:54 PM
Hi mercman .sn 2287548
has blu band but red 650 ss under that sticker
i think its at 50 years old its got bits of anything compatible
have put back together .found  a woodroff key ..pack 110 assorted
found 3x6.5x16 did the trick ( have ordered 2 x originals from states )
 cleaned up the surfaces with  valve grinding compound  cranked the nut to 75ft pounds torque and
relocating the belt back onto the gear on the flywheel was the hardest part
set the dizzy arrow to the flywheel timing mark .droped on the belt to the dizzy gear
turned it over a few times and it started and idles nicely
has throlle when given the diizy a tweet with linkege disconnected ....
will give it a crack
(trying to post pic s


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on December 29, 2018, 07:16:23 PM
65 hp

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on December 29, 2018, 07:20:07 PM
 dizzy and ignition (type 3 ?)

Title: Re: mercury 650ss 1967 4 cyl
Post by: Mark S on January 04, 2019, 12:22:03 PM
Happy new year to everyone on The Board.

Looks like the Dealer trick from the old days of making an outboard look like a later model. Also the engine block is painted black but should be silver. May have had a new Mercury power head fitted when it had the "blueband" makeover?

Black painted blocks didn't appear until the Blueband series. As the 4 cyl 65's  were phased out when the blue bands arrived, none would have had black blocks in their original format.

Mark S.

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on January 04, 2019, 04:34:20 PM
Thanks Mark
for its age its definatly had doner .parts
recieved the flywheel keys in the post ..they match the key i used exept for a slight flat on the back
they are basically the same .
tested on the water and running .fixed the key/ timing issue all good
starts well idols well . but back to the original problem of no top end
have pulled out jets and inlet s
cleaned and tested all leads and distributer cap  had a bad connection on lead 4
lubed greese nipples on the dizzy again
will try again ...

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on January 07, 2019, 01:27:24 PM
well it works- but im back to square 1
starts well idols well revs to 4800 at pier
but only 1800 under load
removed the plugs at home ..its running rich
but that could be that at wide open throttle alot of fuel is going in  at 1800 rpm they are fouling up
my hunt for the solution continues
more research ..
ive never checked compression but the past mechanic said good comp and good spark!
rectifier is good .maybe stator not enough power under load for hot sparks maybe
now i am definatly starting to nuts


Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on January 09, 2019, 05:46:33 PM
Are all plugs fouling equally?
Are any plug leads grounding out? Check for this at night time is best.
Have the plug leads been replaced by silicone? Should be good old copper on a '67 model, I reckon.  :-\
Is an ill fitting plug boot preventing a good contact between the spring and the plug top?
Pull back all plug boots and examine all connections.
Is belt out by one tooth?
Was timing conducted at WOT? Mark, am I right here, I don't have my factory service manual with justme right now.
Re-check compression. Never trust hearsay.


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on January 15, 2019, 08:26:06 PM
Thanks Mercman
cranked the outboard at night . no leakage
when i cleaned the dizzy i checked all conections at the boot and spring sparkplug end  ..yes copper wire
sanded all contacts and springs and rotor and dizzy to remove any bad connection .corrosion
checked for continuity with a tester ..cranked engine with a spark tester and all good sparks
checked tooth on wheel and belt .. arrow and timing dots line up like a straight edge was used
dropped it back a tooth  .. starts  idles .. timing mark on flash on cylinder 1 is right on 4 and line cast in top of castingPhoto i hope )
sticker could be wrong.....when arrow and marks line up ...idling on 800 rpm its timing at 4 - 6 deg on sticker marks
seems to be like they say in the manuals
any way  tes you are correct again Mercman 4 plug is cleaner than the rest
has signs thats its been fireing but its not as oily and fuelie as the others  yet its getting good spark
surface disgarge plugs ..inner coil is black yet the outside circle is clean ..the other 3 are burnt black
i laugh as i know that im now moving to another part of the engine arnt i ...
lack off fuel getting into cylinder 4 ... even though i cleaned the carbies ?..
Compression  ...ill check 

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on January 16, 2019, 04:15:37 PM
That is the incorrect sticker for a '67 model, if in fact that's what block you have??
That sticker belongs to a 73 model, which match your outer cowls. Grrr.
Where are you located? I think you have a Frankenmerc? I hate them.

As for number 4, I suspect spark, not fuel.
The bottom Carbie fuels both 3 & 4. Even a crook/bent reed would prevent 4 from receiving fuel.

Leave plug in 4 and place a grounded (spare) plug on number 4 lead. Start motor and check spark for strength.
Never start motor without pug in hole. Its starves piston, crank etc of oil, plus it will start a small fire at the back of the motor. Not a good look!