Need a Yamaha part - that isn't available... flywheel woodruff key

tod osier

tod osier

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I'm in the process of changing my flywheel on my Yamaha F40 for a toothed flywheel so I can add electric start. I pulled the flywheel and the woodruff key on the crankshaft is sheared (and the flywheel rotated a bit, but not much, obviously not too much as the motor was running well). The keys are out of stock and are backordered everywhere and expected Sept 30 at Yamaha USA.

I checked with all the big places I know of Boats.net, Crowley and Sim along with every other place I could find that listed the part number. Other superstores out there or places to look?

Were it a regular piece of equipment I'd just measure and get a new one from anywhere, what are people's thought on that? It had sheared once, so id want the best part possible. It is in 2 pieces so tougher to get a good measurement if I went that route.

Thoughts?!?!?
 
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Woodruff keys are usually standard items. Did you try NAPA? McMaster Carr online is a good source.

https://www.mcmaster.com/woodruff/

Rick
 
Richard Lathrop said:
Woodruff keys are usually standard items. Did you try NAPA? McMaster Carr online is a good source.

https://www.mcmaster.com/woodruff/

Rick
Click to expand...

Thanks! I had that thought off the bat and couldn't find a metric key that measured out even close (assuming it would be metric), BUT I just looked again and it measures out about as close as I can measure with dial calipers matching a #61 (3/16 x 5/8) key.

Does anyone know if a flywheel key would have any special properties? or would a standard one do? It does seem pretty soft steel.
 
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tod osier said:
Were it a regular piece of equipment I'd just measure and get a new one from anywhere, what are people's thought on that? It had sheared once, so id want the best part possible. It is in 2 pieces so tougher to get a good measurement if I went that route.

Thoughts?!?!?
Click to expand...

Tod,
Good info in 1st response.

Best to measure the shaft to determine the required key size. Width of the slot (thickness of key) should be straight forward. Measuring the radius cam be accomplished with a set of radius gages.

In leu of a gage, just buy a couple extra woodruff keys. It should be apparent which size fully seats into the cut on the shaft. The key fill either not fill the slot towards the ends (key too small of a radius) The key will stand too tall/proud of the shaft (more than the depth of the keyway in the flywheel).
Or it will be just right. [cool]

You can even do this with a set of woodruff keys in a thinner thickness (just to be used as gages) making them easy to insert and remove. Once the proper radius is determined, you will all set to install the correct key with the right thickness as well as the correct radius.

I'd suggest a stainless key just because it will be softer than a carbon steel. I can't say for sure what material the OEM key would be. You might ask your local dealer.

Many direct drive lawn mower engines use a pot metal/aluminum key precisely so the key will shear if the blade hits something. You must have pulled really hard to shear the old key. [;)]

PS, also note the high-profile keys listed that have the extended feet. Not absolutely needed but that style is often used on a tapered shaft. If the upper portion of the sheared key does not seem to match up to the lower portion, this may be the reason.
 
tod osier said:
Richard Lathrop said:
Woodruff keys are usually standard items. Did you try NAPA? McMaster Carr online is a good source.

https://www.mcmaster.com/woodruff/

Rick
Click to expand...

Thanks! I had that thought off the bat and couldn't find a metric key that measured out even close (assuming it would be metric), BUT I just looked again and it measures out about as close as I can measure with dial calipers matching a #61 (3/16 x 5/8) key.

Does anyone know if a flywheel key would have any special properties? or would a standard one do? It does seem pretty soft steel.
Click to expand...

Now that you have a size, check with a hardware store or a lawnmower repair shop for a pot metal/ aluminum key. If you think that would be a better match to the OEM.

There really is very little "load" on the flywheel. When subjected to a sudden stop, better to shear the key than bend the crank.
 
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Thanks Dave, i hadn?t thought about the potential of a shear key. I think I?ll try to find stainless given the amount of saltwater use.

Getting into the flywheel and getting the flywheel pulled is about a 10 minute job, so if I don?t like what I have and want to replace the key I can.

I have a nice batch of parts streaming in, so i have plenty to keep me busy.... new timing belt, thermostat, impeller kit and seals, etc...
 
Todd, Try Chatlee Marine. They are in Sanford N.C. Pretty big marine dealer. If they have it, should be cheap to ship. Then you will have one to
match too. 919-774-1203
 
Sonny Williams said:
Todd, Try Chatlee Marine. They are in Sanford N.C. Pretty big marine dealer. If they have it, should be cheap to ship. Then you will have one to
match too. 919-774-1203
Click to expand...

I?ll call today after they open up, thanks.
 
Made good progress, got a #61 key from Tractor supply that was a perfect fit and got the flywheel on. I have all the parts on hand except wiring to wrap this project up. Starter is in and it works when jumped from the battery. I am just waiting on wire and lugs to get it all together. Will be nice after all these years of pull starting that big sucker to have electric start.
 
Congrats. That's one of those projects so many people ask about but seldom follow through and make it all work. Now you've got me wondering about my 25 hp Yamaha. I mean I already have a battery in the boat a couple feet away...

Eric
 
Eric Patterson said:
Congrats. That's one of those projects so many people ask about but seldom follow through and make it all work. Now you've got me wondering about my 25 hp Yamaha. I mean I already have a battery in the boat a couple feet away...

Eric
Click to expand...

I'm a little surprised how expensive it ended up being, but I saved a lot buying used or aftermarket. I bought a mix of new and used parts that best satisfied my personal notion of value. I got a pristine flywheel for $80 off ebay (a $400+ dollar part new from Yamaha), I bought a new aftermarket starter (ARCO) for $150 ($300+ new from Yamaha), wiring and miscellaneous was up around $200. That is without updating for charging, which would have included a new stator and more.

Finding someone with a complete set of take off parts might be the way to go for some. I've seen a couple people listing parted out motors that matched mine since I bought the flywheel, but the problem is so many of the parts' wiring is integrated in the wiring harness, to tear off the harness and potentially troubleshoot any problems with a new used harness is more than I have in me. Adding just the starter as a peripheral was the right mix for me.

I bought the motor new 20 years ago and got it as a last years left over for a smoking great deal. It has been a super motor and the only issue is the manual start on super cold mornings. It is usually a one or two pull motor to start the day, but I've had 2 days in 20 years that I gave up and headed back home because I wasn't able to start it. One of the days I was on the water later in the morning after 5 minutes with a hair dryer. I'll probably have it die on my this year after all the work I put into it.
 
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I upgraded a 1995 Johnson 25 hp to electric a couple years ago. This is just a spare motor for me that I was planning to use with a new build of a BBIII.

I priced out new parts and it was not going to happen. Ended up finding the parts I needed thru a used parts dealer in northern Minnesota that I had previously purchased from for a lower unit. When I purchased the motor new, I right away added the stator and flywheel so I could run lights at night without need of a battery. So I still needed everything else. I got a real good price ( less than 300 dollars) for cables, switch, brackets, starter, solenoid, etc. That included shipping to my door and I had it the next day.

Still a spare motor for me but thinking of selling it. Doesn't look like I really need it and hate to see it just sitting in the garage.

Eric,
Make that upgrade, your arm is not getting any younger. [cool]

Tod,
Good you found a key. Seems like sometimes it just a 50 cent part holding a project from completion.
 
Huntindave McCann said:
I upgraded a 1995 Johnson 25 hp to electric a couple years ago.
Click to expand...

Thanks Dave, you are the one who inspired me to do it. I figgured if you could do it... :).
 
"Congrats. That's one of those projects so many people ask about but seldom follow through and make it all work. Now you've got me wondering about my 25 hp Yamaha. I mean I already have a battery in the boat a couple feet away..."


Yep, same exact thoughts here!
 
Got it all together today, took 6 hours to build the wiring harnesses and get it all installed and running.

I need to put a protective sleeve on the wires from the battery to motor, but I have it ordered and it shouldn't be a bad job. So basically done and got a bunch of routine maintenance items covered: new timing belt, new thermostat, adjusted intake and exhaust valves, swapped out my banged up prop for a shiny rebuilt one, got my tiller adjusted so I don't have limp tiller syndrome anymore... it stands proud now.

Making the harness with #4 AWG.

I invent jobs to use the hydraulic crimper, love using it.
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All the parts installed and wired.
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New button switch for starter (black one, kill switch is the red one).
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