Hi guys
I've had my AN400K8 since December and hav'nt been out on it much due to the weather etc, but this morning was beautiful land as I live in Northumberland I thought I would have a ride around the borders into Scotland and back.
Well the ride was fantastic next to no wind and bright sunshine.
However I noticed that on acceleration the burger sounded very raspy, as though there was a exhaust leak where the silencer fits on to the exhaust pipe, so I stopped, took off my helmet an revved the engine it sounded perfectly normal
My question is I suppose what should the engine sound like while your riding under acceleration, does it normally sound raspy or have I an exhaust leak that only appears under load.

May have a loose joint or hairline crack in the exhaust if it is doing it under acceleration. When under load the engine can move, the gap can open up slightly and that could give you the 'rasp' that you hear. It won't do it so much if you just rev it without being under load. Just a guess.

Yeh I wondered about that, just thought it might be some acoustic effect when riding it so thought it best to get feedback before delving in with the scanners.

Mine is pretty quiet all the time.

Have you tried holding a rag over the exhaust and see if that makes it blow anywhere?

Also, the end caps can work loose and resonate at speed so that is worth a look. Beware! 3 of the set screws on the dummy end cap are dummies and there is another end cap under the decorative one

Bluebottle wrote:Mine is pretty quiet all the time.

Have you tried holding a rag over the exhaust and see if that makes it blow anywhere?

Also, the end caps can work loose and resonate at speed so that is worth a look. Beware! 3 of the set screws on the dummy end cap are dummies and there is another end cap under the decorative one

Was about to try the rag over the end trick, but didn't know about the dummy end cap so will check that out as well.
Just wanted to get some feedback as to what the engine should sound like when riding, as it's the first single I've had.

Miseryguts, welcome to the Burgy club! Some good advice here, but in my experience it will be the exhaust downpipe gasket. That's the one between the front downpipe coming down from the cylinder head, and the silencer pipe that slides onto it. There is a tubular/cylindrical gasket in that joint that compresses slightly as the silencer clamp is torqued (torque is just 23nm). If it's too loose, or conversly, overtorqued, it leaks under load. Or the gasket may have been reused too many times and it's burned away in key areas. Often if thats the problem, it sounds ok at tickover and when revved with no load. The gasket can be used a couple of times without detriment but should be renewed every third time to be sure. They cost about £10 from a Suzi dealer. Of course, many people overtighten the silencer joint bolt to downpipe and this distorts the pipe. If thats the case you may need to take some minor remedial action to get a good seal with a new gasket fitted. Easy job though.

Ooh, good point Data (as always)

I think they were more like £15 from my local dealer though ( I could be wrong but I seem to remember thinking 'kin ell I'll get another use out of this one instead but I'm kidding myself really)

Please post if you or anybody finds a cheap source

My 2010 400 as always sounded a bit harsh on acceleration it doesn't have any leaks
and as not changed over 17000 miles taking the snorkel out of the air filter seems
to help but it's still there and I think normal.

Thanks guys
Will certainly check the gasket between the silencer and the down pipe.
There seems to be a flange type joint about 6" from the silencer sleeve joint towards the front this looks clean with no carbon deposits around it.
I was kind of hoping to get a collective opinion as to what the normal engine sounds like on a single under acceleration just in case what I am hearing is normal.
Don't know if certain helmets filter out different frequencies to leave a rather harsh sound.

Yes, I guess we all hear things a bit different anyway, Then with the helmet thing, this makes a further difference. My 2012 model does not sound harsh under heavy acceleration. But, when my front downpipe gasket needed replacing after using it for a third time, it's leaked slightly and did sound harsh. The only sign it was leaking was this change in the sound the bike made under load. There was no carbon deposit as they leak from the pipe slots each side of the tube. The pressure is so great it just keeps the slots clear and the gases are very clean anyway.

Bluebottle, my last genuine Suzi exhaust gasket was £9.98 from my Suzi dealer. That was about a year ago though. Just to be sure...it's the one on the end of the downpipe I'm talking about, not the one up at the cylinder head end. I'll check to see what the going rate is next week as I'm about to do a big service on mine and I want all the genuine parts. I'm also going to get special Suzuki wind from the factory for my tyres too!