Rattle in my '07 R1200S

drcrippen · 06-07-2012, 07:03 AM

Recently purchased a very nice '07 R1200s. However, I have noticed when I start off in gear there is what appears to be a rattle sound from the engine, maybe transmission. Sounds actually like a loose chain or something like it. Settles down once higher RPMs or constant speed is reached. Not noted at speeds as high as 90 mph. Only when running through first and second gear. Disappears when not loading the engine. And I have also noticed that the engine backfires when coming down hills with the throttle down.

It's hard to tell if this is pre-detonation because I don't really know what that sounds like. The only gas available to me is 93 octane. The engine otherwise runs fine. Seems like I read somewhere that this model has some extraneous sounds due to the hopped up engine.

Any ideas?

Thanks in advance.

signit98 · 06-07-2012, 08:12 AM

The backfire is likely a sign of running a bit on the lean side... a good remedy is to get a fuel management tool (i.e. Techlusion, PCIII etc) and dial it in.

It is hard to internet-diagnose a "rattle" sound in an engine. The boxers are prone to run a little louder, but the fact that the sound disappears under certain conditions, makes it a tad more iffy. These particular bikes get a little louder with age, because the clutch gets a little looser. Is there a sound difference in idle between clutch engaged and clutch disengaged?

That's a good indicator.

The other option is, in fact, the timing chain. Go and get new springs for the tensioners and put them in (left side is a bit of a biatch, right side is super easy). That's something you should do after a while anyway. See if that alleviates some of the rattling noises.

Go from there... if that does not work and you bike is doomed... I have made it a mission to help people with doomed bikes and I will generously pay you $1500 for the heap of rubbish. Just let me know where and when to pick it up.

That's how I roll... humanitarian ALL THE WAY!

You are welcome!

Droptarotter · Droptarotter's Garage

Also check this out..........
Loose Trans Bolt

Cheers

drcrippen · 06-07-2012, 09:43 AM

I checked everything and nothing is loose. Plugs do not show evidence of significant leaning. Would running lean cause predetonation?

Main concern is the possibility of pre-detonation? I use 93 octane (only thing available). But this thing has a 12.5 compression ratio. The manual recommends 98 or no less than 95 octane (not available to me ever).

Does anyone think trying "octane booster" (from K-Mart)? Essentually toluene as I recall. DOes this stuff actually increase octane? Safe to try and see what happens?

Noblehops · 06-07-2012, 10:01 AM

Quote:

Originally Posted by drcrippen

I checked everything and nothing is loose. Plugs do not show evidence of significant leaning. Would running lean cause predetonation?

Main concern is the possibility of pre-detonation? I use 93 octane (only thing available). But this thing has a 12.5 compression ratio. The manual recommends 98 or no less than 95 octane (not available to me ever).

Does anyone think trying "octane booster" (from K-Mart)? Essentually toluene as I recall. DOes this stuff actually increase octane? Safe to try and see what happens?

You may be caught in differing methods between the EU and US in measuring octane with that '98' number. If you're running 93 then I think it's safe to assume the fuel is not causing issues.

N.

signit98 · 06-07-2012, 10:28 AM

Yes, to what Nils said... we don't have 98 pump gas here in the US, you are reading euro specs.

You can try octane booster (works well and is safe) for a tank and see what happens, but I really doubt that is your issue.

As for the "running lean" you may not run lean across the rev range, but you might have some lean spots. The R12S is notorious for that, due to EPA strangulations... ahem regulations.

Again, hard to diagnose when one does not know what someone else's perception of "a rattle" is...

Mrmerlin · 06-07-2012, 10:50 AM

since your not really sure of the noise,
why not stop the BMW dealer and have the mechanic come out and take a look/listen

u3b3rg33k · 06-07-2012, 01:10 PM

Two things -
pre-ignition and detonation are two separate issues - you're combining them into one, which they are not.
in short:
Pre-ignition is often when something hot (glowing carbon) causes fuel to ignite sooner than it should. (fits in there with dieseling - which old carbureted cars sometimes did - continuing to run after the engine was shut down. We had a car that did that and it ended up with 265,000 miles on it - no big deal).
Detonation can be really really really really bad. detonation is fuel exploding (not the normal controlled burn).

in the US, we measure octane differently than they do in Europe. They use Only the RON number, which is higher than the MON number. We use AKI, which is (RON+MON)/2. My bike's boilerplate says minimum octane: 91AKI on it. Yours probably says the same thing.

leafman60 · 06-08-2012, 02:59 AM

Diagnosing via internet in this situation is almost impossible. I ditto what someone else said. Take it by a dealer and have them take a listen.

I am dubious about the fuel quality issue. Normally, knocking from this is most evident whenever the engine is under a little bit of labor. I don't think you'd be hearing a constant rattle while idling or running at a constant speed as you imply. It could happen, I guess, but if the fuel there was that bad, many others would be having problems too.

Could be the cam (timing) chain. Could be your valve clearances. Could be many things.

drcrippen · 06-08-2012, 04:21 AM

Thanks for advice. I did run it up to the local BWM dealer and the mechanic rode it. He says I'm too hypersensitive and the rattle is the normal noise of all the reciprocating parts in a boxer engine which sounds different than an in-line. So have arrangement for a full service and maybe that will settle it down.

BTW, he said it is impossible to adjust the onboard "computer" on aR1200S. I'm getting a set of Laser twin undersea exhausts and he said the O2 sensor would automatically adjust for them over the stock muffler.

ckcarr · ckcarr's Garage

My bike used to do that occasionally. Think it was a combination of fuel and heat.

Diagnosing via the internet is what we do on this board, right or wrong.

leafman60 · 06-08-2012, 06:16 AM

Quote:

Originally Posted by drcrippen

Thanks for advice. I did run it up to the local BWM dealer and the mechanic rode it. He says I'm too hypersensitive and the rattle is the normal noise of all the reciprocating parts in a boxer engine which sounds different than an in-line. So have arrangement for a full service and maybe that will settle it down.

BTW, he said it is impossible to adjust the onboard "computer" on aR1200S. I'm getting a set of Laser twin undersea exhausts and he said the O2 sensor would automatically adjust for them over the stock muffler.

Some adjustment is possible but I do not think it is sufficient. I went to a PC and had a noticeable improvement.

RBMann · 06-08-2012, 07:37 AM

Quote:

Originally Posted by ckcarr

Diagnosing via the internet is what we do on this board, right or wrong.

Yes, mechanical and psychological.

AZ-Twin · 06-08-2012, 08:46 AM

Quote:

Originally Posted by drcrippen

Thanks for advice. I did run it up to the local BWM dealer and the mechanic rode it. He says I'm too hypersensitive and the rattle is the normal noise of all the reciprocating parts in a boxer engine which sounds different than an in-line.

LOL. So, I had been riding my R1200S for a few years, then I bought a GSXR 600 for the track. The day I picked it up I remember having to look at the Tachometer to see if it was running.

On my R1200S in the parking lot when it was idling my gloves would fall off the seat, my friend with a GSXR-1000 started his bike one day with his helmet sitting on the seat, I asked if it would fall off and he looked at me like I was nutts.

I miss my R1200S, the bike has a lot of character.

poldar12s · 06-08-2012, 09:51 AM

Quote:

Originally Posted by drcrippen

Sounds actually like a loose chain or something like it. Settles down once higher RPMs or constant speed is reached. Not noted at speeds as high as 90 mph. Only when running through first and second gear. Disappears when not loading the engine. And I have also noticed that the engine backfires when coming down hills with the throttle down.

Been a while to hear first impresstion of the boxer engine. You will like it. Just remember to support your helmet when you put it on the seat. I like the original power band which makes rather gentle and forgiving throttle response (5 to 6k rpm) when leaned.

Noblehops · 06-08-2012, 09:58 AM

Haha!

Paul means, "It's a feature, not a bug"

N.

leafman60 · 06-08-2012, 11:59 AM

One benefit of owning and riding a Harley Shovelhead for 110,000 miles and 35 years is that I pay little attention to "normal" engine mechanical noise !

u3b3rg33k · 06-09-2012, 10:19 AM

Quote:

Originally Posted by AZ-Twin

LOL. So, I had been riding my R1200S for a few years, then I bought a GSXR 600 for the track. The day I picked it up I remember having to look at the Tachometer to see if it was running.

On my R1200S in the parking lot when it was idling my gloves would fall off the seat, my friend with a GSXR-1000 started his bike one day with his helmet sitting on the seat, I asked if it would fall off and he looked at me like I was nutts.

I miss my R1200S, the bike has a lot of character.

Don't forget goosing the throttle when it's on the side stand and watching it move.

blkduc1 · 06-12-2012, 03:39 PM

Quote:

Originally Posted by drcrippen

Recently purchased a very nice '07 R1200s. However, I have noticed when I start off in gear there is what appears to be a rattle sound from the engine, maybe transmission. Any ideas?

Thanks in advance.

DO you have a hugger on the rear? I do and sometimes mine rattles because the rubber bumper is not quite tight enough. An easy fix..... But it really sounds like your rattle is different than that..... or is it?,,,,,,

dp