Engine rattle above 6000rpm on acceleration.

[Narcotics]

Hey guys I'm wondering if someone could point me in the right direction. I've read a lot of the engine noise posts and haven't come across this one yet.

So I'm just going to describe and give the information as best I can.
engine has done 80,000kms
Engine rattles at 6000rpm or above while accelerating and gets louder/ faster with rpm up to 10000 but Stops / mostly stops when cruising at high rpm.
If you just ride it around at 5000rpm you wouldn't know anything was wrong.
Doesn't make the noise in neutral at the same RPMs
Has not lost any power just makes horrible noise.


I removed all of the fairing to make sure it wasn't that rattling again.

[Bluesmudge]

If you have confirmed that its not the fairings, then its probably a loose engine mounting bolts.

[herennow]

exhaust headers on tight?

[mr72]

Mine does that a bit, it's the rubber bushing on the front edge of the tank that's degraded. I just need to replace it. But instead I ignore it.

Of course, a "rattle" could also be detonation, maybe you have an ignition timing issue or a hot spot on a valve. It could also be a "knock" since it happens mostly under more load and not cruise, which would indicate a much worse kind of issue. IOW, "rattle" may mean different things. I'd want to chase all that down before I assumed it was benign.

There was one day I freaked out about a rattle like this that happened like at 5K-7K rpm on my GS, I thought it was going to grenade itself. Turned out the nut holding the horn on was loose.

[Narcotics]

Doesn't seem to be those parts rattling.

I forgot to mention in my first post that it doesn't make the noise in neutral revving it to the same rpms.

[The Buddha]

Whoa, that's almost a first.
Describe it more - metallic ? Likely not, you removed plastic - was it a plasticky rattle ?
BTW load related rattle could be detonation - so you're on kinda thin ice here - try a premium and maybe even an octane booster on top of that.
Cool.
Buddha.

[Narcotics]

So I thought I'd start with the cheapest part of detonation issues and start with new spark plugs, I also sprayed some carby cleaner up the leads.

While doing this I noticed a bolt missing from the right side oil cooler hose bracket. I shoved the cardboard from one of the plugs in there and took her for a spin.

Case closed. Bolt fell out of bracket making a metal to metal vibration.

and thanks to all.

[user11235813]

You sprayed carb cleaner up the high tension leads?!, that doesn't sound very good. Maybe contact cleaner and a bit of electric grease, but isn't carb cleaner bad for rubber and plastics?

[Narcotics]

I thought is was bad for everything. There is rubber in the carburettor if I'm correct?

[mr72]

Yes it's bad for rubber parts, including the spark plug wires. And including the o-rings and especially the rubber diaphragm in your carbs. So yeah, you shouldn't spray it on anything that might have rubber parts in it, including the carb. It's fine for cleaning the carb once you have fully disassembled it and removed all the rubber and plastic parts.

Contact cleaner would have been OK in the plug boots but it's also not really intended to use on rubber. Difference here is plug boots and wires are typically not natural rubber, latex, viton, etc., like o-rings or the carb diaphragms, but rather they tend to be silicone based and may not be impacted by the contact cleaner as badly as natural rubber. Probably didn't hurt anything, but probably didn't help it either. Carb cleaner won't clean corrosion from the plug connector, it'll just deposit a solvent on there and potentially degrade the insulator. Then it evaporates.

[The Buddha]

The few seconds it sat there before evaporating wont hurt much of anything except paint.
I'd really not want to soak carbs in it, but you didn't do nothing. You can even spray it on rubber in the carb, just don't do it for
hours together. One spritz wont even hurt that.

Yea lost bolts make a racket. Lesson learned.

Cool.
Buddha.