| Author | Message | ||
     Reepicheep |
The Uly is making kind of an odd sound, almost like a resonant rattle of a heat shield, at around 2500 RPM, mostly notably under no load deceleration. No runability problems, no smoking, no over heating, no other issues with the bike. Does not seem to be trending any worse. I took apart the primary cover and checked everything, no problem in there. I checked the exhaust flapper, the sound doesn't change regardless of position (though that isn't totally conclusive). I've checked all the isolators and engine mounts I can get at, no problems there. I checked various other flexy points (flyscreen cover, dash parts, etc) and cant make the noise stop by pushing on those either. I also dropped the oil pump and looked up at the pinion gear, still in perfect shape and no scary glitter came out of the cam cavity. This bike is a repaired salvage title, and did a stoppie into the side of a corolla hard enough to shear the rear head mount (that bolts to the frame) completely through. So the bike has taken quite a wallop in the past. The rattle does seem to come and go with temperature and time, but not really conclusively by any recognizable pattern. It's just kind of moody. Used oil analysis does show my Uly is chewing on those weak 07 crank bearings, there is a lot of silver in the oil. When I replaced the rear head, I did a quick inspection of the crank and that rod and saw no play of any kind. And it seems to be that a crank noise would get worse under load and RPM, not better. I know that having done reasonable diligence, I should just ignore the rattle and keep riding the bike until it gets better or worse. But it kind of bugs me, and I do have a full gasket set for that front cylinder already laying on the shelf. And I don't mind too much working on the engine, and at 30k miles replacing the valve guides and seals and decarboning the head wouldn't bother me anyway. So my next suspicion is maybe collapsed lifter, maybe bent pushrod? So what's actually involved in replacing lifters? I've been in the top end, I've had the cams and pinion gear out, but I don't recall ever actually removing a lifter. Do you pull the cam cover (which means removing at least one rocker box cover first), then pull the cams, then drop the lifters out from the bottom? Also, when you replace a lifter, do you also have to replace cams (as they wear into each other)? If I'm looking at $300 in cams instead of $30 in lifters, well, then I can ***totally*** live with the tap and wait to see if it gets worse.  | ||
| Akbuell |
Don't think the cams need to be replaced, unless the lifter has caused excess wear to the cam. Usually caused by a lifter whose rollers have died, causing the lifter to 'skid' over the cam and wearing a groove in the cam surface. As to removing the lifters, it is a bit more complicated than on my X-1. The XB manual has step 1 as cleaning the area around the base of the pushrod covers. Step 2 is remove heads, so the pushrod covers can be removed. Then remove the anti-rotation pins, and pull the lifters up. Hope this helps, Dave | ||
| Reepicheep |
That does, thanks Dave. | ||
| Bluzm2 |
Bill, it could be a lifter is dirty. Try running a can of Seafoam in the crank oil. Dump in a can, run it for a short while then change the oil. I've heard SF quiet down the noisiest lifters in a matter of a minute or so. It's worth a shot and will cost you a can of SF.. | ||
| Reepicheep |
Good idea Brad, I'll try it. What's weird about it is that it comes and goes half randomly, and occasionally it literally sounds like a pebble in a blender, not just the resonant rattle like a loose heat shield, but like something is literally bouncing around. |
