Pressure washer motor on a mower

[Sweet Leaf]

I'm want to replace my old B&S lawn mower motor with a Honda GCV160 that I have acquired. The Honda is from a pressure washer so I am trying to figure out what parts I will need. I know I will need a flywheel brake. Second issue is how to mount the blade. The shaft is keyed, there is no threaded hole in it. I'm thinking I can use some kind of blade adapter and drill and tap the shaft to mount the blade/adapter. Anyone know if this can work and what parts I would need? Thanks.

 

[bertsmobile1]

forget it you are on a hiding to nothing
That sized engines are available everywhere for a song
By the time you have drilled and tapped the hardened forged steel PTO shaft you could have just about bought a new motor

 

[Sweet Leaf]

The cost for a new motor is not an option for me at this time. I have not had any luck finding a used motor. I have nothing to lose trying to drill the shaft since i have the motor. Anyone else have any ideas? Is there an adapter available to mount a blade on a keyed shaft?

 

[d_sharier]

I agree with bertsmobile1. Not to be negative or to say it can't be done. There are so many things to take into account. Drilling and tapping tool hardened steel is a feet in itself. It can be done but the crankshaft would need to be removed from the engine. It would take a access to a milling machine / Bridgeport / something .... will need a ton of coolant and more than an average drill bit. Let's say for the sake of argument that you are able to get some sort of hole in the end with a drill, and even tap that hole, if it is not dead on center all sorts of problems will arise. Engine vibration, etc. etc. Most concerning would be the chance of compromising the integrity of the metal while drilling the hole. The experience of a crankshaft exploding at 3,600 rpm is like no other! The other things to look at are the crank diameter? Also, the length of the crankshaft (PTO) extending through the bottom. If the length is not the same you can spend a countless amount of time trying to find a blade adapter that will fit, and make up the remaining balance of length. Too short and it doesn't cut or discharge correctly. Too long and it may hit the ground.

If you are dead set on trying to drill it, I would offer this advice: Buy a short length of 5/8 or even 3/4 stock rod. Most hardware stores will sell it. It is not hardened so it will be significantly easier to "mess" with. Run a trial on it. Try to put an inch or 1.5 inch hole directly in the center and tap it. Then get some measuring tools and see how it comes out. That way if you find it next to impossible, then you are only out a few bucks in metal. I have ruined a few completely good engines trying to "fabricate" and in my experience it only adds insult to injury.

I don't know where you are located but in my area, mower engines are a dime a dozen. In all things, the worst time to try to find/buy is when you need it. But used mower engines should be around and relatively inexpensive. I'll bet the second you aren't in a hurry to find one, they will manifest out of thin air. (at least it seems to work that way for me)

Lastly, what kind of mower are you working on? I know you said a Briggs engine, but what brand is the mower?

This is just my shared experience. Take it or leave it. Whatever the choice, I hope it works out for you.

 

[reynoldston]

It looks to me like you have nothing to lose, I say go for it. You have a extra engine with no use for it anyways. So if you are off center a little, your not that high of RPM to matter that much, just make the blade adapter hole a little bigger and use a flat washer if its out of center. Its not a race engine its a mower engine. Myself I have never tried to drill a crankshaft so I don't know how hard they are but you don't know unless you try. Best Of luck :thumbsup:

 

[Sweet Leaf]

Thanks for all the input, I had not considered that the shaft was hardened so this gives me something to think about. I have the spare motor so nothing lost if I fail, so I will try drilling it. The mower is a John Deere with a cast aluminum deck. I'm not sure what the bolt size will be so I will probably have to buy the adapter first. I did a search on blade adapter and a lot came up but I don't know which one I'll need. Might have to take the motor to a repair shop and see if they have something.

 

[robert@honda]

So about that Honda engine off a pressure-washer...is the engine a horizontal or vertical shaft version? (Both are sold on pressure washers).

If it is a vertical-shaft (like a mower engine) you might get away with replacing the crankshaft with the correct type/end. The flywheel brake parts are not too expensive...