Flywheel nut over-torqued on a 72 100hp rude??

dohdaman

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Aug 5, 2006
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Would a over-torqued flywheel nut put extra strain on the starter to where it would overheat?? The flywheel nut loosened while on the water, luckily made it back without major problem. Later discovered the woodruff key had sheared off. Replaced it and torqued the nut to the rated 100 ft-lbs per the manual. Now after trying to start it, the starter gear stops rotating after a minute or so of repeated tries to start the motor, though the starter shaft still rotates. After letting it sit to cool, it will work, but repeats the same problem. Im wondering if the flywheel is to tight and overheating the starter.
 

Silvertip

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Re: Flywheel nut over-torqued on a 72 100hp rude??

I doubt that's the problem. I'd be more concerned about the fact that the starter needs to spin for more than a minute to start the engine. Running it that long is bound to heat up the starter. Clean the spiral grooves in the starter shaft that drives the bendix upward. Make sure you have a good battery and that the cables are clean and tight (both ends). Fix the engine so the starter doesn't have to work so hard. You might post what your starting procedure is. There should be no reason you need to run the starter more than 5 or 10 seconds to fire an engine.
 

dohdaman

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Re: Flywheel nut over-torqued on a 72 100hp rude??

Silvertip said:
I doubt that's the problem. I'd be more concerned about the fact that the starter needs to spin for more than a minute to start the engine. Running it that long is bound to heat up the starter. Clean the spiral grooves in the starter shaft that drives the bendix upward. Make sure you have a good battery and that the cables are clean and tight (both ends). Fix the engine so the starter doesn't have to work so hard. You might post what your starting procedure is. There should be no reason you need to run the starter more than 5 or 10 seconds to fire an engine.
 

Joe Reeves

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Re: Flywheel nut over-torqued on a 72 100hp rude??

Shearing the flywheel key necessitates cleaning up thr tapers of the crankshaft and flywheel. INstall the new key with the straight edge being vertical with the engine, not aligned with the taper.

The flywheel nut torque is 105 foot pounds, not 100.
 

dohdaman

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Re: Flywheel nut over-torqued on a 72 100hp rude??

Starting procedure is choke it, turn over till she starts, then choke off. Does not start easy when shes cold, no problem after warmed up. The starter never did this before the flywheel came loose, but one problem can lead to another i guess.
 

dohdaman

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Re: Flywheel nut over-torqued on a 72 100hp rude??

I did clean both tapers with fine emery cloth, luckily it was in good shape. I initially put the key in following the taper, but noticed while sliding the flywheel down the shaft that the key shifted to a more vertical position, and seemed to hold fine. The Clymer manual shows 100 ft lb torque for a 100hp.
 

wilde1j

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Apr 15, 2002
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Re: Flywheel nut over-torqued on a 72 100hp rude??

That's why you should have an OEM shop manual.
 

imported_lorin

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Jun 23, 2006
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Re: Flywheel nut over-torqued on a 72 100hp rude??

Over-torquing the nut has nothing to do with starting it. Are you sure the choke is actually closing when you choke it? It sounds like it isnt closing.The only way to be sure it is closing is to look at it. You might have to remove the air box to see, of look at the choke lever whre it comes out of sthe side of the carbs.
 

dohdaman

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Re: Flywheel nut over-torqued on a 72 100hp rude??

My thinking on over-torquing the flywheel nut was putting increased resistance on the crankshaft, causing the starter to get hot
 

Pony

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Jun 27, 2004
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Re: Flywheel nut over-torqued on a 72 100hp rude??

I agree with the others, there is something else amiss besides and over-torqued flywheel nut. As others have said, if you torqued it to 100 ft lbs, than you are under-torqued.......

In your starting procedure you didnt mention whether or not you are priming the fuel system. You should be pumping the primer bulb until it is hard, then choking and trying to start the engine. If you dont, the fuel pump is having a REALLY hard time getting fuel into the carbs, then to the crankcase.
 

KYHunter2

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Mar 20, 2006
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Re: Flywheel nut over-torqued on a 72 100hp rude??

Your engine should start quickley.

In the winter it may be slightly slower to fire, but not much.

Its not like a vehicle, where the crankcase is full of thickened oil.

If your turning it over , for a minute or more.

Your starter will have a short life.

You need to find your starting problem and get it corrected .

As well as the torque on flywheel nut .

If its starting correctly, at least from my experience.

You won't even be able to hear the motor crank over.

Mine hits so fast, I allways think , I'm too slow letting off the key.

Once you get it to start correctly.

You need to remember the procedure you used , and duplicate it each time.

It varies from motor to motor slightly.

KYHunter
 

dohdaman

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Aug 5, 2006
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Re: Flywheel nut over-torqued on a 72 100hp rude??

I agree with the others, there is something else amiss besides and over-torqued flywheel nut. As others have said, if you torqued it to 100 ft lbs, than you are under-torqued.......
In your starting procedure you didnt mention whether or not you are priming the fuel system. You should be pumping the primer bulb until it is hard, then choking and trying to start the engine. If you dont, the fuel pump is having a REALLY hard time getting fuel into the carbs, then to the crankcase



I failed to mention that yes, I pumped the primer bulb prior to choking and starting the engine
 
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