B&S 18hp twin longevity

Discussion in 'Mechanic and Repair' started by Pahoia2, Nov 4, 2001.

  1. Pahoia2

    Pahoia2 LawnSite Member
    Messages: 13

    Hi there,

    I have a B & S 18hp I/C flat opposed twin (boxer type) with vertical shaft on my Murray mower. After seven years of almost daily use as a small tractor, as well as cutting two and a half acres of grass in a country where that's an all year round, weekly job, I'm beginning to wonder how much more service I can reasonably expect from it before things start going wrong. I've always changed the oil at least twice a year, sometimes more, and used B & S's own 30w oil. So far it's going as well as when it was new.

    Where do these engines sit in the B&S line up in terms of ruggidness and durability? What gives up first on them? Is the branded B&S oil (the red stuff) any better than any other major brand's 30w oil?

    I'd be interested in the experience of others with these engines.
    (Go on, tell me it's the worst engine B&S ever made!)

  2. justractors

    justractors LawnSite Member
    Messages: 39

    It seems to me that if you have already gottn seven years out of this engine and tractor combination then you have already gotten your money's worth.
    I am wondering if you still have the same car, boat, clothes washer and dryer,etc that you had seven years ago.
    The semi annual oil changes are way too few for the number of hours you say you are putting on it since I believe B&S recommends 50 hours on oil changes for this engine unless it has the oil filter which then has 100 hours on oil changes. Also the additives in engine oil, once esposed to air, do break down with age whether it is used or not and that is why oil manufacturers recommend 3 month oil changes. But if it has gotten you this far it must be working.
    As far as the type of oil there are as many opinions out there as there are oil brands. But again if it ain't broke why fix it? I personally recommend a good synthetic oil due to the heat build up in these small engines especially with your infrequent oil changes.
    I would not be overly concerned about the engine failing any time soon as long as it is not knocking or smoking and as long as it continues to run well.
    I would recommend that you start doing oil changes every three months instead of every six months however. Keep using a good quality engine oil and keep the engine running as cool as possible by keeping it clean and cleaning the air filter often.
    Good luck,
  3. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    It sounds like you have kept up on the maintance.Clean air fins,and shround,clean air filters,and regualr oil changes go a long way.If its running fine,I would think you could get another 3 yrs at least out of it.Is it using any oil?is it leaking oil,or showing any signs of wear?If not,I think its in good shape.My Onan's gice several warnings as they get tired,I know the signs now,since ive been thru a few of them.
  4. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Messages: 342

    ok. heres the specs on your engine:

    #1 quiet performance
    #2 Dura Bore cast iron cylinder sleeves
    #3 Cobalite exaust valves
    #4 mechanical governor
    #5 Magnetron electronic ignition
    #6 dual clean air filter
    #7 lube power lubrication system
    #8 high oil fill with automotive type dipstick
    #9 2 year engine warranty for consumer use, 1 year for commercial use.
    Thats it!! whew!!!
  5. justractors

    justractors LawnSite Member
    Messages: 39

    I hate to say anything but these are the "Features" and not the "Specs".
  6. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Messages: 342

    sorry. i usually get confused with those type of things.
  7. khouse

    khouse LawnSite Bronze Member
    Messages: 1,465

    The only thing that I've found is that the coils go bad once in a while. Also there is a small metal cooling shield under each cylinder that need to be removed and cleaned. It gets packed in there. Otherwise a nice smooth running engine.
  8. Pahoia2

    Pahoia2 LawnSite Member
    Messages: 13

    Thanks for the replies.

    Maybe the 18hp B&S isn't one of their more popular engines. I guess the Vanguards with their better lubrication systems are better engines. Still I can't complain about mine. I think Bill from 'justractors' has a point about oil changes and I'll increase mine from the present two a year. I always keep the cooling fins clean but I'll have a look behind those shields 'khouse' mentions under the cylinders and give them a clean out. I change the air filter from time to time. The only engine problem I can remember in the last seven years is the starter. I had to replace it a couple of years ago.

    Otherwise, I think it's a good engine. I also have a small 3.5hp B&S on a sprayer. It's fairly new though - done less than a year - so I can't comment on it's serviceability yet. So far so good.

    I think I'm becoming a B&S fan!


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