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quickrick_gw

3/4 inch to 1 inch motor shaft retrofit

quickrick
12 years ago

Guys,

My 6 hp Tecumseh motor OHH60, was by specs a 3/4 inch shafted motor but is "special" and turns out to be a 1 inch. I wasn't aware of it and ordered a 6 hp 3/4 inch shaft Subaru Robin.

Can you tell me if you have had any luck making this upsize mod. I hate to return the motor. (I don't think they will receive it frankly)

My plan is to use a 3/4 inch to 1 inch bushing with a slot for the keyway, to bush up the shaft. The impeller of the Cyclone Leaf Rake doesn't come in a 3/4 inch size and that's not an option.

I'd appreciate any feedback.

QR

Comments (12)

  • tomplum
    12 years ago

    I'm sure there is a way, but I would be concerned about the shaft size / strength for your unit. There just may be a reason that they spec them at 1". Worth a call to them.

  • rustyj14
    12 years ago

    Me? I'd be willing to try it! I've done some things like that, and have had no problems with them. Heck, take a chance and try it. RJ

  • quickrick
    Original Author
    12 years ago

    Yeah RJ,

    I'm inclined to go for it now.
    If I could go back in time I'd buy a 1 inch shafted Briggs in 6.5 hp. They do make such a beast but they are rare. The Robin comes in a 9hp version with this 1" shaft but the height and mounting are different because it is physically bigger.
    This motor has lots of cool features...not just OHV but overhead cam chain driven, extra cooling vanes all over and ball bearings on BOTH ends of the crank.

    QR

  • andyma_gw
    12 years ago

    Another vote for an adapter.

  • tomplum
    12 years ago

    I think if you are talking a plastic impeller here then your chances are better than a heavy steel one. Spinning things breaking free at high speeds aren't a good thing. I wonder if an actual adapter like that is made or if it needs to be made.

  • andyma_gw
    12 years ago

    Plastic would work aluminum, copper, bronze brass, or steel. 3/4 id to 1 inch. cut a slot for the key way. An 1/8 wall thickness would make make for a pretty rugged bushing. I used a sliver of 1/2" id copper tubing to make a bushing to fit a 5/8 blade for a 1/2" saw arbor. So far, so good. The key is the main deal.

  • quickrick
    Original Author
    12 years ago

    Tom,

    WW Grangers sells a bushing kit and stepped keys that are made to lick this problem. I am realistic about what I pick up with the vacuum and it isn't stones and bricks but leaves and twigs. With the nylon impeller I think it won't be too harsh.

    QR

  • vinnypic
    12 years ago

    Hey guys, after reading your post's I just wanted you to know they do make a steel keyed bushing that sleeve's down a 1" to 3/4" bore & it comes with the key. I work at a Power Transmission Co. & we sell those. Let me state I'm not trying to sell anything on this website, just wanted you to know they are available just for that size. It's made by Browning & I think the p/n is FHP4K for the 1" to 3/4" bore. But also, after reading Rick's intial post I'm not sure what were trying to bush down, usually those bushings go into sheaves that are to big when somebody replaces a motor or something of that nature, but if your trying to couple shafts together, they sell Lovjoy couplings for those two sizes. Again, not trying to sell anything, just trying to help out. Good luck, Vince

  • quickrick
    Original Author
    12 years ago

    Lawnboy,

    Yup, you nailed it. That's exactly the right bushing! I looked that one up and while what Graingers sells is similar, I like your Browning's stepped key that is designed to fit this set-up. I'm doing 2 separate products.
    I may have to mess around with the slot and the fit of the 3/16 to 1/4 inch stepped key stock I am buying. I will definitely hang onto this in my favorites. I will contact you if what is coming doesn't pan out...wish that I knew sooner, hehe!

    Thanks,

    QR

  • vinnypic
    12 years ago

    Thanks QR, and If you hit a road block & need something just let me know.
    Vince

  • quickrick
    Original Author
    12 years ago

    Lawnboy and guys,

    We will see if the WW Grainger parts, which are in, work as expected. I will pick them up tomorrow and should be able to mess with the thing tomorrow after work.

    If all isn't kosher, I need to order the better stuff from you at your shop Lawnboy. Still, it is nice to know where and how to best tackle these problems...I rather enjoy a challenge.

    QR

  • quickrick
    Original Author
    12 years ago

    Guys,

    I wanted to update you on the retrofit of the Subaru motor to the Cyclone Leaf Rake. I finally got the parts and made time to adapt the thing. While I am sure that Lawnboyforever's parts are better than the kit I made, mine seemed to do the job. My one area of concern is the impeller bolt. It is one size smaller than before, the shaft is a bit shorter and the one I found is not a grade 8. I put Locktite on the threads and will get a grade 8 bolt soon to replace this one.
    The engine runs quietly and efficiently as I used it to do the yard for 4 hours today. It used a small amount of oil but I guess that is to be expected. I had no vibration problems or wobble of the impeller so I may be in okay shape for now. Check out the pics!
    Thanks for all of your support,
    QuickRick

    Here is a link that might be useful: Cyclone Leaf Rake