Cam Chain

S

steam

New member
Sorry to ask this as I searched the forum and saw lots of cam chain questions, however...

I have a noise when opening the throttle quickly sometimes - it sounds a bit like a slack primary chain, a kind of slapping noise (so I will be checking this first). If its not this, could it be the cam chain?

Can the cam chain be adjusted without opening up the top of the engine please on a 1978 1200 mirage

Thanks for your replies
 
steam said:
Can the cam chain be adjusted without opening up the top of the engine please on a 1978 1200 mirage
Click to expand...

No.

The cam cover needs to be lifted to ascertain correct tension, applies to all Lav triples.  Requires years of experience to do it otherwise..... :D

While you're in there, check condition of the tensioner blade!

piet
 
As peit says check that blade it sounds maybe you never have (or previous owner) they can wear through and half drops through into the crank case,this means you have worn through metal and there are now tiny bits floating around in your oil,lets hope not,let us know what you find
 
The front cam chain guides can break also (aged ones are quite brittle) especially if not positioned properly on assembly.
 
Hi "Steam",
I know forums are a great place for info,  especially this one, but if you are having to ask something like that may I suggest you get hold of a handbook or the Green Book and have a look through..seriously, you will then see the basics of cam and primary chain adjustment. And in that connection, I speak as one who recently had to deal with a broken cam chain tensioner....only discovered after, exactly as described above, it mysteriously snapped and floated into the gearbox preventing selection of first(but no other) gear.
Nick7
 
There are so many noises in the Laverda engine sometimes it can play tricks on your ears.
Recently I was convinced I had a crank rattle and it turned out to be a slack primary chain. The sound seemed initially to come from the front of the motor.

If your noise is happening when you quickly open the throttle are you sure it is not pinking/pre-ignition? That can sound very metallic to the ear.It would tend to fit with when it is heard, on opening the throttle. As said previously a slack chain is usually on the over-run when the load is taken off it.
Just my 0.02.
 
ok then, premature ignition of the the combustible fuel mixture in the cylinder,pinking sounds better (or not if the piston holes)
neale
 
Thanks for the replies

I have read the green book end to end - it is useful, but there is nothing like the experiance of a real user when it comes to troubleshooting

My engine was completely rebuilt a 450 miles ago, it could still be a broken cam chain tensioner blade and I will check, however I will check the primary chain first, does the adjustment with the engine running when warm really work?  Thats a new one on me!

I wondered about pinking - thats just what is sounds like. The carbs are way out and need setting up - it over fuels a lot as well. Good flames out of the exhaust, but not too good for the engine I feel.

I will post a reply when I have it sorted, I guess a new set of plugs and a tune up can't hurt?

 
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