Hi Monsters

A strange one...

After riding to work today I noticed a strange high pitched hissing noise coming from my Monster 620ie when running (stopped, in gear and when riding)

I can only relate the noise to when the key is initially turned to on and the instrument needles both move off 0. The bike I presume primes itself for starting. The bike makes a hissing noise. When started this sound now continues and at a higher pitch.

I'm assuming it may have something to do with the EFI but am hoping someone may have some wise words of knowledge or advice.

I am also hoping it's not on its way to perform some other fault that may be linked to this noise.

The bike performs ok at all rev ranges - no trouble starting or idling.

Another intermittent concern is that when the bike is pulling up a hill or in a high torque range it feels as if the clutch is slipping. The bike revs out - i drop the revs and ease it back on gradually with no problems. The bike has 28,000km's on the clock and about 10 thousand of those are mine. They have been easy kilometers with no real heavy riding i.e. minimal drop starts and easy revving. Could the clutch be on its way out? I thought there nay be a rev limiter on the bike? If there is its new to me.

Any advice on either or both of these issues would be muchly appreciated.

Nugget head

Sorry can't help.  But have you put this post on the Tech board too?  Will get wider readership there.

have you changed the oil recently? The slipper in my 620 wasn't happy with a certain non shell oil that I used (it was slipping under power). Changed the oil again and it fixed.

As for the high pitch noise, that's spooky. 

Could be your cam belts. You wouldnt notice them at riding speeds. 

Might be worth just checking the idler and tensioner bearings for the belts just to be sure!! But at such low K's I wouldnt think they'd be knackered! 

The belts were changed at 20,000k yes?? and its under 12 months since the change?? 

One other thing is that stuff can get behind the belt covers and rub on the belts, even the covers have been known to rub, worth a check. 

Not sure it's similar but worth thinking about. I had a hissing sound for a few months before my tank rusted thru at about the 45,000k mark - the sound I think was caused  caused by by all the rust/sentiment crap around the fuel pump/filter. It came and went so it doesn't quite sound like your issue.  Be pleased if it's not - tanks etc aren't cheap!

If your noise is always there, get your mechanic to have a quick listen.

Try popping open the fuel filler cap when you hear it. On the carbed bikes at least, there's a rubber nub thing under the filler cap that routes the tank vent - if it gets a little dislodged it can make a hissing noise as the air gets sucked past the rubber...

(And maybe check this quick - I've heard of an injected 900SS tanks that collapsed when the tank vent got blocked and the fuel pump happily sucked a strong enough vacuum to distort the tank and crease the metal!)

big

Thanks all,

The hissing problem has seemed to have dissapeared - still suspicious though.

I changed the belts myself a little while ago - re-tensioned after a few rides. Don't think its the belts though. Had tank respray recently and accidently left the rubber nub thing off when reassembling - will fit and see if the hissing happens again - strange one though.

Changed the oil/filter (Motul 5100 10W50) n air filter at the same time - the slipping was occuring intermittently before this though and is still occuring.

CRAIGO - what oil were you using n what did you change to???

Nugget Head

I run motel 5100 10w/50 in my 620ie found it shifts gear better than on the ducati recommended shell oil with no probs with the clutch.    My '03 620ie has a rev limiter, can't miss it when you hit it.

Doubt your oil's the prob

Hope that helps

Struba

Thanks Struba,

Now wondering if the rev limiter is a standard thing or if it is only installed on learner legal bikes?

Cheers.

No worries Nuggethead,

Can't say I know for fact but I would imagine any Duke with EFI would be equipped with a rev limiter.

Quote from: Struba on May 13, 2009, 01:16:05 AM
Can't say I know for fact but I would imagine any Duke with EFI would be equipped with a rev limiter.

Hmmm ... No redline on the tacho.  What's that magic number again?  [moto] Brrrpppp...popopop...chugchug...  Ahh, that's it.   

Quote from: Struba on May 13, 2009, 01:16:05 AM
No worries Nuggethead,

Can't say I know for fact but I would imagine any Duke with EFI would be equipped with a rev limiter.

agreed, there's one on the 1000 so I imagine it's there on all!

but remember...

there's no redline on the tacho....you shift with feel......for insurance....there's only one......Schaaaannons!!!!

Nugget, all 620's are injected, and all have a rev limiter, even learner legal ones. My 620 Sport DEFINITELY has the rev limiter ducsport

Quote from: Spider on May 13, 2009, 02:59:55 AM
agreed, there's one on the 1000 so I imagine it's there on all!

but remember...

there's no redline on the tacho....you shift with feel......for insurance....there's only one......Schaaaannons!!!!

I was waiting for it to rear it's ugly head 

Quote from: CairnsDuc on May 13, 2009, 01:31:59 PM
I was waiting for it to rear it's ugly head 

mustn't forget the sneering curl of the lip when saying it!!