1956 30hp timing question

[pro-crastinator]

Hi all,
Yep, I'm new to the forum so be gentle with me.
My question is about setting the timing on my 1956 evinrude big twin 30 hp.
Yeah, I read all the posts and feel comfortable with the process but I have a question....
In an earlier life when I was tuning my 2 stroke twin motorcycle, I set the points using the position of the piston. It was set (as I recall) 3mm before top dead center.
When I installed my dial gauge indicator in top cyl on the evinrude and found TDC ? it raised more questions than anything else. It caused me to question how the ?wire from the points thru the ohm meter? technique actually works. - and how about the effect of the (I'm calling it by a name of my own invention) ? spark advance/retard lever thingie under the plate the points are secured to - That puts the timing all over the place ? My head hurts from overthinking this thing. I suspect that the "wire/points/ohmeter" technique will render the spark advance/retard lever irrelevant. Comments are welcome.

Anyway, Background on the boat/motor. Boat is a 1956 Whitehouse with a 1956 evinrude (model 25924) - which is in time capsule condition, kept on a shrine in a garage. The only evidence that there was ever fuel in the carb from visual inspection was the fuel bowls filter - which had an aroma of fuel. I am the second owner. Absolutely original in every aspect. Fuel pressure tank system way far gone. Built another and got a nice clean 16:1 mixture to feed to the carb at around 4 psi. Started the engine and got it to run by holding throttle ?lever? away from idle ? to run position (air silencer removed). COuld not get it to higher rpms. Was told it last ran in 2001, so I'm moderately happy so far. Carb rebuild kit and points/condensors and impellar are in the mail now. Saw spark on both cyls and am presuming coils are ok. ( if it ran, something s gotta be right?) Time will tell after carb rebuild and ignition parts go on. Hopefully it wont be too cold.

Thanks.

 

[kfa4303]

Re: 1956 30hp timing question

Hi pro. Welcome to iboats. Cool old mtor you've got there. Well worth the effort to get and keep running. As far as your timming concerns, these old girls are great, the timming is actually set mechanically by sinply aligning the flywheel properly. From there, you simply set each set of points to .020" using a feeler gauge wuch that when one set is fully opened, the other set is full closed, thus creating the alternate firing pattern. The armature plate the coils and points sit on is mechanically rotated counterclockwise when you twist the throttle causing it to move in the opposite direction of the flywheel, which rotates clockwise. As a result the coils pass by the manget on the inner rim of the flyhweel more frequently, thus increasing the rate of spark. At the same time the butterfly valve of the carb is also mechanically opened to allow for more fuel/oil mix into the cylinders. Between the increased fuel, air and spark the motor runs faster. Here are some great links tpo help familiarize yourself with your new toy. Feel free to ask lots of questions. You can get any routine parts you may need right here at iboats. Holler if you get stuck. We love pics too

Reviving a Vintage Big Twin - Part 1
Magnetos
3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967 (for a different model, but all the steps are the same for your motor thanks to the good ol' OMC Universal Magneto)
5.5 HP Evinrude Johnson 1954-1954 Carburetor Tune-Up Procedure (great carb rebuild link. Again, for a different model, but all the steps are the same)
Vintage Evinrude Johnson Outboard Parts & Diagrams - Catalog ITEM_2750

 

[HighTrim]

Re: 1956 30hp timing question

Well where is the eye candy!?

If the coils are original, and the motor hasn't been wrenched, they will be NFG and will need to be replaced, even if they are providing spark on the test stand. They will fail on the water guaranteed.

Something to note. This motor was originally setup to run on a 6 volt system. If you plan on running it on 12 volts, you will need to modify the wiring and replace the choke solenoid and starter solenoid. The starter will handle the 12 volts ok. I can post the wiring diagrams if needed. Another option is to wire in an ignition resistor. I did just that on my last conversion. They are readily available. This drops the voltage down to a safe level for the choke solenoid and mercury switch. (knock on wood I have never yet had an issue hitting the mercury switch with 12 volts)

It is irrelevant where the throttle is positioned when setting points timing. The best tool to have is a timing fixture. F_R on this forum makes them and I have one made by him myself. It is used in conjunction with a meter. What you want to know is when the points break, nothing more. You want them to break when the fixture is aligned with the first hash mark for new points, in between the two hash marks for used points. Setting the points timing in this fashion ensures that the points break at the exact time, AND that they fire exactly 180 degrees apart for smooth running and idle. Been a while since I have used my feeler gauge.

 

[pro-crastinator]

Re: 1956 30hp timing question

couple pics. Its "open" so it aint as pretty as it can be!

New 6 volt battery is doing fine. Napa commercial. group 1. No re wiring desired here. We wont worry about the funky mercury switch on the throttle.
Ordered new coils just now. Napa will have them in tomorrow. Thanks for the heads up on the coils, how do they look to you in the pic?
Points, condensors, carb parts and impellar just arrived today.
I will put away the dial gauge and get it done with the ohm meter.

Thanks again. Stay tuned for the drama to unfold !

 

[HighTrim]

Re: 1956 30hp timing question

Those are not original coils, they have been swapped at one point. They are from the early 70s I believe. May be just fine, test the secondary winding. To test run an ohmmeter between the spark plug lead and the coil ground lead and let us know what resistance you get. To test the primary, test between the ground lead and the lead to the points. Should bury the needle.

The condensors and points have been changed as well.

 

[HighTrim]

Re: 1956 30hp timing question

here is your original wiring diagram.

 

[pro-crastinator]

Re: 1956 30hp timing question



couple more pics. put the cover on for pic but not screwed down.
water intake port exposed for tank test - as directed by owners manual.

 

[nwcove]

Re: 1956 30hp timing question

couple pics. Its "open" so it aint as pretty as it can be!

New 6 volt battery is doing fine. Napa commercial. group 1. No re wiring desired here. We wont worry about the funky mercury switch on the throttle.
Ordered new coils just now. Napa will have them in tomorrow. Thanks for the heads up on the coils, how do they look to you in the pic?
Points, condensors, carb parts and impellar just arrived today.
I will put away the dial gauge and get it done with the ohm meter.

Thanks again. Stay tuned for the drama to unfold !

View attachment 219178View attachment 219179

my eyes could be deceiving me, but in the first pic, it looks like those points are open.....way to soon?

 

[HighTrim]

Re: 1956 30hp timing question

Looks clean! Great find.

That is the intake for reverse. The scoop aft of the prop is the main intake. Im sure it helps to remove the grate for tank testing, never done it myself though.

 

[HighTrim]

Re: 1956 30hp timing question

my eyes could be deceiving me, but in the first pic, it looks like those points are open.....way to soon?

You have my craning my neck at all sorts of odd angles, lol

 

[nwcove]

Re: 1956 30hp timing question

lol Chris....now im moving my lap top at odd angles! guess its time to head to lawtons and upgrade my reading glasses!! but im sticking to my story!! looks like the points are open more than 0.02 and they have a ways to go before the top of the cam lobe! lol

 

[Chinewalker]

Re: 1956 30hp timing question

About the only thing you may want to do to tweak the timing is to set one side to .020, then set the other side to open at EXACTLY 180-degrees opposite, regardless of what the gap ends up being. Use your piston depth gauge to find where the first set first cracks open, then set the other side to open at the same point, 180-degrees apart. My Dad raced that motor in 36-Class Utility Stock Outboard back in the 1960s and that was one of his tricks...

 

[HighTrim]

Re: 1956 30hp timing question

Or buy Franks timing fixture. It is one of my tools on the "quick grab" shelf.

Frank's Tools

 

[tomhath]

Re: 1956 30hp timing question

Hi all,
When I installed my dial gauge indicator in top cyl on the evinrude and found TDC – it raised more questions than anything else. It caused me to question how the “wire from the points thru the ohm meter” technique actually works. - and how about the effect of the (I'm calling it by a name of my own invention) – spark advance/retard lever thingie under the plate the points are secured to - That puts the timing all over the place – My head hurts from overthinking this thing. I suspect that the "wire/points/ohmeter" technique will render the spark advance/retard lever irrelevant.

There should be timing marks on the flywheel and cam (the "thingie"?). Here's a picture of my 1963 18HP motor, when the piston is at TDC and the mark on the advance is at the cam roller all three are lined up (flywheel timing mark, cam zero advance mark, and cam roller). That's where I set the points to open with the ohm meter. Setting the gap to 0.02 makes them open very close to that point. Make sure the throttle linkage is adjusted to just start opening at that mark too (carburetor is off the motor in this pic so linkage is not pictured).

 

[pro-crastinator]

Re: 1956 30hp timing question

wow. great information. Thanks one and all.
Its raining today and I am waiting for a dryer day to start on it.
gimmie a week and I'll re start - with another round of questions.
thanks again... stay tuned.