Does the CB1100 motor become smoother over time?

[GoldOxide_imp]

I've owned a couple of bikes that required removal of the rear mufflers to remove the rear wheel (or at least removing them made the wheel removal easier.) I'm thinking of my 2003 Triumph Bonneville, specifically.

First time I replaced the mufflers, I tightened everything to spec, and immediately encountered a lot of vibes. So, upon the advice of an old timer (older than me??) I loosened slightly (key word is slightly) the muffler mounts and clamps, rode the bike around the block several times up and down through the rev range, then re-tightened everything I'd loosened. I think this procedure allowed the pipes to find their natural resting position, instead of being in a slight bind.

This cured the vibe issue, apparently coming from the engine through the pipes, into the frame, then to me. This also happened when I replaced one of the exhaust headers and mufflers (one piece) on my 2000 W650. This is purely anecdotal. What I'm suggesting is ...... you're probably feeling engine vibes, but there may be several reasons they're being transmitted to the frame and then to you.

Some of the first BMW K bikes experienced excessive vibes, that could be partially cured with a pair of shims. This was a case of the rear engine frame mounts being slightly spread perhaps 1/8" further apart, due to irregularities in the frames from bike to bike. In this case, the frame wasn't a 'cradle' like ours, but one where the engine was a stressed member. Some of the vibes were being caused due to the frame being under tension when the right and left mounts were fully tightened. A pair of shims removed this tension. However, the vibe issue on these bikes wasn't totally eliminated until the arrival of the K1200, with full frame and rubber-mounted engine. The flopped over four (Flying Brick) wasn't counterbalanced.

Food for thought. Hope you find the problem. BTW, the K100/K1100 did get smoother with miles

Bob

(+1) Agreed. Over-tightening grommet-based support bolts can be an issue when two components are brought into contact, or very close contact.

[mattmcuomo@yahoo.com]

I've owned a couple of bikes that required removal of the rear mufflers to remove the rear wheel (or at least removing them made the wheel removal easier.) I'm thinking of my 2003 Triumph Bonneville, specifically.

First time I replaced the mufflers, I tightened everything to spec, and immediately encountered a lot of vibes. So, upon the advice of an old timer (older than me??) I loosened slightly (key word is slightly) the muffler mounts and clamps, rode the bike around the block several times up and down through the rev range, then re-tightened everything I'd loosened. I think this procedure allowed the pipes to find their natural resting position, instead of being in a slight bind.

This cured the vibe issue, apparently coming from the engine through the pipes, into the frame, then to me. This also happened when I replaced one of the exhaust headers and mufflers (one piece) on my 2000 W650. This is purely anecdotal. What I'm suggesting is ...... you're probably feeling engine vibes, but there may be several reasons they're being transmitted to the frame and then to you.

Some of the first BMW K bikes experienced excessive vibes, that could be partially cured with a pair of shims. This was a case of the rear engine frame mounts being slightly spread perhaps 1/8" further apart, due to irregularities in the frames from bike to bike. In this case, the frame wasn't a 'cradle' like ours, but one where the engine was a stressed member. Some of the vibes were being caused due to the frame being under tension when the right and left mounts were fully tightened. A pair of shims removed this tension. However, the vibe issue on these bikes wasn't totally eliminated until the arrival of the K1200, with full frame and rubber-mounted engine. The flopped over four (Flying Brick) wasn't counterbalanced.

Food for thought. Hope you find the problem. BTW, the K100/K1100 did get smoother with miles

Bob

(+1) Agreed. Over-tightening grommet-based support bolts can be an issue when two components are brought into contact, or very close contact.

(+1) Agreed. Over-tightening grommet-based support bolts can be an issue when two components are brought into contact, or very close contact.

Definitely, the first time I removed and replaced the engine in my Vulcan Classic I over tightened the motor mounts, vibrated like crazy. Torqued them to specs and it was all good.


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