New honda crank shaft bent: Hard repair for moderate user? Owner scrapped it.

[a_gunslinger]

Someone I know is scrapping a 3 yr old nice shape Honda 3 in 1 mower. Son hit something and bent the crank shaft.

Im not a great mechanic, but not the worst. Done many a dirt bike. For a free mower can a DIYer with basic tools do this job?

Thanks

 

[motoman]

gunslinger, Straightening shafts is art like. I hear it is done, but there is a difference in straightening short term and long term. The successful shops use heat treats to convince the shafts they should stay straight and strong. Not sure it's worth the effort unless obtained free.

 

[bertsmobile1]

Not a job for the home mechanic.
Some shops have a crank straitener tools but as an ex metallurgist I strongly advise against it.
However as a project ( good father & son bonding job ) it would be worthwile getting a replacemnt crank.
Or sending it out to a specialist to have it properly done complete with proper heat treatment.
If you do go through look at fitting a blade carrier & swing back blades, Always a better idea with a direct drive.

 

[ILENGINE]

You have done some mechanic work so this may be within your knowledge. I have found that one some honda engines the crankshaft is cheap enough to replace if you want to do the work yourself. I am sure somebody here could come up with the manuals if you want to go that route.

Just went and checked and the crank for a GCV160 is going for about $38.00

 

[a_gunslinger]

Thanks gentlemen. Correct, I am not looking to straighten it, just take the engine apart and drop a new one - a good father and son project ;^) But if it takes a bunch of special tools and s=uch probably couldn't do it. Will get the exact model.

 

[robert@honda]

Here's a simple exploded diagram of the key parts. Unlike some small gas engines, many Honda mower engines are a diagonal-split block design. They don't have a traditional cylinder head, but use a timing belt design, so still considered overhead valve and overhead cam:

For just a crank R&R, you'd need strap wrench and flywheel puller to get the flywheel off, but otherwise, no special tools really needed. There are some cutters and pilot bars if you ever get into valve reconditioning.

 

[a_gunslinger]

Thanks! I might just give this a try!

 

[OS_Tigger]

I'm about to do the same thing as a_gunslinger. You wouldn't happen to have a shop manual that you could share, would you? I'm a bit concerned about the process of taking the whole mower apart before I get to the point where your diagram will help. Anything would be greatly appreciated!

Here's a simple exploded diagram of the key parts. Unlike some small gas engines, many Honda mower engines are a diagonal-split block design. They don't have a traditional cylinder head, but use a timing belt design, so still considered overhead valve and overhead cam:

For just a crank R&R, you'd need strap wrench and flywheel puller to get the flywheel off, but otherwise, no special tools really needed. There are some cutters and pilot bars if you ever get into valve reconditioning.

 

[robert@honda]

I'm about to do the same thing as a_gunslinger. You wouldn't happen to have a shop manual that you could share, would you?

Honda offers paper copies of all shop manuals through Amazon and eBay (free shipping). Be sure to have your full model and serial numbers (sticker on the back of the mower deck) when you're ready to order, as some manuals only apply to some models...

Honda Power Equipment Shop Manuals on eBay
Honda Power Equipment Shop Manuals on Amazon

 

[Freezn]

Have you given any thought to re-powering the machine with a Honda GCV190? Another more cost effective option might be to re-power with a Honda clone engine like a Predator 5.5hp 173cc engine ($119)