35hp mercury no spark

[stuandamy]

hi guys i have a 1964 mercury s/n 1629706 35hp motor with pull start, my problem is that i have no spark i have checked the wiring,installed new plugs and points had the coils checked and the are ok can anyone help me out??

 

[Laddies]

Re: 35hp mercury no spark

disconnect the two wires that come to the wiring block on the side of the engine to set if the problem is under the flywheel or in the wiring, mercury switch and etc. if you still don't have fire ck. the wiring under the stator plate and your work

 

[Chinewalker]

Re: 35hp mercury no spark

Hi Stu,<br /> I had one of these awhile back that was a real head-scratcher. Turned out that someone had replaced the screws that held the kill wires to the nylon terminal block with longer screws. They went right through the terminal block and grounded out against the motor block. They guy I had gotten it from had installed new ignition components, waterpump, etc. and gave up on it. I replaced the screws and it ran like a top!<br /><br /> As for yours, if that's not the problem, it's time to methodically work through the system. The weak link in those ignitions is typically the condensers, as the coils tend to be quite sturdy, and you've already replaced the points (gapped at .018"?) On those Mercs, align the keyway with the contacts of the points to gap them (I think - working from memory here). Make sure the points are clean, too. Try running a file card dipped in lacquer thinner or carb cleaner through the points.<br /><br />- Scott

 

[stuandamy]

Re: 35hp mercury no spark

thanks guys will check out your suggestions tomorrow and see what works, fingers crossed.<br />regards stuart

 

[stuandamy]

Re: 35hp mercury no spark

hey guys back again tried all your suggestions but still have no spark????<br />does anyone have any other ideas <br />its got me stuffed and very

 

[stuandamy]

Re: 35hp mercury no spark

what are the chances of it being the flywheel? do they stuff up at all, visualy it looks fine though

 

[Chinewalker]

Re: 35hp mercury no spark

Hi Stuandamy,<br /> Did you replace the condensers with new of the correct type? <br /> Another thing to check... Have you had the flywheel apart? The magnets are indexed to the keyway on the hub and if the flywheel has come apart at some point, the timing could be off enough to not allow spark.<br /> Are the points SPOTLESS? Run some 400 or 600 grit sandpaper through them, then clean them with an index card. After than, spray them with laquer thinner or carb cleaner to remove any residual oils.<br /> One other thing. I've seen some of these that needed a ground strap from the armature plate to the motor block. Sometimes the grease and such can insulate things too much and cause problems. Try running a wire from one of the condenser bolts, under the plate, to the motor block....<br /><br />- Scott

 

[stuandamy]

Re: 35hp mercury no spark

back again, tonight i pulled the fly wheel apart and lind up the key hole with the magnet and guess what, i now have spark on #1 plug but not #2, i tried going either way an extra hole on mounts for flywheel only result was to lose spark on #1 again so i returned it to my mark where i had spark on #1. now can anyone give me another idea pleeeasseee. both plugs and points are new have even swaped them over with same result, also had both condensers rechecked and they are fine.

 

[stuandamy]

Re: 35hp mercury no spark

problem solved, last night i pulled the flywheel apart completly and disconected all the electrical system and cleaned everything and started from scratch. wouldnt ya know it had spark on number #1 but not #2 played around with the flywheel a bit more and bingo now she's firing on both cylinders just need to put her in the tank to check out if timing is right (cant see why it would be out though). <br />thanks for the ideas folks,<br />regards stuart