Dave Barrett
Registered user
I know there's been several threads about various engine noises in the past, but I'm currently "in discussion" with my local dealer about a particular noise that they claim "they all do".
It's best described as a knock, and can be either irregular (during warm-up) or regular (at idle when hot). It's most likely one of the three chains, although the left-hand chain tensioner has already been replaced, the original supposedly faulty.
The noise is most obvious under the following conditions:
Fast idle lever engaged, engine start. The usual one second knock as the oil pressure build up in the chain tensioners, then a (relatively) quiet fast idle for 15 - 20 seconds. After this time, a very loud irregular knock is heard, literally as if someone is banging a large hammer from the inside of the engine. If the idle speed is dropped to normal, the noise disappears.
Once the engine is warm, the noise disappears. Under normal operation, it can be detected, until the engine is really hot (after 50km or so), then the noise can be lightly heard at idle speed. It's now more regular, definitely quieter, but still present.
As mentioned above, the dealer reckons all twin spark boxers do this. My old single-spark GS didn't, my twin-spark 1150RS didn't and my current engine was OK until about 3000 km (currently 11,000km). I was on a run with some other BM owners over the weekend , and mine appeared to be the only one with this noise, although the last time mine was in the workshop, a loan 1150 Rockster also suffered (but not as bad) from the same concern.
So, the question is, am I being paranoid, or is it true that most 1150 twin-spark Boxers have this noise?
It's best described as a knock, and can be either irregular (during warm-up) or regular (at idle when hot). It's most likely one of the three chains, although the left-hand chain tensioner has already been replaced, the original supposedly faulty.
The noise is most obvious under the following conditions:
Fast idle lever engaged, engine start. The usual one second knock as the oil pressure build up in the chain tensioners, then a (relatively) quiet fast idle for 15 - 20 seconds. After this time, a very loud irregular knock is heard, literally as if someone is banging a large hammer from the inside of the engine. If the idle speed is dropped to normal, the noise disappears.
Once the engine is warm, the noise disappears. Under normal operation, it can be detected, until the engine is really hot (after 50km or so), then the noise can be lightly heard at idle speed. It's now more regular, definitely quieter, but still present.
As mentioned above, the dealer reckons all twin spark boxers do this. My old single-spark GS didn't, my twin-spark 1150RS didn't and my current engine was OK until about 3000 km (currently 11,000km). I was on a run with some other BM owners over the weekend , and mine appeared to be the only one with this noise, although the last time mine was in the workshop, a loan 1150 Rockster also suffered (but not as bad) from the same concern.
So, the question is, am I being paranoid, or is it true that most 1150 twin-spark Boxers have this noise?
