will I have to replace crank shaft?

[T-LeDoux]

Hi I bought a Briggs engine at a scrap yard Family-YBSXS.5012vp 274826 model-31N707 Type-0233E1 Code 0311177E . When they cut the engine off the mower they cut one of the pulleys off. I read some where you can not run a lawn mower engine with the blade off because it will through off the balance. So If I can get this engine running, will the engine run with the piece of crank shaft missing? or will it be so out of balance it will need to be rebuilt and have a new crank replaced.

 

[91c1500]

The blade does help with balancing the engine so it will need a new crankshaft. You could probably run the engine for a test run but it'd probably shake pretty bad and might even throw something. It's not recommended to run the engine at all really without the blade.

Why do you want to run it without a blade anyway?

 

[KennyV]

The blade actually acts as a flywheel... It may be very hard to get it to start with out the weight of a blade to keep up the momentum needed to start... :smile:KennyV

 

[ILENGINE]

Guys the 31N707 is a rider engine, not a push mower engine. You can run the engine without anything attached to the crankshaft. Go ahead and get the engine running off the mower, it will run fine, with some vibration, but not excessive.

 

[T-LeDoux]

Thanks to you all for your replies, I guess I need to word my questions better so there is no confusion. Again thanks for the comments.