stevedo
Registered user
Hi peeps, I have a relatively new to me 2004 R1150RS twin spark that's running a bit rough. Vibration is quite bad, particularly under load, and there's a "knocking" noise under load which disappears if I feather the throttle off slightly. Vibration increase quite significantly as revs rise although the bike does seem to rev quite freely. There's also a knocking at idle. Bike fires up well from cold and will hold a high idle speed (2,000rpm) on the "choke" and will idle reasonably well until warmed up.
The noise at idle sounds just like this video posted by Chris harris on YouTube https://www.youtube.com/watch?v=j_vm7C5buVU
The video is of a bad stick coil diagnosis. However, the failed stick coil shows no spark when tested.
Here's what I've done so far.
1. Replaced the rubber caps for the vacuum intakes. The old ones were non-original and I'm not convinced they were working properly.
2. Balanced the throttle bodies and checked correct seating of cables.
3. Checked valve clearances, all OK.
4. Checked for spark. Purchased new spark plugs, pulled secondary plug caps and with original plugs in place put new plugs in plug caps and ran bike to check for spark. Did this one at a time and for stick coils as well. Spark is present at each plug but does not appear to be particularly strong although I have no term of reference. e.g. at one stick coil spark is only seen to one "side" of the plug. This is different to what was seen in the video of a bike with a bad stick coil where there is no spark at all. Do/can stick coils partially fail or break down or is it an all or nothing?
5. Replaced old plugs with new.
Bike runs no differently than before.
From research I think it may now be one of two things:
1. Stick coils
2. Fuel pipe/s in fuel tank, maybe the u shaped one.
From the symptoms, what does the collective think my issue could be? Stick coils are expensive, anyone in the Southampton area about who may be willing to let me try their known good stick coils? I'd rather not pay that much money and not solve the problem.
Many thanks
Steve
PS bike has done 39,500 miles
PPS I've previously owned an R1100RS for 14 years and know that the current running of my bike is not normal.
The noise at idle sounds just like this video posted by Chris harris on YouTube https://www.youtube.com/watch?v=j_vm7C5buVU
The video is of a bad stick coil diagnosis. However, the failed stick coil shows no spark when tested.
Here's what I've done so far.
1. Replaced the rubber caps for the vacuum intakes. The old ones were non-original and I'm not convinced they were working properly.
2. Balanced the throttle bodies and checked correct seating of cables.
3. Checked valve clearances, all OK.
4. Checked for spark. Purchased new spark plugs, pulled secondary plug caps and with original plugs in place put new plugs in plug caps and ran bike to check for spark. Did this one at a time and for stick coils as well. Spark is present at each plug but does not appear to be particularly strong although I have no term of reference. e.g. at one stick coil spark is only seen to one "side" of the plug. This is different to what was seen in the video of a bike with a bad stick coil where there is no spark at all. Do/can stick coils partially fail or break down or is it an all or nothing?
5. Replaced old plugs with new.
Bike runs no differently than before.
From research I think it may now be one of two things:
1. Stick coils
2. Fuel pipe/s in fuel tank, maybe the u shaped one.
From the symptoms, what does the collective think my issue could be? Stick coils are expensive, anyone in the Southampton area about who may be willing to let me try their known good stick coils? I'd rather not pay that much money and not solve the problem.
Many thanks
Steve
PS bike has done 39,500 miles
PPS I've previously owned an R1100RS for 14 years and know that the current running of my bike is not normal.

