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Valve Chatter & Valve Clearance


RTmutter

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I’m getting a few miles in on my new to me 2015 R1200RT (17K miles). I am sometimes hearing what I think is chattering from the valves. I did a valve clearance check. The exhaust valves were all in the .35mm to .36mm range (nice). The intake valves were all in the .104mm to .108mm range. Those are my interpolated or estimated readings going by feel. However, I am confident that all of the intake valve readings were above the .10mm minimum value. Would having the intake valves at the low end of the spec range cause valve chatter? Also, do the intake valves typically tighten up over time? I am wondering whether I should change the intake shims to get the readings a little farther away from minimum or am I good for the time being. Any thoughts?

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I ran out the fuel that the previous owner had in the tank when I purchased the bike. It likely had been in there over winter. I fillled up with 89 octane and added about 6 oz of Techron concentrate. I have done about 200 miles on the new gas with Techron. Maybe I need to get a few more tanks of fresh gas run through it to see if anything changes???

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Probably nothing to worry about. These bikes have a sound that is similar to spark knock/clatter. Not sure where it is from, but changing valve clearance didn't change it on mine. 89 octane might be alright, but 91 or higher is what is recommended. 

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William, 

My target clearance for both the 1200 WetHead and the 1250 ShiftHead is 0.12mm for Intake and 0.36mm for Exhaust.

That's what has yielded the least complaints from owners for valve noise and also the longest time before they will most likely need any shims changed since my experience has been that the valve clearances OPEN throughout life.

Brad

https://drive.google.com/file/d/1DsICPjq8w0WiWAdQbXtG9Sm_P3feEUKg/view?usp=share_link 

i-rtqZvGH-M.jpg

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OK. I think I will stay put for now as far as shims go and keep an eye on the valve clearances over time. If the intakes open up that will be in my favor. I also will look at the 91 octane and see if that makes a difference over a few tanks of gas. Thanks for the info everyone.

BTW, I did use Boxflyer's valve clearance worksheet, it keeps everything organized and clear as a bell. Thank you Boxflyer!

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2 hours ago, RTmutter said:

I fillled up with 89 octane

As Realshelby said the Waterhead boxer motors do make noticeable clatter in general, so that might be something to consider.  I assume that is 89 AKI, you filled up with which would be the minimum Octane spec for that motor.  I think there are also knock sensors that retard the timing more if it knocks as well, and that should be only momentary as the engine management adjusts the timing to stop the knock.   There likely is a bit of a performance hit running minimum octane fuel though.  Running a higher octane fuel might not get rid of any clatter, but will definitely get the most power out of what this motor can deliver. I have notice a bit more oomph by running high quality premium fuel of at least 91octane, or higher if you can find it.

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I don't think there is a knock sensor on the WetHeads.

That was last on the HexHead and CamHead 1200's as far as I can find on all the parts fiche.

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Hmm, thought I readway back in 2015 when I was shopping for my Wethead it did use knock sensors.  I sure won’t bet the farm on that though.  In any case,  my seat of pants experience tells me my Waterhead has more oomph with 91+ octane fuel.  Haha, prolly somebody around here will post some dyno charts to show my butt isn’t well calibrated either.

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16 minutes ago, Paul De said:

Hmm, thought I readway back in 2015 when I was shopping for my Wethead it did use knock sensors.  I sure won’t bet the farm on that though.  In any case,  my seat of pants experience tells me my Waterhead has more oomph with 91+ octane fuel.  Haha, prolly somebody around here will post some dyno charts to show my butt isn’t well calibrated either.

Afternoon Paul

 

There are no actual piezo knock sensors on the wethead. I read a BMW internal letter early on just before the wethead release that BMW engineering stated the new design combustion chambers didn't require them. 

 

There is a way to use the spark plugs as knock sensors (high frequency across the electrode gap) but I don't see anything extra with the coil wiring so this system doesn't seem to be used on the wethead.  

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5 hours ago, realshelby said:

...89 octane might be alright, but 91 or higher is what is recommended. 

Well, I have a 2015 R1200 GS Adventure, and the recommended fuel in the owner's manual is 89 AKI.  I have to believe the RT would be the same?

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30 minutes ago, marcopolo said:

Well, I have a 2015 R1200 GS Adventure, and the recommended fuel in the maual is 89 AKI.  I have to believe the RT would be the same?

As usual BMW makes things a little confusing.  My OM for my 2015 RT says

 

super unleaded ( max 10% Ethanol, E10)

95 Roz/Ron

89AKI

 

I've read that 95 Ron is equivalent to 91 Octane in the old school octane system and AKI is an average of RON and MON (what ever that is) and the best I can figure 89 AKI is equivalent to 92-Octane.  I guess the clearest part of the spec is  to use "Super Unleaded"

 

image.png.b6e2cbf122ff6295ba10b517684acb10.png

 

 

 

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15 hours ago, Boxflyer said:

As @nh1200c has pointed out to me, the 1250 has a Ping Sensor  11 11 7 664 361, so it's just the 1200 WetHead without one.

Morning  Boxflyer

 

Yes, makes you wonder if BMW learned something with the wetheads. BMW did the same thing with the 700/800 (F) bikes. The 700/800  engines didn't have a knock sensor (my 800GS has always had a little throttle-up burst spark knock under just the right conditions). BMW added the knock sensor back in on the later 750 & 850 (F) bikes.  

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My RT is just for fun. I only do 4000-5000 miles a year. I get between 45 and 52 mpg; therefore my annual gas bill isn’t much. I buy the very best gas I can find. It’s usually premium Chevron which has Techron. No ping, no clogged injectors, etc. It probably cost me an extra $3-$5 per tank. If I did 10k miles or more I might buy a cheaper grade, but for recreation… peace of mind. 

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I always thought the knock sensor was helpful when your had no option but regular gas 87 octane, it helped prevent damage?  True or not? 

 

 

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30 minutes ago, strataj said:

I always thought the knock sensor was helpful when your had no option but regular gas 87 octane, it helped prevent damage?  True or not? 

 

 

That's the purpose......:java:

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1 hour ago, strataj said:

I always thought the knock sensor was helpful when your had no option but regular gas 87 octane, it helped prevent damage?  True or not? 

 

 

Afternoon strataj

 

Helpful, yes  _  mandatory, depends. 

 

If a rider is going to pound a high compression engine at freeway-plus speeds in hot weather then YES knock sensors are big safety net against engine damage.

 

Nibbling around the back roads at light throttle moderate speeds is probably not a big deal with no knock sensors. 

 

I haven't seen many problems associated to no knock sensors on the wetheads but I live in the Midwest with decent fuel quality even in the regular 87 octane version. I do know a few 800 (F bike) riders & a few wethead riders that use mostly regular (87 octane) without any issues but  they are not aggressive or hard riders. Here in upper MidWest this time of year is probably the worst as far a spark knock is concerned as most of the gas stations still have winter blend gasoline in their tanks but we can get a few days in the upper 80's. Winter blend is refined to be easier to ignite in cold weather but is worse as far as knocking goes. 

 

I can't speak to the wethead bikes but can (a little anyhow) to the 700/800 bikes in that they can run into engine knock and (piston damage) if ridden in Mexico or South America on the very low quality gasoline available in some places  down there. 

 

BWM seems so have gotten the wethead right (at least for USA/Canada as there doesn't seem to be many complaints about pre-ignition piston or spark plug electrode damage.

 

I'm not sure how they are doing with the GS wetheads ridden hard, or really heavily loaded, in 3rd world countries with only low quality gasoline available  (I haven't heard much on this but sometimes these things don't get reported). 

 

 

 

 

 

 

 

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19 hours ago, marcopolo said:

Well, I have a 2015 R1200 GS Adventure, and the recommended fuel in the owner's manual is 89 AKI.  I have to believe the RT would be the same?

I could be wrong. Might be thinking of the Wifes X3. But I thought I remembered a sticker on my tank ( long since removed) that said 91 min octane. I did NOT confirm it in an owners manual before posting. 

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Directly out of my manual...  I really like the last sentence.

 

Refuelling
Fuel grade
For optimum fuel consumption,
fuel should be sulphur-free or
with the lowest sulphur content
possible.
Leaded fuel will destroy the
catalytic converter.
Do not attempt to run the vehicle
on leaded fuel or fuel with metallic
additives, e.g. manganese or
iron.
You can run the engine on fuel
with a maximum ethanol content
of 10 %, i.e. E10.
Recommended fuel
grade
Super unleaded (max. 10 %
ethanol, E10)
95 ROZ/RON
89 AKI
Refuelling
Fuel is highly flammable.

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I recall that when the LC GS was introduced there was discussion about the lack of knock sensors and mention of adjustments that could be made by a dealer if the bike was going to be used in areas with low octane gas. I never heard of anyone actually having that done, but I presume it involved retarding the timing.

 

I'm kind of glad my Hexhead has knock sensors, just for the peace of mind when I have no choice but to use 87 AKI gas. 

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On 3/26/2023 at 6:30 PM, lkraus said:

I recall that when the LC GS was introduced there was discussion about the lack of knock sensors and mention of adjustments that could be made by a dealer if the bike was going to be used in areas with low octane gas. I never heard of anyone actually having that done, but I presume it involved retarding the timing.

 

I'm kind of glad my Hexhead has knock sensors, just for the peace of mind when I have no choice but to use 87 AKI gas. 

I have read you can have a fuel map flashed  from a BMW Dealer for low octane areas.  I would think there are many areas in the world where your lucky to get gas, let alone 91 octane.

 

The old octane debate, riding season is close :whistle:

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46 minutes ago, LAF said:

I have read you can have a fuel map flashed  from a BMW Dealer for low octane areas.  I would think there are many areas in the world where your lucky to get gas, let alone 91 octane.

 

The old octane debate, riding season is close :whistle:

Morning LAF

 

Yes that is (was anyhow) a dealer only thing as long as you could get to a dealer in the country that you are riding in & they have the ability to do it CORRECTLY.

 

There was some talk that option was possibly going to be in one of the new GS-911 updates, I updated my GS-911 a while back but I haven't looked to see if that function is in that last update.   

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I ran my 2014 R1200GS on 87 octane for tens of thousands of miles without problems although the manual recommended 89 or higher. I originally tried 87 when mid-grade and premium were hard to find because of hurricane damage to some of the refineries. At the time there were several posters on advrider.com who claimed to be using 87 without problems so decided to try it. Never had any problems so I continued to use it even after higher octane became easy to find . Bike was still running fine at 132k miles when I sold it. I think BMW specifically approved 87 on some of the later years of the R1200GS.

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From my 17 GS:

 

Fuel
Recommended fuel quality Super unleaded (max. 10 % ethanol, E10)
89 AKI (95 ROZ/RON)
89 AKI
Alternative fuel quality Regular unleaded (restrictions with regard to
power and fuel consumption. If the engine
should for example be operated with 91 RON in
countries with lower fuel quality, the motorcycle
must be respectively programmed first by your
authorized BMW Motorrad retailer.)
87 AKI (91 ROZ/RON)
87 AKI
Usable fuel quantity Approx. 5.3 gal (Approx. 20 l)
Reserve fuel quantity Approx. 1.1 gal (Approx. 4 l

 

I always read this as a listing of preferred fuel, working down to what is the least acceptable by BMW. 

 

And it seems most gloss over the first line with the word RECOMMENDED.  Super unleaded IMHO is 93.  Premium Unleaded is 91.  But that is how I see it.

 

I was on a 28 day ride and I think in Colorado I pulled up to a pump and it had 85 octane.  Being from the East I had never seen that low of octane.  Explanation is at altitude you do not need high octane gas.  I think I put 87 in.

 

Now my bike is dyno tuned, running a PC 5 so I run 91 or 93. I still get 42-46 MPG if I can control my right hand.

 

All that said, I will run anything I have to to not run out.  All you have to do is not run the RPM and beat on the bike when it has a lower octane fuel in it.

 

With no knock sensors it does not pay to run a bike hard on lower quality fuel.  And in the case of a GS, I would not fill it with 87 and go run one track trails, in Enduro Pro Mode with it,  but that is just me.

 

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