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Thread: Spark plug and air filter - real life change intervals?? - 2011 R1200GS

  1. #1
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    Question Spark plug and air filter - real life change intervals?? - 2011 R1200GS

    G'day,

    BMW recommends changing the spark plugs and the air filter every 20,000 km. But to me, they both look good after 20,000 km...the bike starts immediately, runs strong, runs smooth, lots of power, good fuel economy...so I am asking myself why spend $100+ if I don't really need to change them after 20,000 km??

    Just wondering how often other people are changing their:
    1. Spark plugs
    2. Air filter

    Thanks for any feedback.

    Dave McDougall
    2011 R1200GS
    Welland, Ontario
    Canada

  2. #2
    A bozo on the bus deilenberger's Avatar
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    Air-filter really depends on the environment you're using the bike in. If you're doing lots of off-road riding in dusty conditions, the 20km recommendation may be not frequent enough. If you're doing all street riding, I'd be comfortable with 24,000 mile changes.

    Plugs - dunno since I suspect your '11 has the camhead engine, which uses a different plug then the hexhead. On the hexheads I've changed them at around 24,000 mile intervals and haven't experienced any problems I could attribute to that change interval.
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders New Sweden BMW Riders
    '07 R1200R (current ride) and some bimmers.. and a Porsche

  3. #3
    Registered User f14rio's Avatar
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    seems to me

    if it starts okay, runs smooth and the mpg hasn't changed...from a practical aspect, nothing is required except maybe a removal, visual inspection and gap check.
    "Enemy fighters at 2 o'clock!...Roger, What should i do until then?"

    2010 r1200r, 2009 harley crossbones, 2008 triumph/sidecar, 1970 norton commando 750

  4. #4
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    Now for some data

    Re plugs
    On hexheads, spec is 0.8mm with a 1.0 mm wear limit. The reason for the wear limit IS NOT the typically assumed one- that the bike won't start or run decently at a larger gap- in fact it will. If I had to guess what the limit that would impact starting is, I'm sure its well over 2 mm which, allowing for some guesstimating due to changing wear rates at larger gaps, would likely take 80K miles or more..
    BUT, the larger gap makes it harder for the stick coil to generate the needed juice so puts more "wear and tear" on the coil. The reason for the spec is preservation of the life of the coil- which is a good deal more expensive than the plug and can only be troubleshooted accurately by substitution- simply grounding a plug to the block does not tell you if its firing properly on modern ignitions.

    Actual measurements on my own hexhead show that plugs do in fact reach the factory set wear limit at the factory change interval. I have no reason to believe camhead specs would be incorrectly set by the factory but if you want to run them at larger gaps and see if your stick coil eventually fails, have at it. A little search should find you the photos I posted here of plug wear. Note that at changes that modest wear you need to MEASURE, not just look, and that the dual electrode design of many BMW plugs means you need wire gauges because flat feeler gauges won't fit properly to give accurate measurement.

    Re filters
    At one point in my life I ran a filter test lab. The factory limits are conservative and come from data the requires lab instruments to set.
    Key filter test data include ultimate dirt holding capacity, etc but for air filters, life is set of a pressure drop spec vs anticipated dirt loadings- to preserve engine power and fuel economy. Then there is the physical damage vs time concern that the typical air filtration material can be physically damaged by a lot of abrasive grit over time and you don't want those large particles getting past an old filter and into the motor (though bypassing often happens because gasket areas aren't properly cleaned and sealed at filter change). Obviously extrapolation of the lab data can only work with what can typically expected in the real world so any factory recommendation is just that. The worst that can happen if you run it too long is a little loss of power and economy with no real way to predict how much and when- certainly nothing obvious will happen until the filter is well beyond its recommended change mileage unless you run in an extremely dirty place which is unlikely. Urban environments tend to have a lot of dust and grit churned up by constant vehicle traffic so many put more junk on your filter than you think. For myself, I just change at or near the factory interval- its not a big deal and not a big expense. The usual comment about an expensive bike and cheap parts applies here as well as one noting that, unlike some other specs, filter life specs tend to be pretty uniform from one manufacturer to another.

  5. #5
    MOA #24991 Pauls1150's Avatar
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    I've had air filters collect very significant dirt/etc well before 10,000 miles, so I have no issue changing it on an "as required" basis.
    Re-gapping worn plugs has given me easier starting and a smoother idle, but after the first re-gap, it's time to change 'em. The NGKs I use in my 1150 get tossed at or before 20,000 miles.

  6. #6
    Registered User lkchris's Avatar
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    BMW plugs these days come pre-gapped and with instructions not to attempt gapping. This stuff is ancient history.

    Camhead plugs are REALLY small and the change interval is 1/2 that of hexhead changes ... the size probably having lots to do with that.

    To me it seems like "cult" behaviour to try to come up with ways to save money on BMW ownership and then brag about it to others. Motorcycles are for fun and I see no reason to feel guilt about money spent on them. Planning for this ought to be part of the purchase decision. BMW are the best and are produced by the best engineers and their maintenance recommendations are the best as well. Pretty much nothing about BMW ownership is anything but expensive. The fun's supposed to make it worth it. Thinking motorcycle ownership "economical" is fantasy.

    Well, the recommendations are the best save for their motor oil change recommended intervals. The short intervals allow them to appease those that would use conventional oils, I suppose. (They certainly don't allow their car owners this silliness.) Also, I think they assume changes at BMW dealers and it's probably best for everyone's safety that dealers see the bikes as often as possible. I think that's the reasoning behind the short intervals, but this thread indicates there is demand out there for reduced maintenance requirements just as there are with cars.
    Kent Christensen
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  7. #7
    God? What god? roborider's Avatar
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    I have a hex head. I bleed the ABS unit every year. At that point, I change the filter regardless since I've done all the work to get there. I can't say my filter has ever looked dirty enough to worry about. This is about a 10 - 12 k mile change as I ride 10-12k miles a year.

    Since I have a hex head, my plug data is irrelevant to the Cam head. But I change about 20-24k miles on my plugs which is BMW spec.
    Rob C. , Raleigh, NC
    '10 R12RT, R90/6
    2007 CBR600RR & 09 V-Star
    Suzuki DR 350

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    I just had the 24 K service done on my 08 GS by Blue Moon of Norcross (where the bike had been serviced by PO). I asked them to save the old plugs and air filter so I could have some reference points. I do the 6ks and let the dealer do the 12Ks. The filter and plugs were clean, plugs white and toasty brown tips, I did not check the gaps but I will. The bike ran good but now runs super. I suspect its due th the sum of all stuff done but was well worth the cost for ride improvement and peace of mind

  9. #9
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    I like Kent's coments on oil changes.

    The guys who change oil every 3K on their bikes would die if they looked at the oil in my VW TDI. Like any diesel, the oil is black from carbon immediately after any oil change- takes almost zero miles. But modern oils deal with it just fine- factoy change interval is 10K or annually. VW actually has a unique oil spec for the current TDI just to match its design with low sulfur modern diesel fuel which has less inherent top end lubrication. But boy is that oil ugly compared to anything you could see in an R bike.

    My R bikes get oil changes about every 8K or so and I don't worry. Pretty much every published oil analysis shows this is a reasonable interval with good oils and the separate tranny, large oil capacity, small displacment, typical oil temps, and other design factors support it also. I'll bet if I wanted to really stretch it and spend $$ on lots of analysis, the data would show a 10-12K change interval to be fine with many oils, maybe even 15K. But no reason to do it- bikes, like any machine, need some periodic attention to run at their best and oil is cheaper.

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