What's the difference in B/S 6.5 motors?

Discussion in 'Mechanic and Repair' started by rh455, Feb 11, 2008.

  1. rh455

    rh455 LawnSite Member
    Messages: 12

    I have a Snapper self propelled walk behind with a B/S 6.5 Quantum(I think). I think the compression is getting down a bit as it's hard to start. It takes up to 15+ pulls to get it running. I am considering repowering it with another B/S 6.5, but I see there's a difference in 6.5's available. One has OHV and iron bore while the others(cheaper) does not have OHV and it says "aluminum bore". Is that possible to have an aluminum bore? I thought they were all iron sleeves. These are the two that I'm considering.........

    Aluminum bore model(my existing one looks like this)

    Cast Iron bore:

    My existing motor looks like the aluminum bore motor, but I'm pretty sure it's a cast iron I/C motor. Is the new replacement just a throw away motor now?
  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

  3. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Messages: 964

    If you're only talking about $20 or so, get the OHV/Iron bore.
    An OHV has a MUCH better torque curve vs an equivalen HP Flathead.

    BTW, your links don't work. What are the actual number from SEW?
  4. MuleCutter

    MuleCutter LawnSite Member
    Messages: 212

    yes... the cheaper ones do have an entire aluminum block... including the bore. if you have a choice DEFINITELY get the iron bore. if you can find and Quantum I/C engine, which they dont make anymore, that's left over in a shop and hasnt been sold get it. it has an iron bore and has good power also. plus you dont have OHV on it so it's easy to work on. either one that you get isnt worth getting fixed (unless you can fix them yourself) because most of the time the repairs cost more than an entirely new engine.
  5. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    You have to look that up, the link does work but without the model number I don't feel comfortable giving a direct link to any one engine because it could be the wrong one... So with that link I gave you the whole page of engines...
    If it didn't work maybe SEW was down, but I just clicked it, there it was...

    This model number I speak of is stamped on the Valve cover of the briggs.
    Once we have that it should be easier.
  6. rh455

    rh455 LawnSite Member
    Messages: 12

    Thanks for the replies guys. I went to the house and looked at the motor. It's a 6hp flat head design. I guess it's an all aluminum engine originally. It had the Snapper cover on it, so I don't know if it's a Quantum or not. I thought it was an I/C motor, but it's been so long since I bought it that I can't remember. The original model # is 12H802 and type # 1987B1. I did find a 6hp on the SEW page with a starter on it for $175, but it's the flat head type which I assume all were aluminum bore. It looks identical to what I have, but with electric start. I may call them to see if it comes with the starter like the photo shows. If it does, then I may buy that since my mother is 71 and still insists on cutting her own grass. She just bought a John Deere similar to the Snapper, but I don't want the Snapper going to waste since it's in great shape. I'd like to convert it to elect start, but have to do more research into the key switch, battery, cables etc.

  7. rh455

    rh455 LawnSite Member
    Messages: 12

  8. Jay Ray

    Jay Ray LawnSite Fanatic
    Messages: 6,510

    Some Snappers come with a 7/8" crank stub and some with 25mm. If you get the same stub diameter (and length) you can use the old pulley and blade adaptor, not have to buy new ones from a dealer. The pulley uses a woodruff key and you need that key slot to match your old engine also. It's a pain but best to remove the old motor, mic it and sketch the stub before ordering a new one.

    And the cast iron sleeve wears better if you can find it at a good price. Hard to beat SEW just like Topsites said.

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