1957 Evinrude starting problem

[spitz]

Re: 1957 Evinrude starting problem

Question.<br /><br />When I set the timing with an ohm meter, should I only have closure (0 ohms)of the points when the timing mark on the fly wheel is only between the armature marks? I seems if I move the flywheel counterclockwise passed the armature marks the points are still closed (0 ohms). When I move the flywheel clockwise passed the second mark on the armature the points open before I am outside the mark.<br /><br />Hope this makes sense.<br /><br />Need clarification.

 

[Paul Moir]

Re: 1957 Evinrude starting problem

No, the points should open (go to infinity from 0 ohms) somewhere between the two marks when you're rotating the flywheel clockwise. Ideally, it'll happen half-way between the two.<br />On magnetos, spark timing is governed by when the points open rather than close. They also need to be closed for a fairly long period before they open. Don't worry about that though - it's designed into the cam.<br /><br />For what it's worth, I've found the .020" gap to work just fine for some Jonny/Rudes and gets the timing deadly-accurate, but it'll be pretty far off on others. I always follow up with a timing check after setting the gap like these folks are suggesting.

 

[Chinewalker]

Re: 1957 Evinrude starting problem

Hi Spitz,<br /> If you've set your points at .020" with the fiber rider of the points aligned with the crankshaft keyway, the motor will run. I think your problem lies outside the realm of timing. Using ohm meters and such to set timing is more of a fine tuning measure. Those old Johnrudes are some of the most forgiving motors out there and will run quite well with a simple points adjustment to .020 without any fine tuning at all.<br /> I believe your problem lies in your compression. 65psi is definitely on the low side. Ideally it should be 80 or above. It might run with that, but it would certainly be hard starting. You mentioned you have the exhaust port cover off - are all three rings on each piston free floating in their grooves? You should be able to take a wooden pick and move each ring just enough to visibly spooge oil out of the ring groove. The fact that you can spin it over with a drill tells me that it's not putting up much resistance. <br /> A decarboning might help bring up comression a bit, but I suspect a partial rebuild is in order. New rings if you can find them, but certainly a light honing to true up the cylinder walls a bit, and agood cleaning of the ring grooves might do the trick.<br />- Scott

 

[Paul Moir]

Re: 1957 Evinrude starting problem

New rings, if you end up looking:<br /> NY Marine, Click here. <br />They're a little pricey, but they're in C$.