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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!

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on January 22, 2019, 01:37:00 PM
THanks Mercman
done that spark constant on plug lead 4
plug firing
sunny bayside  moorabbin
didnt get to water on weekend . will try asap
its not over till its over

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on January 23, 2019, 02:05:40 PM
One of our members AaronJ had a collection of 4 (I recall) of short shaft 650's. Perhaps he may still own a goer which he is prepared to part with? Send him a PM.
If need be, I can email you his phone number.


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on February 03, 2019, 03:20:20 PM
thanks for that reply Mercman
been a week or two now .  sorry
ive done this and that   done some more research
yep its a frankenstien its just guess work
it could have a 50 hp powerhead on it putting plugs for a 65 say l17v may not be right as the 70s model runs a l77v plug
the timming for a 1969 650 is different from a 1972 model
mine seems to be made up of parts from 67 - 73 so its trickyim across the road from the guy i bought it off . he said it had rings and a new top where the plugs go in  done about 4-6 years ago buy someone out of town
hence why its got good compression
as i said starts idols revs  but only to 2 2000 rpm underload.after injecting copious amounts of carbie cleaner down carb 2 my forth plug seems to be getting fuel oil .as is wetter than before and i used a different plug so i think we are on all 4 cyliners.
so this brings me to the prop . i have the original as a spare buts its stuffed ,has the numbers on it  mercury original 13and ? x 15 pitch
found tables with prop sizes and pitches for  65 hp from that era
i cant tell what ive got on as i cant find any id numbers ..
i should have a 13 .5 x 15 lets say .. different prop pitch and size for d``ifferent revs of the same engine 
it says that a 13 will rev to 4800-5200- but a 14 with some ?inch pitch ..which is designed to push a houseboat will rev to 2800 but have heaps of push
so maybe ive got a bloody houseboat prop and nothing is wrong with my unit!
so i stopped at a mercury parts shop and enquired about buy a correct prop  for $200-300 willing to give it a crack
and the guy says "reckon your wasting your money .youve got other issues and didnt even offer me a prop ...
so i have finally decided to give it away . i give in . i cant afford to buy anew 60  at 8 grand ,but i dont want to buy somebody elses second hand 20 year old piece of ??? that they want half the original price for out of gumtree or ebay ..ive learnt my lesson
just because it starts and runs doesnt mean its a good outboard
a friend of a friend ended up being a mercury outboard expert . he loaned me the flywheel remover and a compression tester small enough to get to no 4 plug
 comp is good all 4 around 120 psi  and even 
anyway stuck with a no go boat ..thinking of giving back to the guy i bought it off ($1000.00) and and telling him to keep his money and have his boat as im over it  luckely it was more time than money spent  :D :D :D
lessons learnt 

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on February 04, 2019, 06:19:31 AM
Not only could the prop be a factor, you may have a gearbox with the incorrect ratio based on what ever powerhead you have.
Sent us a pic of the gearbox plus the midsection and shockers (if any). These pics will assist me in figuring out the possibilities.

This is a good quiz!


Title: Re: mercury 650ss 1967 4 cyl
Post by: austral on February 07, 2019, 06:54:12 AM
Are you 100% sure you are getting full throttle ? The fact its been swapped and changed, it may not be adjusted right.

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on February 10, 2019, 12:05:56 PM
made a tank

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on February 10, 2019, 12:44:02 PM
Hi . great thinking and good theory s
but being the fact that i have video of this engine wot and up on a plane ,3 minutes before it stopped
it coughed a bit ran a bit and coughed and died .  which we have found out to be the flywheel spinning and shearing the key. no start again
and i dont think it sheared the key due to a sudden lock up stop !i died slowly so i asume it was due to incorrect torque setting on flywheel nut .not tight enough
and the guy i bought it off ran it in this configuration before me . with this prop ...he did admit that i didnt go as hrd as it did after i tinkered and lubed the dizzy magnito thing ( 1 st post )
so ill push reset ( wish there was one ).and go back to the start .chapter 1 page 1 and with a fresh head
 check voltages . sparks . can now check timing in gear at idle  ( im suspecting timing still  rememering 2 mechanics have both suspected timimg )
i l do a link and sink  checking that
mercaman thanks for your input ..
im working on a 4-6 deg atdc idle  38deg ithink wot
but other ignition setting for like wise engines seem to be all btdc?
the plugs firing before it reached tdc  understanding it advances as the revs increase to pre anticipate the the next time to fire
but still weird some are before .and a few are after ..or am i wrong and my timng settings are wrong
and sorry mercman there is no showcase or mercedes benz after this quiz if you win , but i will sell you my 1969 280s ( 2 50 year old headaches that both start with m)

Title: Re: mercury 650ss 1967 4 cyl
Post by: austral on February 12, 2019, 07:49:20 PM
Water leaking around spark plugs and shorting them out ?

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on February 13, 2019, 09:06:51 AM
The loom in your most recent picture doesn't look real flash. It shouldn't look limp like that (near the support bracket).
Take the electrical tape off and look for perished/damaged insulation of the wires within the loom.
Can you borrow another control box and loom assembly from someone? (I had spare control boxes up until this time last year.) Try speaking to Guy at the Outboard Workshop - Carrum Downs. I sold most of my collection to him.

This is an obvious one... is the vent on the fuel tank open, since attending to all the other suspects?

The other thing I see in the pic.. That's not a 1967 outer. This leads me to think the position of timing mark (decal) is probably not matched to your powerhead. This needs further investigation, only if there is nothing wrong with the wiring within the loom. 


Title: Re: mercury 650ss 1967 4 cyl
Post by: Mark S on February 13, 2019, 12:23:09 PM
I've read everything and you've gone around in one big circle. Need to start from basics again. Mercman's point about mis-matches needs to be kept in mind, it may or may not be contributing to the problem.

Have you checked number one cylinder piston top dead centre to see if it matches the TDC on the label before checking ignition timing? Timing should be checked at max advance which is 32 degrees for a 1967 model. Can be checked at any revs or static.

Don't let a clean spark plug on the bottom cylinder mislead you either, some in-line Mercury's do that.

If you had a houseboat prop on it, it would be revving its head off and getting no-where, not loading up.

Obviously you are using a good brand of fuel like BP and a quality 2 stroke oil like Mercury premium plus or Evinrude XD30.

I would think a 15 pitch prop is not too big, your gearbox should be a 2.1-1 ratio.

When under full load, have you had anyone squirt some fuel in to the carburetors to check for fuel starvation?

Can you post a photo of the spark plugs, so Mercman and I can see them.

Mark S.

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on February 15, 2019, 07:19:55 PM
thanks -Austral,Mercman and thanks Mark
Water in the plugs would mean .. in the water at dock reving to 3-4000rpm   waterpump pumping hard would maybe  give me ,missing or lumpy rpm ..not getting that . it revs clean to 4800 under no load ..( i may be wrong )
in the first week-  i opened a can of worms by opening controller  , total re wire as it was all stuffed . water had got in through choke button and all the wire had perished and corroded . all redone  .tested from controller to conections inside the engine therefor testing the loom and black external plug and internal wiring loom for continuity and voltage with a multi meter  .but i will check that loom end again 
vent checked...... i recon every time i  try it ( isnt that the first sin ?)
timing mark lines up and piston top dead  center .. visited that at the time of the flywheel re install and  yep ill re check that
Marks correct.the houseboat prop would still rev ..i didnt read some pdf i found correctly. Information overload
no havent squirted fuel in under load ... and im  using good fuel and oil ..had 91octane  and tried 95 .( which is better?)
i have not tested in the water for 3 weeks. so i should try it again  before i pull it all apart
i have missed something. ive just got to find it

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on February 17, 2019, 02:20:22 PM
sunday morning .bays flat .slipped it in. idle , ;D out trim it in.....go ! up .up up . slowley revs increase .and we are now ....plaining   ;D
check tacho , 2800 2900 3000 3100..wot played around with trim and had me and mate jumping around up front trying to increse rpm by weight distribution
but moving and plaining    But it was fun ! finally after 1 year i got it to move along
aadd some chop and swell and its probably back to useless again! but is is a positive .(Frankenstien phsyco engine you a little bit of improvement just to keep you hooked )all it had to do was rev to over 4000 rpm under load !and i would have spent  money  replacing any part with any new parts i could find
on the web .slowley week by week .
Im thinking now ,, becuase i fixed it this far ..of finding another mechanic  drop it off and say nothing of my past history
" i was out last sunday mate and its was not reving over 3000 rpm ..strange hey " and leave it with him  :D :D :D :D :D :D   ::)

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on March 03, 2019, 12:44:03 PM
 used it a few times .
dreaming of a new outboard 4 stroke @ 9100.00 just goto come up with the cash
 also decided to get new stator . under flywheel ,new internal loom and new leads and boots cost around $600 all cdi
if it doesnt fix it ill replace the switch box with cdi replacement around $300 .
timings good link and sink goodstill reving max at 3100 and plaining, so im chasing 2000 rpm .( have voltage fluctuation up and down )
have two rectifiers and both ok so ?
gets me out and back at the moment so im content , at least i have caught a fish .
time has come to start throwing some dollars at it ( parts not  mechanics )

Title: Re: mercury 650ss 1967 4 cyl
Post by: MERCMAN on March 04, 2019, 08:48:06 AM
Don't wast your time and money on a gutless 4 stroke.

In the particular hp range you're are looking at, you can't go wrong with an Etec. That is honest advice coming from a Mercury fanatic of 57 years.

An Etec's first service is due at 300 hours. Try that with any 4 banger and see what happens!


Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on March 11, 2019, 06:47:33 PM
advice taken thanks mercman
new yellow leads and ,disy and plug boots  and new springy connectors should land from states in the next few days .$90 and $30 postage roughly
last  run i adjustedthe idle jet screws and idle stop on the water in gear . was idling low nicely but after sitting for an hour that setting wouldnt start very well
so i ran both screws back in and then 1 and 1/2 turns out and bang starts in a flick of the key so ill leave it at that. whilst doing so and playing and tinkering with stuff while its running under load with a friend driving ( bay was so flat ) i got a zap
off something around the dizzy- throttle linkage area .  i did run at night to check in the dark to see a short or spark leakage  but it was in drive on muffs with no load . and nothing . so hence get new leads first .. if no change then stator /alternator

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on March 24, 2019, 08:31:36 PM
new leads and boots arrived last week . .fitted last weekend and took it out today
no change but i did catch a fish!
new cdi Stator ordered and payed for yesterday ....on its way from the usa again
charging circuit only puts out 12.4 volts , i believe this is the problem ,but i have just been avoiding it  probably due to its cost and availability
tested it at wot on the bay this morning .same reading as in the driveway idling on muffs
already replaced the rectifier

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on April 06, 2019, 11:10:16 AM
i can tell you that pn 174 4793 stator doesnt fit my engine . doh
need part 398 2997. for sale 1 stator
maybe i can get the original rewound ?

Title: Re: mercury 650ss 1967 4 cyl
Post by: antman on April 15, 2019, 03:36:08 PM
returned stator (amazon)
found the right one .new old stock  $93 dollars . paid but no email conformation ..i doubt ill ever see it !
very hard to find
found a rewind guy . can do it for under $200 . he tested it and said it was good
i told him it was only doing 12 volts .. under his calculations he said it would ONLY do 12 v
i said it should be doing over 13 -14 to charge the battery ? am i wrong ?
found one on ebay second hand for $170 from states . he said to ask for a resistance . mine is at 0.6 ....if its the same ,its not worth getting he said .......
any ideas
(tried to post photos many times but they are to big? and never get through)