sheared woodruff key?

[Tim T.]

My question is this , will a 1987 50 hp Johnson run with a sheared woodruff key? My outboard runs but backfires through to exhaust just a little. I have rebuilt the carbs, replaced both coils and power pack, new plugs. before I remove the flywheel to see if it is the problem I figured I would ask the pros. Compression is 130 in both cylinders {harbor freight gauge}

 

[racerone]

The key controls the timing.-----Pull the flywheel and inspect.----Why did you replace powerpack and coils.

 

[Tim T.]

Thanks for quick response, well I used a spark checker and the top coil did not jump 7\16 inch gap and the coil did not look healthy[ a little melted on the bottom] so I thought that was it. So I thought the other coil can not be far behind, so I replaced both at the same time. But the top coil still would not jump 7\16 inch . So the next thing was the power pack and bingo ! it jumped 7\16 inch. can you tell me if it will run with a sheared key?

 

[racerone]

I clearly indicated that the key controls the timing.----It might run if flywheel is just slightly out of position.----And no you cannot find the sheared key with a timing light either.

 

[Tim T.]

Thank you for answering my question , I just did not want yo pull the flywheel if I did not have to.

 

[Chris1956]

If you find the key is sheared, you will need to get the broken part out of the crankshaft, and replace it with an OEM key. Normally it takes a small chistle or punch to get it out.

Usually the keys shear when the flywheel is not torqued properly, so get the factory torque setting and tighten it to spec.

Not repairing the key can lead to engine destroying actions.

 

[oldboat1]

could be a slight blockage in the low speed jet (top of carb) or h.s jet on the carb bottom. You might try spraying some carb cleaner through both.