replace crankshaft or trash?

[jch]

Hello everyone,
I was given a 2006 model Snapper with a B&S quantum 6.5hp xrm engine with which a young kid had hit a rock or stump and the machine proceeded to scream when it ran. Rather than toss the mower I thought I would try and fix it cause I am in need of one.
It appeared to me the shaft was warped so i dissassembled the machine and removed the shaft. My question is whether it is economically practical to try and replace this shaft (about $70 for shaft and shop manual) or just buy new mower or engine?
If I did replace the shaft, will "timing" have to be set on the machine and would the manual tell how to do this?
Could the shaft be straightened ?
If I bought a new engine where would I find one(and how much) and could I replace it with a different make, say a Honda?
Lots of questions I know but it appears from previous threads that you guys know Lawnmowers and I hate the thoughts of just trashing a 100lbs. of free lawnmower if it can be fixed. Not to mention I will still have to shell out $300-400 for a new mower.
Thanks for any help.

[fly-4-fun]

If it were mine, I'd replace the crank. The shop manual will tell you how to get the timing marks in the correct place. I wouldn't try to straighten the shaft, it might have a hair line crack and fail big time later on. J Thomas is a great place to buy replacement engines. http://www.j-thomas.com/index.html You could replace it with a different make, just be sure the mounting holes would line up and the shaft length were the same. Just my .02 worth........

[khouse]

How far did you dissasemble the engine. You can leave the head, piston and rod in place to replace the crank. All you really need is the rod torque, base gasket and crank seals and of course the new crank.
Parts can be purchased here.
AES 1-800-843-3546 or at one of the sponsors above.

[Restrorob]

For a few more $ you can buy a new engine with a 1yr. warranty providing your crankshaft measurements are the same.

http://www.smallenginewarehouse.com/product.asp?PN=123K02-9231&desc=Briggs+Stratton+Engine+6+HP+Quantum+Vertical+7+8+x3+5+32+Shaft+for+push+mowers

[Mark in MD]

I agree with Restrorob. I'd have to be either really broke or really have a lot of extra time on my hands to replace a crank.

[KTO Enterprises]

When I was in High school I worked for a mower shop and we had a tool that you bolted the engine to and it would straighten the crank shaft out. I used to do at least 3 a week. Only about 2 of 50 wouldnt straighten. the cranshaft would break and that was not a pleasant sound. Louder than a shotgun going off in your ear.

[Bill Kapaun]

It's rare to find anyone that will straighten a crank anymore. Too many lawyers!