Bent Flywheel or Crank?

[joe7670]

So after a few weeks of trying to remove the flywheel the right way, move on to another idea(which now I realize wasn't so great).

Propped flywheel with a 2X4 on each side running to the ground. Raised boat and basically rested weight of boat and motor and all on the flywheel. Then hit the puller on the top in escense pushing the crankt out of the flywheel.

Well, flywheel came off.

But when I put it back together and I try to spin the motor it has a hard spot each time it spins around. Enough to make the starter not be able to crank. Hard spot is in the same area each time and is apparent even when the plugs are out. Pistons are free, so it's not that.

Any ideas on best way to figure out if I bent the crank or the flywheel? It's not a question of if something was bent but more of what was bent.

 

[bktheking]

Re: Bent Flywheel or Crank?

Maybe bent the crank, usually I use a prybar and a air chisel, they come off in 5 seconds. Check your flywheel key to make sure everything went in straight.

 

[mikesea]

Re: Bent Flywheel or Crank?

most likely the flywheel,see if you can borrow one from a local shopor,gamble and buy on off ebay

 

[petryshyn]

Re: Bent Flywheel or Crank?

remove the flywheel, reinstall the nut and turn crank over, observing if it still binds and turns "true"

 

[joe7670]

Re: Bent Flywheel or Crank?

Sweet! Excellent idea. Will try that tonight.

Keeping my fingers crossed that it's the flywheel!

 

[wilde1j]

Re: Bent Flywheel or Crank?

Pull the spark plugs, set up a dial indicator against the crankshaft and have someone rotate the prop in gear to turn the crankshaft. You'll know immediately if the crank is bent.

 

[14ftgrumman]

Re: Bent Flywheel or Crank?

You don't tell us what engine you are working on. And why did you pull (or in this case-push) the flywheel?

If you were going to change coils, it's possible that you have a coil not in correctly and the flywheel is hitting it.

Dead on with the dial indicator on the crank, though.

Also, the flywheel could not be square on the shaft. Check for debris, and might as well get a new key and torque the flywheel nut on reassembly.

 

[joe7670]

Re: Bent Flywheel or Crank?

Well bad news, it's not the flywheel. Removed flywheel, pulled plugs, put motor in drive, and cannot spin the prop.

Put the nut on the crank and tried to spin with wrench and does the same thing as before. Goes around somewhat free to a certain spot on each turn.

As far as reason, I was pulling it to replace timer base. Lost spark and diagnosed it to the timer base.
I know I have spark now cause when I spin it without plugs using starter I was able to see it. So I fixed one problem but made the motor pretty much useless!

I'm guessing it's more worth it to sell for parts at this point considering it's got a new timer base, fuel pump, one new coil. Sitting on a 1967 17' wellcraft which is also not worth much but is still in working condition.

Some gas and a match will solve the problem!

 

[bktheking]

Re: Bent Flywheel or Crank?

Maybe you bent the shaft going from the powerhead to the waterpump, pull the lower unit off and try rotating the powerhead with the lower unit off. I don't think you have checked it out enough to start setting fire to your boat/motor, but man do I know the feeling! You would be able to tell if the top of the crank is bent visually, if it's still perfectly straight then the shaft to the water pump may be bent, that would be a first!

 

[Joe Reeves]

Re: Bent Flywheel or Crank?

And this engine is a Ford 302 V8?

It would help if you would tell us what engine we're speaking of.

Drop the lower unit, remove the spark plugs, then using a breaker bar/socket on the flywheel nut, turn the engine over. This will tell you if the problem is with the powerhead or the lower unit.

 

[joe7670]

Re: Bent Flywheel or Crank?

Shoot sorry, 1987 70HP Johnson.

 

[bktheking]

Re: Bent Flywheel or Crank?

And this engine is a Ford 302 V8?

It would help if you would tell us what engine we're speaking of.

Drop the lower unit, remove the spark plugs, then using a breaker bar/socket on the flywheel nut, turn the engine over. This will tell you if the problem is with the powerhead or the lower unit.

Exactly, pull the lower unit. It take a crap load of force to bend a steel crankshaft!

 

[bktheking]

Re: Bent Flywheel or Crank?

Question Joe, did the lower unit hit the ground when flywheel came off, you state that the boat was suspended in mid air by 2x4's? Are you sure the prop shaft isn't bent??? The crank and or flywheel sounds fine, this is lower unit stuff.

 

[joe7670]

Re: Bent Flywheel or Crank?

Lower unit didn't hit ground as the boat was in the air (off the trailer) only by like 2-3 inches. So when it gave, boat landed on trailer.

Interesting that it could be lower unit. Didn't consider that.

We did hit the puller with a small sledge hammer so maybe I jammed or broke something in the lower unit with the pressure being applied?

Worth a shot. Tomorrow will be questionable, but Wed. will drop lower unit to see.

 

[bktheking]

Re: Bent Flywheel or Crank?

I was just looking at exploded view of that crank, there is a roller bearing assembly at the top where you hit it with a sledge, may have damaged it. Pulling the lower will isolate powerhead. Let us know, this one is curious.

 

[joe7670]

Re: Bent Flywheel or Crank?

Guess anything is possible, but it gets tight at the same spot each time around, so I doubt it's the roller bearing. I would think that it would vary?

Definitly interesting but tiring.

 

[Faztbullet]

Re: Bent Flywheel or Crank?

It most likely one of the following: (1)The crank snout is either bent and binding against timer base internally or outer side of stator, (2) Upper roller bearing has can apart due to pounding and rollers are locking up between counterweight and front side of crank case.

 

[Sea18Horse]

Re: Bent Flywheel or Crank?

Were you yanging away on the puller with the sledge hammer before you rested the weight on the 2x4s also? If so this is most likely what caused the damage. If you do that without lifting up on the flywheel first then all that force is applied directly to the thrust bearing. Definitely something it was never designed to handle. This is why it's so important to lift up on the flywheel before smacking the puller mandrill with a hammer. When you pull up on the flywheel you can feel a certain amount of freeplay. You must lift the flywheel to the top of this play before you smack it with a hammer. Good luck with it anyway!

Cheers..................Todd

 

[joe7670]

Re: Bent Flywheel or Crank?

Without the 2X4 I didn't hit it with the sledge hammer. Did tap it with a smaller hammer and used a lot of impact gun with no luck.

 

[TheVicMan]

Joe - Did you ever figure it out? I just inherited my father-in-law's 1968 Evinrude 3hp, I had a heck of a time trying to get the flywheel off and gave my puller a few good cracks with a hammer trying to loosen it up but I finally got it off. I replaced coils, condensers and points. Put it all back together and I'm having the exact same results that you did. The flywheel catches at the same point in every revolution. Is it worth trying to fix? Did you ever get to the bottom of what was broke or bent? Would really like to know if it's something I can tackle.

Thanks,

Victor