TB Rattling

Topics related to the ownership, maintenance, equipping, operation, and riding of the R1100R.

Moderator: Moderators

Post Reply
currypuff
Basic User
Posts: 3
Joined: Thu Jan 14, 2010 12:36 pm
Donating Member #: 0
Location: Singapore

TB Rattling

Post by currypuff »

Hi all.
There is a rattling sound when my engine was warm. Reading threads from various forums, many seem to have this problem with the LHS cam chain tensioner. I ordered both sides to be sure and replaced the LHS with the improved version last week. Supposedly an hour job but I took longer as I used the opportunity to clean the insides as much as I could.

I read of what a miracle cure this replacement does so imagine my disappointment when there was no improvement to the rattling at all. :x
I then remembered this part called a Ticker Killer in the Motorworks website. Reading up more on it, there are apparently other factors that can cause this. The TK is designed to cure the rattling on the RHS (BMW sure has a sense of humour :-X ) of the TB caused by worn bearings or shaft. So after a ride, I put the bike on the center stand, start the engine and looked for the source of the rattle. Sure enough, it came from the TB and not from the cylinders. But despite putting my ear near both sides a few times, I couldn't tell if it was coming from the left or right TB. I probably need a bike statoscope but don't have one and don't know where to find one over here.

Anyway, this is the symptom. The rattling only comes when the bike is warmed up and in neutral with the clutch released. So I hear it only at the lights or after a ride. When I pull in the clutch, the sound disappears. If I pull and release the clutch a couple of times, sometimes it goes away. Do that again, and it comes back, especially if I just throw the clutch out.

Can anyone tell me with some certainty that worn TB is the cause?
Bing Carburetor offers replacement parts for both sides for US$170-ish.
http://www.bingcarburetor.com/flier2.html

Has anyone tried replacing theirs?
Are there other alternatives?
Does anyone know of any step-by-step instructions with illustrations, like the one for cam replacement?

Bing says if this problem is not nicked, it can lead to TB bushing wear "which are not replaceable" so I am more than a little worried and wished to fix this ASAP. But at the same time, I do not wish to spend cash fixing the wrong problem again so hope to obtain some feedback. Thanks in advance.
myr1100r
Basic User
Posts: 19
Joined: Tue Oct 06, 2009 2:41 am
Donating Member #: 0
Location: Malaysia

Re: TB Rattling

Post by myr1100r »

I had same problem, but on the right TB only. Done top overhaul on both sides of engine, re-grind the valves, replace valve seals, and check on valve guides. After putting it back up to factory spec includes the rocker arm & valve clearance, again on left TB still have rattling noise. I suspect the noise from the engine, not the TB.

One thing obvious that I observe when I rotate the crankshaft is the chain making some noice on each complete revolution. Perhaps this might be the cause for my R1100R 95. Its like the tension of the clain released in in each complete crankshaft cycle.

What need to be done? Problem with the tensioner? Or timing of the chain of by one teeth of the sprocket?
chuzy2
Basic User
Posts: 1
Joined: Sun Feb 28, 2010 9:28 am

Re: TB Rattling

Post by chuzy2 »

I had a similar noise on my left side that I thought was perhaps excessive valve clearance. I checked all the clearances which were within tolerance. I noticed my left valve cover didn't have a rubber bumper like the right side did. I ordered a new one and installed it. It seemed to help. I have thought of doing the cam tensioner mod but haven't gotten around to it yet. I thought it could be a waste of time and money.
You might check your spark plug. A loose plug can make a rattle. If your like me you may not have a socket thin enough to fit to actually use a torque wrench on the plug.
If your not familiar with the rubber bumper you can find it in the clymer manual under engine compression test, pg 84, fig. 121.
As far as a stethescope, just use a screwdriver. Put the tip to the area you want to listen and your ear to the end of the handle. If the bike runs good I wouldn't worry too much about it.
Hope this helps.
currypuff
Basic User
Posts: 3
Joined: Thu Jan 14, 2010 12:36 pm
Donating Member #: 0
Location: Singapore

Re: TB Rattling

Post by currypuff »

Hi myr1100r,
I am planning to try my hands at value adjustment and TB balancing which so many have said will make a big difference to the way the bike runs. But like I said, I am pretty sure the sound comes from the TB in this case.
If after all the work to the valves and you still have rattling, I would think it's the cam chain tensioner. (sound from left side of engine + loose chain)
But I am no techie so will leave to more experienced forumers to comment.

Hi chuzy2,
Since my rattling happens when the bike is warmed up, and disappears as soon as I pull in the clutch cable, the cause is probably not the spark plugs. The tension of the cables shouldn't make a difference if that is the case.
I brought it to a shop and the mech said the gears are the cause. Lots of beemers have this symptom (louder than mine) and that I don't have to worry about it. Hmmm… :-k
Will try to get a second opinion. I read (ADVrider?) that if the TB shaft or bearings are worn, the rattling will stop if you press on the clutch cable pulley located behind the TB. I tried it on both the LHS and RHS and the rattling didn't go away, so it reinforces the point that the problem is not a worn TB.

The cam chain tensioner replacement certainly didn't work in my case. But it's good to have learnt how to remove and clean the LHS TB. FWIW, I now know my cam chain is not worn and that I have the "improved" part in my bike. ;)
When I have the time, I will remove the RHS TB for cleaning and check the condition of the valves. This should put the TB problem question to rest.
Using a screwdriver as an impromptu stethoscope sounds interesting. Will be testing it out.
Thanks for the replies and cheers.
myr1100r
Basic User
Posts: 19
Joined: Tue Oct 06, 2009 2:41 am
Donating Member #: 0
Location: Malaysia

Re: TB Rattling

Post by myr1100r »

Solved my problem.

Its the left TB, due to partial opening due to zero freeplay of throttle cable or sticky throttle cable (to the cable housing). Remove both left & right TB, removed the throttle cable, put some lube in the cables, for TB take out everything and do cleaning, re-assemble everything back to factory specification and walla....problem solved.
wardie
Basic User
Posts: 10
Joined: Mon Mar 22, 2010 6:23 pm
Donating Member #: 0
Location: Youngstown, Ohio

Re: TB Rattling

Post by wardie »

I would stick a carb tune on it and see if the TB's are not out of adjustment. Sync them and I think you'll find the sound either goes away or is minimal. Make sure your vales are correctly set first. Wardie
cycleman
Basic User
Posts: 4
Joined: Thu Jan 21, 2010 9:03 pm

Re: TB Rattling

Post by cycleman »

These are fairly easy to diagnos. With the bike running, put your finger on the TB wheel the throttle cable attaches to. You don't need much pressure. You'll find that you can stop the rattle easily just by touching the wheel. With the engine off, you can move the wheel back & forth a little bit.

Its this back & forth movement that sounds like a rattle or tick. No doubt this causes the wear on the shaft and eventually an air leak etc etc.

Its really too bad that BMW didn't put some felt bushings in this location like the old Honda Goldwings had on their carbed motors. It would act as a cushion & keep the shaft lubed. I would think if there was some way to duplicate the Honda set up it would go a long way to curing the rattle.
jesus80
Basic User
Posts: 16
Joined: Sat Aug 08, 2015 9:10 am

Re: TB Rattling

Post by jesus80 »

Hi, I've got the same problem (I think) on my R1150R, and I'd like to know what you guys mean by TB... throttle body perhaps?
User avatar
peels
Basic User
Posts: 1121
Joined: Wed Jun 26, 2013 11:12 am
Location: Southeast Iowa, USA.

Re: TB Rattling

Post by peels »

jesus80 wrote:Hi, I've got the same problem (I think) on my R1150R, and I'd like to know what you guys mean by TB... throttle body perhaps?

yes throttle body.

does it tick loudly when you throttle-up? it can wear out and the shaft can rattle under pressure.

check out this vid.

https://www.youtube.com/watch?v=QV9Vv01S0EU
2002 R1150R. Helmets save more lives than loud pipes.
Post Reply