Rattling Noise On Idle - 550 Primary Chain HI-VO

Update: I bought two clutch baskets off ebay, and my suspicions were correct... Those bushings are supposed to be that way. It's not a crack, it's a slot put in there on purpose by the manufacturer.

So, not being able to leave well enough alone, and since I now have a plethora of 550 clutch baskets, I took one of them apart. I pressed the bushings out for a better look:







So, I'm not sure what I'm going to do at this point. All indications are that I've been chasing a non-problem this whole time, and I should simply get over it. Only reason I've invested any time in it to date is that (since I've owned this bike since new) I know that it did not used to sound that noisy. If it weren't for that, I'd be able to write it off easily.

I think I'm going to put it back together with my original basket and get back to square one. In any event, I don't think anything is in grave danger of catastrophically failing, so maybe I'll mess with end play in the off season.

Crap. I hate mysteries.

 

Ya think? Actually, only sorta. Just chased it up the wrong tree, and because it's so small you couldn't see it.

-Be sure you use the tightest-fitting bushing when reassembling, why not?

-Stick to 20W-whatever oil unless you're actually riding when it's below 41 out.

-GET your valves in spec. You know they're overdue.

Think about this:

The engine itself (carbs and ignition aside) is a big air pump. A four cylinder air compressor "running backwards" (powering instead of being powered) but a big 4-cylinder air pump nonetheless.

The VALVES control the air flowing into and out of this air pump. Over time, as those valves slowly go out of spec, and the duration and timing of their opening and closing changes, they will change the smoothness of the air pump. As the engine runs relatively less smoothly than before, EVEN THOUGH YOU DON'T NOTICE IT, it's going to affect how much "rattling" goes on in the primary transmission.

If you put the valves back in spec, and consequently re-sync the carbs, that air pump will do its job more smoothly than it was, WHETHER YOU NOTICE IT OR NOT. But I guarantee the clutch and trans will rattle less.