JS63 Motor replacement

[marvelous29323]

I have a JS63 that I really liked and slightly hit a water meter and now it is knocking and shaking when restarted, the shaft does not look bent and when I take the blade off it does the same thing.

I am thinking of replacing the engine, would like to know if the process is difficult, any tips on the process I have located a new engine for $145 so I think it would be worth it because the rest of the mower is in good shape. I am fairly mechanically inclined but dont want to bite off more than I can chew.

 

[mechanic mark]

Service owners manual, first check oil level, what does oil on dipstick look like? any metal particles? if oil looks good check underside of deck, thorough inspection, inspect blade, bent or cracked? If everything looks good I would purchase new blade and give it a try.

If engine mount bolts to deck are tight, key under flywheel is not broken, blade adapter is not bent or cracked, you're crankshaft is bent. Take pictures or make drawing especially for cable or cables installation points at carburetor etc. Crankshafts are brittle material, hitting a water meter would most likely cause crankshaft damage. Let us know how it goes, thanks.

John Deere JS60 JS61 JS63 21" Walk Behind Mower Manual | eBay technical manual, should cover everything about your mower.

 

[marvelous29323]

Service owners manual, first check oil level, what does oil on dipstick look like? any metal particles? if oil looks good check underside of deck, thorough inspection, inspect blade, bent or cracked? If everything looks good I would purchase new blade and give it a try.

I will check the oil tomorrow, but I did try a new blade and it didnt change anything.

 

[redmondjp]

Replacing the motor is not that difficult but there are a few key areas to pay attention to in this order:

- Shaft diameter, length, and keyways (for blade adapter and for power drive pulley, or for the blade brake clutch if so equipped)

- Interference between any part of motor and discharge chute (which can sometimes be eliminated by rotating the motor to a different orientation, but doing this can then cause other issues such as the need for longer control cables or the exhaust exiting in an undesirable direction such as right against the bag)

- Throttle cable and flywheel brake (or compliance) cable connections

- Motor base mounting (not usually a problem - worst-case, you may have to drill another hole in the deck)


It's probably not cost-effective (if you have a shop do it) but you can get your bent crankshaft replaced in your existing motor, or even do it yourself. There are plenty of how-to videos on Youtube that can show you how. That way, you don't have to worry about any of the above-listed items.

 

[mechanic mark]

I will check the oil tomorrow, but I did try a new blade and it didnt change anything.

Post engine numbers model 12H802, type xxxx, trim xx, thanks.

http://evanosaurus.com/ebooks/270962 Single Cylinder L-Head BRIGGS & STRATTON.pdf your engine manual.