VFR 800Fi knock noise

myvision · Scooby Slapper Joined: 26 May 2016 Karma :

What do we think this noise could be?
I've 200 miles to get home on friday I'm not sure I'll make it!
I can't remember hearing this noise before I worked on the exhaust.

YouTube link here,

https://youtu.be/FGlNZ57MYww

New engine time?
Fresh oil and filter 700 miles ago.
New air filter 15 miles before this noise.
Still pulls hard and has no side effects to performance and it drinks petrol same as it always has.

Is it fucked or can I save it?
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VFR800FI, YZF600R Thundercat and FZS 1000

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Doesn't sound terminal. Wise man say, if you have to strain to hear it, it's probably not a disaster.

It could be one of two things in my estimation:

1.) One of your downpipes has a pinhole from rust (they do look pretty rusty). Or maybe one of the header gaskets is blowing?

2.) Apparently the VFR's can make a 'knock' when the throttle bodies need balancing. Because one cylinder's fuelling is a bit off, it causes some sort of resonance through the crank etc as I understand it.

Either way, I doubt it's terminal, and if you hadn't have said there was a knock before watching the video I'd have assumed it was normal for that bike. Mine is quieter but I have a standard exhaust which is fairly rust free.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

Sounds like an exhaust leak to me. And you were working on the exhaust.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

myvision · Scooby Slapper Joined: 26 May 2016 Karma :

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

myvision · Scooby Slapper Joined: 26 May 2016 Karma :

It was the copper seal on the front right cylinder.

https://i.ibb.co/kBpQZsp/20200606-152901.jpg
https://i.ibb.co/0fCy0kT/20200606-152600.jpg

Put a new one in and good as new.
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VFR800FI, YZF600R Thundercat and FZS 1000

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

ThunderGuts · World Chat Champion Joined: 13 Nov 2018 Karma :

ThatDippyTwat · World Chat Champion Joined: 07 Aug 2016 Karma :

Front ones are more of an arse, they're probably siezed. Rear may be a faff, but I'd rather deal with a bit of faff than fucking around with a fucked stud.
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'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)