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63 65 hp mercury 4 cyclinder

W

Wayne Bahr

Member
i cant get it to start unless at full throttle then wont idle took it to a shop they said has erratic spark and something about replacing the magneto but didnt have part or want to work on it any advice
 
Remove 4 bolts and remove the lower part of the magneto.------Put it on the bench and take off the distributor cap, etc.---------Work carefully as these parts are available but quite spendy.------Clean and set points at 0.008" to 0.010"---------Test for spark before re-assembly by spinning it by hand or even a drill.--------There should be a small lightning storm if everything is correct.--------Note , plug wires are screwed into the distributor cap.
 
racerone said:
Remove 4 bolts and remove the lower part of the magneto.------Put it on the bench and take off the distributor cap, etc.---------Work carefully as these parts are available but quite spendy.------Clean and set points at 0.008" to 0.010"---------Test for spark before re-assembly by spinning it by hand or even a drill.--------There should be a small lightning storm if everything is correct.--------Note , plug wires are screwed into the distributor cap.
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sweet i will give it a try appreciate the advice i took it to a shop and they charged me 40 bucks to tell me it doesnt have start or spark right when already new that just said something is wrong with the magneto and they didnt want to work on it
 
First you take the bottom of the distributor assembly off ( 4 screws that require a 3/8" wrench ) and then you put it on the work bench.-There is no need to take the distributor cap off untill it is on the bench as an assembly.---Then you will see the screws for the cap.---Do not force any parts as this stuff is expensive if you break any parts.----------This is fairly straight forward work and there are no traps waiting to spring on you !
 
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yeah i got it off i already broke a part i will have to replace but i dont know how to get to the points when i spin it it does something cause it shocked me but dont know how much
 
You take the distributor cap off , then rotor , then a cover and you will find the points.---Work carefully parts are expensive.
 
i got all that off broke the rotor but dont know what the points are all under is the rod with the little strips around it rubbing against it
 
Go to ---------------mercruiserparts.com------------Put in the information ( serial # ) that you have and look up the parts.------------You could also try ----eastcoastmarine -----------specialize in older mercury parts.-----More scources as well.-----------I have a 63 , 64 and also a 66 model that are similar to yours.
 
yeah i found the part had to be the expensive one i broke but still dont know what the points look like or how to set i know i got somekind of spark cause it shocked me
 
The shaft that rotates has a 4 lobed cam on it ----------The points are opened by this cam as the shaft rotates.------------Over time the block that rubs on the cam lobes wears and the points no longer open the required amount.--------------Set points with feeler guages.---------Points must be absolutely clean !
 
Like I said go to those websites and see what " points " look like.-----------Lots of pictures posted for you to learn about this old reliable stuff.----Points are also called " breakers or breaker sets " for those who want to learn.
 
Sorry , but the point gap is not set on the cam or the rubbing block.----------------The wee round contacts half way between the rubbing block and the pivot point of the moving arm is where you set the point gap.-------------Work carefully before you make expensive mistakes !!-----Perhaps there is a tutorial on U-tube for you to become more familiar with this type of work.---Search for it.
 
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downsized_0423121809.jpgyou cant see it very good but i dont see any round anything in between the rubbing block and contact point or know how to adjust it
 
Set the points at 0.010 inch open at the top of the cam, then spin test the mag with a drill. If you see a bright blue spark 1/2 " long, reassemble everything and go boating. If not...get back to us.

Jeff
 
does the real manual have better pictures of the points? i baught a downloadable one and doesnt have anything but some crappy diagrams and parts lists
 
Go to the search engine called -------Google -----------Type in " ignition points gap "-----------------All the information you could ever need at your finger tips.
 
i set the the points and i can see the spark but its not that big of a spark and had to be in a dark corner and get the drill spinning it pretty good is that normal or could there be something else wrong? it will spark enough to shock you just by turning it but cant see the sparks unless the drill is spinning it pretty good could that be whats going on why could only get the boat to start and run at almost full throttle?
 
Spark should easily jump a gap of 5/16" or better ----A small electrical storm so to speak.----------------If it does not then magneto components need more testing.
 
ok thanks will take it apart and clean it better yeah parts are expensive i got a new rotor and the capacitor thing on the way and new spark plugs and wires guess if it doesn't get enough spark after that will just buy a new coil and points and don't think there is anything else in there that could be the problem i found the cheapest place was oldmercs.com they had my rotor for 130 and every other place wanted 200 hundred plus it will shock you pretty good by just turning enough to make you not want to stick your finger there again just by turning by hand i could see the spark was about a quarter inch in diameter but only when i had the drill spinning it pretty good speed.
 
A lot depends on your location.---------Was at a dealer where they were dumping near complete motors like that in the dumpster.-------No call for them.-------No one want to repair these things any more.-------Too much bother to salvage parts that no one wants to pay decent money for.-----They need the room for new stuff !
 
thanks for all the help been much appreciated if this doesnt work after i get parts guess i get a coil and new points and should take care of it i hope you got any advice for setting the idle on the carbs? when i baught it the guy said they wernt synchronized right so didnt have full power
 
Have you examined the motor carefully ?-----Done a compression test ?------------Pulled the bypass covers to inspect pistons and rings ?--------No point spending time and money on a motor that is not in good mechanical condition !
 
no but it started up good and ran good when i baught it and it was wierd cause it started right up a few weeks ago to with a hose on it and then took it to the lake 2 weeks later and it didnt want to start unless at full throttle engine sounded good everytime even at the lake it just would stall this last time if i dropped it down to a idle
 
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