Is nine months long enough?

[adsm08 4,864]

@PWL216 That's kind of a crap angle on the first picture.

 

The key doesn't look sheared to me, but it sure does look beat up, and I see a few other things on the crank that make me think that flywheel was spinning on it.

[Bill D 3,031]

27 minutes ago, adsm08 said:

@PWL216 That's kind of a crap angle on the first picture.

 

The key doesn't look sheared to me, but it sure does look beat up, and I see a few other things on the crank that make me think that flywheel was spinning on it.

Agreed.   Part of the key is supposed hold the trigger wheel in time.  Pull the key and post a picture please.  Pretty sure it's sheared.  If you look at the picture of the crank trigger wheel the notch for the key is at the top, not in line with the keyway.   I think we found the problem.  You'll need a new key and maybe a new crank trigger wheel.  Key is PN 515-0284

Edited 17 hours ago by Bill D

[PWL216 1,248]

Requested pics.

[PWL216 1,248]

29 minutes ago, adsm08 said:

@PWL216 That's kind of a crap angle on the first picture.

 

The key doesn't look sheared to me, but it sure does look beat up, and I see a few other things on the crank that make me think that flywheel was spinning on it.

Agreed. The crank is gouged pretty well

[Bill D 3,031]

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.ebay.com/itm/187139873092&ved=2ahUKEwiqyKOBraaWAxVhq4kEHSRvD7AQqa4BegQIThAA&usg=AOvVaw29kSzXkoLyxbxLVKcjEsmh

 

Definitely the wrong key.   This is the key you need.  An OEM Onan key is cheaper from the Cummins website.

Edited 15 hours ago by Bill D

[lynnmor 8,950]

Here is the key you need:

 

 

[PWL216 1,248]

Thx guys!! updates to follow…

[sqrlgtr 3,506]

Some great info in this thread and can't wait to hear about that big smile when @PWL216 gets it running again. I really like that P220 hum. If it hasnt been mentioned already would definitely decarb, check 2 piece manifold, clean carb and adjust/inspect valves why you have tore down this far.

[Bill D 3,031]

That crank is pretty beat!! @lynnmor what do you think.  Is it salvageable?

 

[sqrlgtr 3,506]

5 minutes ago, Bill D said:

That crank is pretty beat!! @lynnmor what do you think.  Is it salvageable?

 

you guys are a lot more knowledgeable than I am but I sure would clean it up good and try it. just my  though.

[PWL216 1,248]

11 minutes ago, sqrlgtr said:

you guys are a lot more knowledgeable than I am but I sure would clean it up good and try it. just my  though.

That’s the plan, I hope. 

[wallfish 20,338]

That flywheel had definitely spun before and probably because someone put a little woodruff key in there. I don't see that as being the end of that shaft though. Just put the proper key in it and it will hold.

I'm no Onan expert and barely know them but most every other engine uses a taper fit lock instead of relying solely on a key to hold them in place for a reason. That's a straight shaft fit so the long key is definitely required 

[Bill D 3,031]

9 hours ago, wallfish said:

That flywheel had definitely spun before and probably because someone put a little woodruff key in there. I don't see that as being the end of that shaft though. Just put the proper key in it and it will hold.

I'm no Onan expert and barely know them but most every other engine uses a taper fit lock instead of relying solely on a key to hold them in place for a reason. That's a straight shaft fit so the long key is definitely required 

Someone probably replaced the ignition module but never properly torqued the flywheel bolt when they put it back together, which made the key shear.  The long key is used to hold the trigger ring in time.  Someone else on here had the same problem with a sheared flywheel key due to the PO not torquing the flywheel bolt properly.  Does the flywheel bolt have the correct thick washer with it?

Edited 5 hours ago by Bill D

[953 nut 67,883]

9 hours ago, wallfish said:

That flywheel had definitely spun before and probably because someone put a little woodruff key in there. I don't see that as being the end of that shaft though. Just put the proper key in it and it will hold.

I'm no Onan expert and barely know them but most every other engine uses a taper fit lock instead of relying solely on a key to hold them in place for a reason. That's a straight shaft fit so the long key is definitely required 

Since the flywheel has obviously been spun on the crankshaft you should also take a good look inside the flywheel bore.     

[c-series don 12,232]

Maybe it’s just the angle of the picture but it appears that the key way in the flywheel is worn? A thorough cleaning will help determine that. 

[cafoose 3,785]

Looks like part of the long key is still on the crankshaft.

[lynnmor 8,950]

2 hours ago, c-series don said:

Maybe it’s just the angle of the picture but it appears that the key way in the flywheel is worn? A thorough cleaning will help determine that. 

 

I'm having a problem with the photo angle as well.  The crankshaft should be tapered and the tail of the key rides above and locates the magnet ring to time the ignition.  That magnet ring may be damaged with the failure.  It appears that the crank has grooves worn in it and that may not grab the flywheel well.  Any debris and high spots on the crank and in the flywheel needs to be removed and then the parts can be lapped together with fine lapping compound.  The surfaces need to be completely clean and then only a wipe of rust proofing applied.  The flywheel bolt torque is 55 ft. lbs. with a drop of oil on the threads and under the bolt head.  What really is needed is replacement of the crankshaft and flywheel, using these parts might very well cause a failure in the future.

[squonk 47,550]

At very least clean up the shaft and flywheel bore and apply Loctite bearing and sleeve retainer. give it a shot. You can't spoil a rotten egg!

Edited 1 hour ago by squonk