johnson mainshaft woodruff key 1983 15hp

[apark999]

after my 1983 johnson 15hp made a loud rattling sound i removed the flywheel to find the woodruff key (the bit that sticks out on the shaft to mate with the flywheel) had been sheared off halfway. this means the flywheel is in danger of slipping off. ive tried to see if the key is removeable but cant tell, anyone tell me if this is the case or do i need a replacement shaft? would a weld hold the flywheel? any help appreciated thanks<br /><br />Alex

 

[wilde1j]

Re: johnson mainshaft woodruff key 1983 15hp

Don't weld. The flywheel needs to be pulled, the key remains removed. The flywheel/shaft may need to be lapped, the key replaced, and the flywheel nut torqued to the proper value. If you're not experienced, take it to a pro who is.

 

[apark999]

Re: johnson mainshaft woodruff key 1983 15hp

thanks for that, can u explain what u mean by "lapped"

 

[javsam]

Re: johnson mainshaft woodruff key 1983 15hp

the key does not keep the flywheel seated to the crankshaft. only the fit of the taper shaft between the flywheel and the crankshaft.this taper gives you the holding power of the fit.sometimes when a flywheel key shears it leaves metal embeded in the crankshaft taper.A paste of valve grinding compound spread on the crankshaft taper is the worked back and forth(this is lapping) using the flywheel. the object is to clean off any embeded particles on the crankshaft taper and flywheel. the two surfaces are then cleaned up of any compound and then installed with a woodruff key. then the flywheel nut is then torqued to the proper ft/lbs.It is highly important to torque the flywheel nut to the proper ft/lbs or the woodruff key will shear again.<br />javsam

 

[wilde1j]

Re: johnson mainshaft woodruff key 1983 15hp

What he said and make sure tapers are dry and perfectly clean when re-installing flywheel.