TOPIC: 1968 Chrysler 55hp Coils Question

Recently aquired another project Chrysler, this time a '68 55hp 5561 with battery ignition rather than under flywheel coils. This motor has unknown history. It has no spark, so I pulled the flywheel and cleaned and setup the points - still have no spark and I wondered whether the coils have failed, but will go back and run through the tests - I don't have a coil tester though... If it's viable I'll spend money on new condensers and points, diaphram and water pump. But, I did find some spares I got from a dealer that retired - 2 blue 12V coils like those on the motor and 2 black Motorola coils that look the same size, p/n 70C44882B02. Are they inter-changeable (the net seems to show only 70hp) and reliable? I have a factory manual for the 35,45 and 50 - I assume that the battery ignitions are all the same? This is a pic of my '74 45hp Magneto restoration.

Answered my own questions. Useful resource in couple of manuals on boatinfo.no. The black coils are CD ignition coils with .22ohms on primary windings and 532ohms on secondary. Parts for these motors are eye-wateringly expensive these days. Guess it comes with the NLA territory.

CD coils are as you found very low in resistance. Not to say you can not use breaker point coils on CD boxes it has been done for years in the car world. Its just not optimum. A battery ignition coil is going to be around 2 ohms or so and a coil with an internal ballast resistor a bit higher. At 2 ohms the coil current would be 6 amps! (12 V/2 Ohms) So a current limiting resistor (ballast) is in the circuit (while running) to limit this to some more reasonable current, like 2 amps. Otherwise the points would be toast quickly. You can see that using a CD coil would shoot the current way up (20A?!!!) and something would smoke. Also these low resistances are about imposable to measure with a modestly priced typical DVM. The difference in 2 and .5 ohms is tough to discern, looks like a short.

Parts for some of the low volume versions of the points mags are scarce. The way we usually run these as in not a lot, if you get a good set of points new or used and take care of them. Lube on the cam, good condensers so the contacts last, inspecting them often to catch if a condenser is going bad. They will last a lifetime of occasional hobby use.

For my 105 hp 4 cylinder I substituted a MSD Street Fire for the original Motorola CD. It made a burnt offering.

I am eventually going to get a two cylinder Chrysler and I will look into substituting some points like the dead common OMC mag points. I am betting it can be done with a little machine work.

Another fix is (since electronics is my bag) a little add on board for battery point coil ignitions, an electronic switch that takes the high current off the points so they last as long as the rubbing block will. These circuits are simple and were all the rage back in the day for cars.

And one last thing that I constantly preach. Never leave a plug wire loose, it should be on an installed plug or grounded by a clip-lead (or other device). In most factory manuals this is mentioned. The reason why is that an open secondary in the coil causes the voltage to spike high and will damage the coils wires caps rotors. That voltage will find its way out somewhere. It may not cause trouble right now but you are setting up for a failure later. On CD ignitions the spark voltage and current is a lot higher so its even more important to ground your plug wires if they are off the plugs.

Thanks for the help & tip re grounding the wires. Mine will be run for a few hours a year, so I'll care for the points - have bought new condensers and will pick up some spare points too. Didn't realise they were so scarce, so let us know if you come up with a usable OMC set/design. It has an aftermarket / home made rectifer that looks like it's been cooked too...

Nice job on that 45 hp. looks sharp. I have also used automotive coils on the 12 system. Ballast resistor with a straight shot from the starter relay. I have 2= 55hp a '75 with 12v ign and a 73 with mag.Both long shaft. I am looking for a 75 or 85 hp long shaft to replace the 55hp on my clipper. Just need another 20 or so hp.

"A battery ignition coil is going to be around 2 ohms or so and a coil with an internal ballast resistor a bit higher. At 2 ohms the coil current would be 6 amps! (12 V/2 Ohms) So a current limiting resistor (ballast) is in the circuit (while running) to limit this to some more reasonable current, like 2 amps. Otherwise the points would be toast quickly."

198tpi,

Sort of jumping the thread here, but I've always had a question about ballast resistors.
Why can't the primary circuit either have decreased wire size, increased length, or increased turns, to reduce the current flow. The result would be the same as adding a resistor in the primary circuit. Granted, if the primary winding turn number was increased you would have to increase the secondary turns to keep the turn ratio the same.
Or why not find a coil that has a primary resistance of 6 ohms so the running amperage is 2?

Don

Flyingfish, No worries about jumping the thread, is a interesting topic.

1030hugo, thanks for the compliment. It was a personal challenge to learn a new motor. Chryslers sure have many ignition setups with the model ranges, but the engineering is very simple. I've been hunting for a pre '65 West Bend 50 over here, without much success, but I do enjoy the cowling styling of them.

For eons GM used a resistor wire from the ignition switch to the coil. A wire made from an alloy like nicrome that has a large ohm/foot rating relative to copper. I suppose that was cheaper than mounting a resistor separately. BTW the resistor in the coil thing is a big compromise, there is no way to bypass it during starting.

Having installed new condensers, an impeller and refilled the l/u I tried to start the 55, but the motor backfires without starting. I don't know it's history either. Which leads me to a potential timing issue I think. I've checked the timing with a dial guage to 32deg BTDC or 0.281, made sure the full advance marks line up and checked and rechecked the points to .020 (per the breaker plate's marking). Idle jet is one turn counterclockwise.

Excuse me if I sound ignorant here, but I'd always assumed that, on a twin pot motor, one set of points closes before the 180deg set opens. In my pic both are open at a certain point with the other set just about to close as it comes off the cam. My question is this normal?? There seems to be a long section of the cam which is a high point - this motor has no mark on the cam - and I ask whether I am getting the right point to set the points, i.e 10deg on from that 'high' point?

Have you fixed this?
I cant help but wonder if this motor has had a CD to battery coil conversion done on it. What is the model #? I cant help but wonder if this is a mix of parts from two motors and if that has knocked the timing off. So you checked the points opening point in distance below TDC on both cylinders?

Here is a pic of my 45hp Magna Power version. Same setup minus the condensers.

If you have not fixed this yet I will go pull the flywheel of this one and get a better pic of the cam for comparison and note the cam position relative to the crank key, where TDC is, points position and so on. For comparison.

Since my 'bag' is circuit design I have been tempted to make a universal CD box for outboards, and of course it would work on other stuff. It could go for less than one of those 'blue' Prestolite boxes, but work on any setup.

Note to self: read what you previously wrote on a thread.

The battery-coil and mag points are set to .020 thousands and the CD points to .015. On the highest part of the cam.

No, not fixed yet. Pulled the flywheel today again and took some more pics below. I've set the points to 020 at the position shown in pic 37, yet in pic 36 you can see both points are open.. At that point the RH set are about to fall off the high point of the cam and the LH set are just about to open fully.

Model number is 5561. Did they have CD ignition on this model then? One of my manuals (Technical Publications - 30hp > till 1969) only mentions magneto or battery with alternator). I don't know anything about it's history, so the 'monkey wrench' team may have already got to it. Not knowing much about these models, I am quite confused; despite having a couple of factory manuals at my elbow.

Just a thought though - there are 2 different sets of points for these. It's possible the incorrect set were fitted before...

To the best of my current knowledge the two sets of points are for different systems. Fairbanks and Wico mags. The Fairbanks mags I have seen are on basic rope start no alternator motors. The same points are used in the mags and as triggers in the Wicos. When I get time I will do a little digging and double check. Your points look to be the right ones. And no I don't think West Bend/Chrysler had any electronic (CD or not) in the late 60's. I know Mercury did at least by 67, I am not sure when Chrysler started 72? 73? But it is easy, say to put a 70's points triggered CD system on a early motor.

I may see the issue here. You need to set one set of points at a time. Set one follower on the center of the highest point of the cam, then set the gap to 20 thousands of an inch. A light drag on a .020" feeler gauge. I use a go-no go method, flip out the 19,20and 21 thou, 19 should be loose, 20 light drag, 21 no go. Roll the crank around till the 2nd rubbing block is on the high point and set that one the same.

The spark always happens on the break of the points. Battery coil ignitions limit the amount of energy consumed by limiting the time the points are closed, or 'on'. With one set of points/coil per cylinder there is plenty of time to 'charge' the coil, So only closing the points for a short part of a revolution is normal. Unlike say single coil distributor ignitions on 8 cylinder 4 strokes, (or two stroke fours) which start crapping out around 4 grand. Even by keeping the points closed as much as possible.

After you get this running as is. I can post a cheapish and reasonably easy electronic conversion you can do. The points will last till the rubbing blocks wear down to where you cant set the gap. And spark will be much hotter, not CD levels mind you but like the cars made since the 80's.

Thanks, opened my mouth too soon re. the points. However I did do a detailed check of your stator and another I came across (assuming it was timed correctly) in order to check settings (I see I am missing a bonding wire from the stator plate to the stator..) Where is your keyway in the pic though - at 6 o'clock, or thereabouts? If so, at that position it looks like the high point of the breaker cam is off to the left through to 11 o'clock (approx.). Without knowing and as I've not touched the cam during the stator cleaning session, is it possible to fit the breaker cam upside down on these?

Like your idea re. the conversion - obviously need this running properly though.

Take out the flywheel woodruff key, and persuade the cam off. I don't remember if these have a 2nd key for the cam, some do, but make sure its there or the cam is engaged into the flywheel key. It should be obvious when you get it apart which set up this has. The OMC cams say UP on the top, which makes putting them in a piece O pie. Generally the marked side goes up.

You can eye ball if the timing is in the right range, ie all the parts are correct and accounted for. Feel for TDC through the spark plug hole on the top (1) cylinder. Open the throttle fully. Unless the linkage is really wacked out the breaker plate should be about 32 degrees BTDC. Now turn the crank till the points for #1 open (Ohm meter). That point on the flywheel should be round about the 32 timing mark. Read the timing procedure backwards and you will see what I am doing.

I went out to the shop (brrrr) and took the flywheel off the 45 and took some better pics

This is with the #1 piston roughly (+-2 deg?) on TDC. And the throttle closed. Note the relative position of the key and the rubbing block of the points.

Now the throttle is wide open (WOT).

View of the other side at WOT.

Back at idle.

The funky shaped key has a tail that catches the cam. Lift the key up and wiggle it out of the cam. Don't try to drag the cam over it.

The cam has a PN# and an arrow, which goes UP. Check your PN in one of the online parts look ups to make sure its right.

I am 100% certain no one has opened this flywheel since 1974. All the paint was intact.

The missing bonding wire is a tell, I suspect. Magneto motors did not need them. Maybe parts mixing has gone on. But we will sort it out.

Thanks for this - I appreciate the serious effort. It's been raining non stop here since last weekend. The 55 is outside, with l/u buried in a drum I use to run them in - we had a serious frost, not enough to freeze the water though. Nights drawing in too - I hope to get to it this weekend which will be 'balmy' according to the weather guys. The key's been out before, it's like yours, one piece, but I'll make the effort to remove the breaker cam and get right back to basics on it. It's highly possible parts mixing has gone on, as the rectifier's home-made too - is possible the original failed, but there seem to be a lot of coincidences.

I will get photos of both sides and the ends so you can have a reference. This one had a terminal broke off the rectifier, but I fixed it with, carving, soldering, and JB weld.

Its laying flat, clamped to a 'H' shaped piece I use to move large motors flat in my trailer. I don't have a free stand strong enough I would trust it with this 140-50 pounder. So the picture background might look a little weird.

Well, sunny and bright today - the good news is the breaker cam was reversed. Turned it over - direction arrow and part number staring me in the face. Five mins of setting up the points again, on the point of the arrow, flywheel on, some choke and it started 1st time and soon settled into a decent idle.

Next job is to get the thermostat housing off (have replaced the impeller already) - one bolt is already sheared by the monkey wrench team and the other two are rusty - I reckon the thermostat is likely crusty and inoperable after so long. I will get the torch / heat gun out and go softly-softly on them. Lastly, I have a spare recifier and stator which I'll replace and make sure it's all charging fine + replace the bonding wire. Electrics are not my forte, so more bedtime reading with the manual..

Just shows you,I guess. The previous owner must have given up in frustration and left it in the shed for 20 years. l98tpi, I must thank you for persevering with all the pics and instructions though, very much appreciated.

Ah ha!!! I thought I didn't see any markings on the cam, and should have.

To get small bolts moving, along with something like PB Blaster. I like to put one needle of my needle scaler on small bolts and vibrate them. Not hammer so much that it peens. Turn the pressure down. I have had a good rate of success with this vibration technique. On larger bolts you can rattle with an air hammer, with a blunt tool in it.

After spraying and buzzing it off and on over hours and days. Break out the left hand drills and the Speedouts.

I have found a 1/4 hex drive impact driver will get out a lot of stuck screws without breaking them of spinning out the heads. I have got to the point where I always use the impact the first time I take a screw out.

Electronics are my forte, so ask away.

Mark

Thanks for the advice Mark. Looking forward to the rest of the work needed. It may be awhile, as I've got a slot at the boatyard to fix the boat. 10 years after restoration and some hard offshore use, I've got leaks, a cracked floor and some water saturation of the foam I put in originally, so has got to be done. I see you have a 650SS; our original boat was fitted with one - great motors.

Nick

Tada!

1967 Mercury 650SS the foot is in the slot in the stand leg. Its a good runner. Except I have nothing to run it on right now.

Good call on that cam. One of those things that can drive you bonkers.
Nice looking 650 there also.

Chirmobo, You are right about the Chryslers being simple and easy to work on. I have had very good luck with them too. That being said, I am looking for a 4 cylinder 80 hp Merc to replace my 55 hp Chrysler. If I fall into one o k , if not the Chrysler runs super good and a prop change will get me into the upper 20's with the old aluminum boat and I can live with that.

Sweet looking 650..The closest I have to that is a sad looking '76 850XS. One day I'll get to it.

Chryslers though - my folks had a West Bend 45hp which I thought was a smart looking motor, with it's swooping cowling and neat cable setup through the front tray. They didn't like it much, so I was scathing about them, until doing up my magneto 45hp and now working on the 55hp. Before this I did look at a 50hp '65 West Bend, pre-Chrysler, but it was tatty and expensive. I have a Duratech 13R copy that is the engine test bed.

You need one of these for the Chrysler 45 so it will be OEM and period correct.

It should work on the 55 also.
Guessed what it is yet?

I've been keeping an eye out on that auction site. Does it fit that way up? Would need to modify it for Teleflex, as my newly restored cable system ran through the inside of the gunnel (a 2in enclosed tube of ali) & was very stiff - the sides of the boat are not parallel and there was no intermediate sheave. Then, one day I was happily boating upriver when it all went slack - I was left steering a 40hp SkiTwin with a vice grip & poking the throttle with a boat hook from the back seat to get home.

That is a steering bracket for cable pulley, aka. pull pull, steering. There are 3 holes in the steering horn or extension in the front cowl pan. This goes up into the outer two with the loop forward. The toggles flip down and lock it in. After you thread on the two steering pulleys that is. Makes a neat, safe, and period correct job of it, just like mama Chrysler intended. about 15-20 bucks on fleaBay.

For that new fangled push-pull cable, just screw a ball stud or bolt/spacer for a heim joint, whichever setup it is, into the center hole. But those silly things will never catch on.

So you had cable pulley (i.e. sheave) steering that was stiff because the cables drug in the conduit? I have not tried this, but in a bench boating session I was told this. One of the guys had the same issue on a old bass boat (must have been the last one rigged with pulley cable), he slipped PEX tube (plumbing) through the conduit and ran the plastic coated cable through that. Thinking that poly plastic of the PEX would make things slick. Well it did work a treat, but not in the way he expected. The PEX slid more in the conduit than the cable in the PEX. But whatever, it was a cheap and easy fix (plumber leftovers) that left the boat looking original. I am really tempted to do this to my Larson rebuild instead of guide pulleys under the combing.

Well, I treated myself to one - I think is NOS, as it has no wear. Is slightly different from yours though, with that single bar and split pin.

Interesting fix re the steering; it'd probably work well too - I'd have to take off the end caps at the transom to slot the PEX tube in, as it's a square enclosed tube running the whole length of the boat - then I'd need to find some way of replacing what must have been a plastic bush in the tube that runs through the wheel, as it rattled as well. See how the wheel is angled acutely. It pre-tensions the cable, as it's below the sheaves mounted in the rail. I really think the system was an afterthought - until now I'd never seen a cast ali wheel like that either (is a copy of the Ford Anglia steering wheel). My 60s version of that boat was easier to set up with cable, but the teleflex is easier to live with on this one. My other boat is setup with cable, so I don't mind either.