View Full Version : not good noises
Well, seeing as the snow has gone now and i can go places on the bike again, i rode to a meeting this afternoon.
The noise is worse.
I've had the fairing off the bike, tried it with restrictors out, checked all bolts i can see that may be loose etc - All with no joy.
I took my bike on Saturday to Veloce as Tantrum992 had suggested and they couldnt shed any light on the noise coming from my bike without being able to take it apart.
They did narrow it down to the rear cylinder tho.
The noise seems to have gotten a lot louder and is getting louder the more i ride.
So I guess its time to start taking things apart here.
It's just very bizarre what is actually rattling, as it isnt there all the time. It's very sporadic. The only constant is on decelleration and sustained revs in certain rev ranges.
I'm fightened cos its loud and sounds expensive, but have this gut feeling it will be something stupid.
I know this is kinda a long shot, but any suggestions of things to look for that may be loose or rattling?
Thanks
Cy
If it's coming from the cylinders then it's almost certainly piston slap. The 600 has very short piston skirts, so short I asked four seperate mechanics what the bloody noise was before letting it go and just sodding riding the thing!
On the downside it did expire into a ball of flame at brands hatch about six months later:o :lol: I have a feeling that was more to do with being revved to 110% for every second of the race though!
Cheers,
Ali
hrm flames arent ever good hahaha
Im guessing that aside from replacing/upgrading the pistons there is nothing i can do to prevent piston slap?
Theres no fuel additives or anything i can use to help reduce it?
long shot i know...
Cheers
Cy
Check that the nut holding the cam pulley on hasn't come loose. Unlikely, but it can happen and happened to me once. Easy to check - just whip off the belt covers.
Originally posted by Fiver
Im guessing that aside from replacing/upgrading the pistons there is nothing i can do to prevent piston slap?
Cy
Even replacing the pistons won't do a thing. Mine slapped like a drunk sumo with brand new pistons in. The skirts will be the same length regardless.
The best option by far is to get a cheap 900 engine and bung that in. :devil::devil::devil:
Well im about to tear it apart to investigate.
I just rode to town, and it stalled twice enroute at junctions, with a sudden "click" as it stalled both times.
It is also sounding like a bag of nails when you rev it in any kinda heavy handed way.
Time to investigate.
*grumble*
Cy
Found it!
The top pulley on the front cylinder is wobbly as hell.
philthy
03-Mar-2006, 17:26
Veloce were only one cylinder out then:lol::lol:
http://scoot.net/gallery/bbs/wheel.mov
I noticed that the camshaft it sits on can turn by about 1mm, is this just down to the valves needing adjusting? or cos the belt is slacker cos of the wheel being on the skew?
The camshaft itself isnt loose, so im presuming its the wheel or woodruff key that is knackered, it just worries me what damage has been done inside to the valves.
No wonder it souded like a bag of nails when it was running.
Also, im not bad with spanners, but is this something i can do myself? or should i put it in to the shop to do?
Im *really* not flush enough at the moment to be paying out £40 odd quid an hour at the moment for repairs.
Thanks
Cy
Ah, I was right. It happened on my front cylinder too, and made a hell of a racket. At least it is the front - you don't need to drop the engine. It's not too difficult a job to strip down the head, but you might need a new cam shaft, depending on how chewed up the end is. If your luck's in it'll be just a new woodruff key. But you'll deffo have to replace the pulley nut - they're single use only, and need a special tool to loosen and torque up. I got a bloke to make one for me. Or you could just take the head to your dealer and ask the mechanic to loosen/tighten them for the price of a pint. The valve gear's probably ok.
You live, I learn. Good luck getting it sorted. I still maintain that they sound like a bag of spanners, even when they're running well! :lol:
bugger.
Well that will be the camshaft shagged then wont it?
http://cyspace.co.uk/pics/ouch.jpg
This bill is going to be expensive. joy.
Cy
monstermob 998
04-Mar-2006, 12:58
found this -- this morning!!!!!!!
http://img117.imageshack.us/img117/8158/pulleyandkey1pt.jpg (http://imageshack.us)
looks like we similar problem Cy:puzzled:
Must be catching huh?
That sucks Dave.
Hopefully yours is just the key that is smeared and no more. How's the keyway?
Im worried mine may be more than even the camshaft as i can turn it a little less than 1/4 of a turn, so maybe the valve stems may be bent too. yikes.
Then, hopefully the piston isnt damaged......
I have this gut feeling that when the guy fitted the restrictor kit he may have dropped something into the cylinder by accident and never said.
Now if only my cylinder head would come off so i can check....lots of stuck bolts and no blow torch.
The irony is that i bought this bike to be a reliable daily rider... i spose i should laugh.
Snap!
http://cyspace.co.uk/pics/snap.jpg
hehe.
Also....
http://cyspace.co.uk/pics/barrel.jpg
and...
http://cyspace.co.uk/pics/head.jpg
Luckily its not bent.
Originally posted by Fiver
and...
Luckily its not bent.
unfortunately, it will be bent, not a lot maybe, but it will start to wear the guides giving you higher oil consumption.
It also wont be seating perfectly, so you'll get blowby under power, and lean-mixture banging and spluttering if you shut the throttle at higher revs.
Check the seating by making sure the valve is shut and pouring a little petrol in the head - you dont want any leaks into the inlet tract at all.
It looks like the pulley allowed the cam to move rather a lot.
Just checked it and it seals pretty good. no leaks
I see what you mean tho. It has been spluttering pretty badly and popping on decelleration..
Also the plug read as mega lean
Is it worth spending the £40 on a new valve or should i look for a used one?
What could cause all of this to happen? just wear and tear?
Originally posted by Fiver
Just checked it and it seals pretty good. no leaks
I see what you mean tho. It has been spluttering pretty badly and popping on decelleration..
Also the plug read as mega lean
Is it worth spending the £40 on a new valve or should i look for a used one?
What could cause all of this to happen? just wear and tear?
Desmo cams accelerate and decelerate the valve without help from a spring, so all the forces are transmitted to the cam drive, and if the nut is not doen up properly, it will allow a tiny bit of movement, which, when you ride, er, enthusiastically, as you have to on a 600, causes a tiny hammering effect, which can only get worse.
A good mechanic will notice this movement when they change the belts, but if corners have been cut, the movement will get worse faster.
Originally posted by Fiver
Just checked it and it seals pretty good. no leaks
I see what you mean tho. It has been spluttering pretty badly and popping on decelleration..
Also the plug read as mega lean
Is it worth spending the £40 on a new valve or should i look for a used one?
What could cause all of this to happen? just wear and tear?
oh - re spluttering and lean plug readings - the std airscrew settings are way too lean, you need to screw them out 3 turns from fully in and you will get better idling with less low rpm popping.
Originally posted by phil_h
Desmo cams accelerate and decelerate the valve without help from a spring, so all the forces are transmitted to the cam drive, and if the nut is not doen up properly, it will allow a tiny bit of movement, which, when you ride, er, enthusiastically, as you have to on a 600, causes a tiny hammering effect, which can only get worse.
A good mechanic will notice this movement when they change the belts, but if corners have been cut, the movement will get worse faster.
Thanks for that. i understand it a lot better now.
Its actually nice to have the head off to get a better idea of exactly what happens when it runs - im used to dealing with 2 stroke systems and less moving parts..
Odd thing.. the nut was tight. It was quite tough to get off today.
Although i got 5 years of service history with the bike, i have found (stupid) things where corners have been cut so anything is possible.
The belts were replaced back in september 05 as were some head internals (but im not sure which head).
Thanks again (to all) for being patient and answering all my Q's.
Cy
monstermob 998
04-Mar-2006, 21:37
unfortunately mine is on the horizontal so its engine out for me- wierd thing is i never noticed any extra rattles or bangs i was just giving it a clean-the cam doesnt look as bad yours cy but i would feel happier with a new one that isnt worn- i have got spare bottom end. barrels and pistons but no spare heads:barfy: belts were done 4000 miles ago-i'll have to wait until next week before i get chance to get the head off to investigate further
That is crazy, Dave !
Still cant beleive the same thing happened to you. It's complete ****bag you have to drop the engine. I guess im lucky in that sense that it was the front cylinder on mine.
The more i think about it, youre right, i will probably have to bite the bullet and go for a new cam.
I saw a spare head with internals on ebay about 3 or 4 weeks ago that didnt sell and was up for £50... kicking myself now for not snagging it for spares.
Really not looking forwards to paying over 200 rubs for a camshaft.
One good outcome is that i have learned a TON today. :lol:
Cy
monstermob 998
05-Mar-2006, 07:48
cy
its a bit of a wierd coincidence isnt it- i maybe caught mine before too much damage was done although the woodruff key isnt a snug fit in the cam - i'll get a new one and see what the fit is like before i go stripping the whole lot out
i was thinking of maybe taking cams to an engineer shop and seeing if it was possible to get the key way and pulley slot machined wider and fit a wider woodruff key- i.e to take out the wear-- maybe one of the more technical afficiniado's on the board maybe be able to advise-- either that or get the lot welded together:D
there are race cams, Ergal pulleys and off set keys available from Ducati Performance but they probably cost an arm and both legs- i dont think they give any more power just smooth out the torque thru out the rev range
then there are some adjustable pulleys available from http://www.veetwo.net/index.asp
i like they're hexagonal pulley nuts! better than the slotted thing as standard
Martini
05-Mar-2006, 19:46
You two got me worried, so when I had my 600 to bits today for a pre-season clean I checked my pulleys. Fortunately both are fine.
Monstermob- I have had problems with loose woodruff keys in the past (many, many years ago on a car alternator) and had an engineering company repair the damage (as I recall they filled the old slot with weld and re-machined it). However, given the very hard nature of the camshaft material and the accuracy required I'm not sure that this is an option for you. Your idea of machining a larger keyway may work, though.
If 750 cams and pulleys are the same, I have a couple of spare complete 750 heads in the garage...........
Paul
monstermob 998
06-Mar-2006, 23:46
mmmm believe it or not - according to ducati workshop manual the cams on the 600 and 750 have the same lift and duration but obviously the valves are bigger diameter--havent had time to fully investigate any further damage i:e valve guides and valves
my machinist mate says the keyway can be widened without too much bother but suggests using vernier pulleys to get the valve timing spot on
Originally posted by monstermob 998
mmmm believe it or not - according to ducati workshop manual the cams on the 600 and 750 have the same lift and duration but obviously the valves are bigger diameter--havent had time to fully investigate any further damage i:e valve guides and valves
my machinist mate says the keyway can be widened without too much bother but suggests using vernier pulleys to get the valve timing spot on
But how much do you want to spend :D
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