1960 Evinrude 40hp Lark ll, help with the flywheel

[Grandpa Mike]

Well, we (my son and I) got the old beast resurrected. We started with an overhaul at the bottom end, new seals, and cleaning of the gear box. The bearings are good. No scratches, pitting and cages nice and tight. Buttoned it up with nice clean gear oil. Cleaned it all, resealed it and replaced the w/pump impeller and seals, o-rings etc...

We changed the plugs and thought we'd give it a whirl to see if it would fire. A bit of oil in the cylinders and some hand turning. After God knows how many years (or decades) it's been since it started.....(there were extinct species of spiders and other bugs under the cover)....unbelievably, it cranked for about 3 seconds, fired and ran.

It does start and run every time. After some bottom & top end carburetor adjustment, it smoothed-out as well as could be expected. We do have new points, coils, and plug wires which was our next step. At this point, I'd have to say that I was amazed it even cranked, much less started and ran. It does have a fairly pronounced miss throughout the RPM range. I'd add that the miss is intermittent and sounds like ignition or carb and not mechanical (like an ignition cross-fire). Looking at the plug wires, I'd guess they were factory, old, worn and cracked. My son told me looking at the coils (through the access hole in the flywheel)....he saw a cracked coil casing.

No biggie because we were going to replace all of that anyway.

Bottom line.....we cant get the flywheel off.

Even with the old illustrations we have and a combined 45 years of turning wrenches...we're stumped. We can't see anything hanging it up. It's a pretty straight forward set-up. Keyed on the end of a tapered crankshaft. We used a harmonic balancer puller and still managed to snap a few 1/4-20 bolts till we finally gave up.

My money say's the flywheel has never been off.

Any suggestions? Maybe something we missed? We sprayed some penetrating oil on the crank end and called it a day. We really put a helluva pull on it it and no-go. The ring-gear is still attached but I cant possibly see any interference from that. Before we get out the impact and some grade 8 bolts with the puller and go all Jurassic on the the flywheel, we thought we'd ask some fella's that have may have been there before. Thanks in advance guys!

 

[bonzoscott]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

Start with the grade 8 bolts. Not sure if those are what you broke. Get puller good and tight. Tap the top of center puller bolt few times, tighten some more, then repeat. Actually a bit more than "Tapping" the bolt but not serious whacks! Personally, I have always used an impact with very short bursts but some may advise against that method.

 

[lindy46]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

X2 to the impact wrench - pops it every time.

 

[kbait]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

Leave the flywheel nut loose and level w/top of crankshaft. When she pops, you won't have a flywheel living up to it's name!

Grade 8 bolts should do the trick.. grade 8 washers too.. and lift/pry up gently on the flywheel (just take up that little bit of play) before banging on the centerbolt of the puller.

Good luck!

 

[kfa4303]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

+1. Grade 8 bolts and washer, a good flywheel puller and some patience (or an impact wrench) should do the trick. As kbait said, leave the flywheel nut on so the flywheel itself doesn't go airborne. Don't be surprised if it makes a loud BANG when it comes free. Here are some handy pics and links.




Reviving a Vintage Big Twin - Part 1

 

[Grandpa Mike]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

Thanks to all and to kfa4303...Great Link!

Yup, I was thinking that it's just being stubborn but still wanted a bit of reassurance before I did something galactically stupid. I have all the confidence in the world when it comes to automotive applications but thought just maybe the "boat guys" know something I don't. It sure wouldn't be the first time.

The flywheel appears to be cast aluminum and the last thing I wanted to do was get too aggressive with it only to find out that there is some "coxswain's thru-bolt" or something else peculiar to marine outboards. Stranger things have happened.

As it is, it's marinating in penetrating oil waiting for the next boat repair weekend. An impact and some grade 8 bolts to use with the puller are next on our "to-do" list. I can't wait to get the new coils, point-sets and plug wires on it. Ought to make a heck of a difference. Thanks for the help guys!

 

[Grandpa Mike]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

My son just sent this picture. I guess under a good pull and enough penetrating oil, the flywheel finally gave up. Holy Cow I'm amazed it even started and ran in the first place. I'm gonna say our ignition miss was on account of the coil cases being cracked and roasted. Comments?

I cant wait till our next "fix the motor" weekend. I bet new coils, point-sets and plug wires are gonna make a heck of a difference! Whew!



I'd say these are original coils and points. I doubt the flywheel has ever been off and the plug wires are definitely factory!

 

[kodibass]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

It would be fun to know the history of these original omc coils, Like who came up with the recipe for the coating & such..& what it actually is..how long the made them out of this material & was this coating used for other applications etc. Good thing Evinrude never built a plane!

 

[gm280]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

My son just sent this picture. I guess under a good pull and enough penetrating oil, the flywheel finally gave up. Holy Cow I'm amazed it even started and ran in the first place. I'm gonna say our ignition miss was on account of the coil cases being cracked and roasted. Comments?

I cant wait till our next "fix the motor" weekend. I bet new coils, point-sets and plug wires are gonna make a heck of a difference! Whew!

View attachment 186896

I'd say these are original coils and points. I doubt the flywheel has ever been off and the plug wires are definitely factory!

You didn't specify but I'm sure you will also change the condensers while in there refurbishing the points and coils. Yes they do get to looking pretty dire some times. But it is amazing how they will come back to life real quickly with just a few new parts and some cleaning... I was going to concur with the three grade 8 bolts and the impact wrench as well. I had to do that myself after breaking two sets of grade whatever type bolts... Once I bought the grade 8 and hit it with the impact wrench, it came apart with that loud cracking sound...but all was okay, nothing actually cracked...

Keep us informed and updated...

 

[HighTrim]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

When you get into the very old coils, the ones before the 50s, they were made with a petroleum based tar potting and most are still going strong. It was that plastic potting they toyed with in the 50s that failed. I dont know what type of platic/additives they used, but obviously they are not using that formula anymore. I guess our grand kids will find out how well the new style potting material holds up.

 

[HighTrim]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

I would also like to advise against using an impact wrench. I admit, I have done it in a frustrated attempt to get a post 1960 flywheel off a Big Twin with the larger crank. The law of nature states that something has to give though. IF the only thing holding the flywheel on is the pressed torque on the taper, it will usually be ok. However, if there is something else going on there, you could really cause much more headache than simply a stuck flywheel. I am actually working on one of my most stubborn ever. Been 3 days now of heating with a torch, oiling, tightening the puller, heating, freezing, tightening, etc.....

I would suggest an extension on the breaker bar of the puller instead of an impact wrench. It gives you more control, and less chance of catastrophic damage. If it doesnt come off with 2 men, 1 holding the flywheel hlder, 1 puller on a 3' extension, using grade 8 bolts buried 1/2" into the flywheel, there is something wrong. As stated as well, ensure you pry UP on the flywheel before hitting the puller bolt with a hammer or you will get internal damage that is much worse than the stuck flywheel. Keep the huge sledge hammers on the shelf, a smaller hammer is all you need.

That all said, hopefully I can use my own advice and get mine off this weekend, its killing me. Previous owner may have used loctite on the taper or something. Silly rabbits.

 

[gm280]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

When you get into the very old coils, the ones before the 50s, they were made with a petroleum based tar potting and most are still going strong. It was that plastic potting they toyed with in the 50s that failed. I dont know what type of platic/additives they used, but obviously they are not using that formula anymore. I guess our grand kids will find out how well the new style potting material holds up.

HighTrim, not sure how old you are, but back in the 50's and 60's all types of plastics were deemed "forever" type products. I remember them saying that once plastic was made it lasted forever and would not decompose...yes right! They even talked about how it would stay in the landfills and never break down and decompose... Now we see that most all plastics will crumble in UV light and quickly too. So they probably thought making the coils covered with plastic was a forever part. But you are correct about our grandkids actually seeing how good products built these days will last...

 

[Grandpa Mike]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

You didn't specify but I'm sure you will also change the condensers while in there refurbishing the points and coils.

Absolutely, not changing the condensers (capacitors) while not critical...would be like tuning-up a V-8 with 7 spark plugs. As a matter of fact, the actual capacitance value, usually .22uf in breaker point application... can be checked and "tweaked".

Not a lot of folks pay attention to this but a careful inspection of the breaker point contact surfaces will indicate how well your system is working. Breaker points should wear evenly, pitting occurring equally on both the ground half of the point set as well the half on the moving arm.

If it isn't, then your condenser is not at the correct value. Measured in uF, or micro-farads it absorbs the voltage spike that occurs when the magnetic field in the primary coil winding collapses.

 

[HighTrim]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

Well it could be critical if they are right shot.

Any from 0.16 to 0.24 UF should be fine for your motor. Capacitors with appropriate rating can be used in lieu of the original, only pennies at your local radio shack. Just twist one lead under the mounting screw to ground, the other to the points screw.

 

[Grandpa Mike]

Re: 1960 Evinrude 40hp Lark ll, help with the flywheel

I bought point's, condenser's and coils here at iBoats. I don't think I'll lay awake at night wondering if they are the correct capacitance. For that matter, a wire stuck into an orange would do a better job than the 50 y/old ones. Don't laugh, an orange will get you home in an automotive application.

 

[PlankingThing]

New Here - so Here Goes !

New Here - so Here Goes !

Leave the flywheel nut loose and level w/top of crankshaft. When she pops, you won't have a flywheel living up to it's name!

Grade 8 bolts should do the trick.. grade 8 washers too.. and lift/pry up gently on the flywheel (just take up that little bit of play) before banging on the center-bolt of the puller.

Good luck!

Hi, Guys have been hiding out reading when I have time , I have an Old 15 hp outboard Chrysler
It did Me the same way , and I checked everywhere as I was Freaking out _ It sure Felt like I was going
to break that - Alu. Flywheel .

I didn't get good answers ( Even thou ) I did get some Answers from searching the internet , Nothing was Complete !
It was always 3 Feed Backs or 15 Feed backs and the Final Results were Not there . It seems a lot of Folks just get a result or Figure it out on their own at some input , but Never Update the Site or Other
as to the : ( FINAL Resolution ) .

I have done a few custom Scoots ( Built ) and a few Car Mods in My Day .
Porting and Snowmobile Porting & Racing .

This is what Happened to My 15 Hp Motor , Yes 2 Guys , and a breaker Bar on the Puller , slowly Tightening
the Puller ( Adding Pressure ) - Did the Heat _ Big Time and Cooled the Crank End with Spray - Rust Easy !
I Bet I had at least 90ft. lbs -110ft. lbs. on the Puller after 3 attempts ( Building as We went ) .
Crank Nut as Described above with a Washer centered over the Nut - which the Puller Quickly Shaped Into a
small V - Funnel . Got right to this point of - No Return _ that's when We broke out a Nice pc. of
Oak and a 2 lb Hammer , while the other Guy Held & Lifted Up - I gave Her a few good Pops .
2-3 Quick Sharp Pops : Slid Right Up . :joyous:

Nice Site - Guys : I just bought up a 40HP Evinrude :
I'll be needing Help with this One _ Once I Dig into It .

Thanks
Dan

ps: Before some Guy say ( Wood ! ) ?
Here's the Deal _ Wood has a Low Drumming Shock Wave - It sends into the Metal !