Flywheel removal

[putback]

I'm going through a running 1962 evinrude speeditwin 28 hp. I need eyes on the ignition components. The problem is removing the flywheel. I've searched the forum and found a lot of info, some I don't dare try. I've never had a flywheel on any engine this stuck. My 1st question is how much stress can I apply with a proper puller before I ruin the wheel. I've taken it to 70 ft lbs with the torque wrench. Being aluminum I concerned with pulling out the threads on those 3 little 1/4" bolts, they're only anchored in about 1/2 inch of alum. After the 70 lb pull those bolts feel tight when I removed them. I've hammer tapped the puller bolt firmly, question is how much of a hit can the crank take? I read heat, I've used it often on other things but this is aluminum with a steel insert. To heat that steel collar on the crank enough to expand what damage will I do? I read take the puller down with an impact wrench, I ain't got the guts to try that on this little engine! Sum it up in 2 questions. Any other ways? If not how much pressure can the flywheel take before I break it?

 

[nwcove]

if the puller bolts are all the way into the holes, you would be surprised on how much stress the flywheel will take. any bolts less than grade 8 will stretch or break. tighten the puller down as much as you dare, then lift up on it and whack it with authority. if that gets you no where, spray it with a good penetrant and wait. be sure to keep the fw nut on a few threads tho, when it lets go it could be violent. patience is the key for a stubborn one . ( it could pop off in the middle of the night )

 

[F_R]

Those bolts go into the flange of the steel hub cast within the flywheel, not into aluminum. Use hardened (Grade-8) bolts, screwed in 7/16", no more and no less, and tighten that sucker as hard as you can. If the puller breaks, get a better puller. If it still won't pop off, lift up on the rim of the flywheel and give the center puller bolt a sharp rap with a hammer. And put away that sledge. It is the shock that does the trick, not the bash. Personally, I use a 12oz hammer, and have removed way too many of those flywheels to count. If you are not bashing it, the question about how much it can take becomes moot. Yes, they are tough to get off, but you don't have to go to extremes.

 

[achris]

Best puller I ever made was a strip of 3/4" steel, with the flywheel bolt holes drilled in at the right spacing, The centre hole is threaded fine (9/16" if I remember correctly), and a hardened forcing screw threaded through. The end of the forcing screw is rebated for a small ball bearing to sit in... NOTHING has resisted it for long

 

[racerone]

As stated the hub is steel.----------The 1/4-20 bolts are big enuff for this job.-----OMC would have changed to bigger bolts if it was a problem !!!

 

[gm280]

You are going though the same issues so many others (self included) come on here asking about. Some of those flywheels feel like they are welded to the crank. But believe us, it will let go and when it does, it will probably scare you with the sound as well. I personally popped two sets of 1/4 X 20 bolts before I went and bought the grade 8 bolts. Anything less then grade 8 is probably not going to do the job. And like you, I thought I was going to break the flywheel by applying so much force. But it did come off and all is well in the universe again...

 

[putback]

1st and foremost thanks to all above. You were right. With your combined reassurance I put the pressure on the puller. The flywheel popped right off w/o the hammer. No damage. I've pulled a lot of things in my years but to scale I'd say this little sweetheart withstood the most stress. In hindsight all for not. Every ignition component was brand new, coils and all. For those that find this through "search" in the future. Follow the above advice with confidence, its 100% spot on. One little gem of advice someone may overlook, the 7/16 depth. Had F_R not posted that I would have gone deeper to insure I had max grip and probably ruined the coils. You wouldn't know that until you have the flywheel off, then its to late.

 

[gm280]

Bravo, Bravo, glad to hear success... :thumb: :thumb:

Now you too can explain to others asking the same questions about removing their flywheel. It just doesn't seem like a tapered shaft can hold that tight. And that brings up another point. Make absolutely positively sure that both the flywheel AND the crank shaft tapers are both totally 100% clean with NO lubricant or anything on them what so ever when reassembling it again...Very important! Nothing but clean metal...period!

 

[F_R]

And you MUST use a torque wrench to tighten the nut to 100-105 ft/lbs. Don't dare think you can guess at it. You would be surprised how many crankshafts and flywheels are destroyed that way. Don't have a torque wrench?? Places like Auto Zone have loaners.

 

[putback]

Yep, learned that one the hard way at about 14yrs old. Redid a Wisconsin baler engine, strapped it to a doddle bug, flywheel broke free in motion. Shrapnel everywhere including my leg. After my old man and his buddies chewed me out and calmed down dad gave me my own torque wrench. Still use it to this day w/o exception. God bless those old timers, they sure could "learn you a lesson boy". Did'nt stop us from doing what boys did, they taught us to do it right.

 

[achris]

Don't forget the woodruff key too....