Grandvista noise

[packfan]

I have a 3 year old GV and I ride it all year round, this winter as I was coming home it starting making a noise that sounds metalic. I took it in to the dealer and he believes that I am loosing the crankshaft bearing. I had synthetic oil in it and always change the oil at 5000 mile. Was wondering if anyone eles that has a GV has ever experienced this or heard of it?

[jprestonian]

Every 5000 miles?

I think the recommended oil change interval for the GV is every 2000 km, which is about 1200 miles.
.

[olbull]

Yes 1200 miles..There  isnt  a filter  to  romove  contaminants.... Almost  makes using  synthetic a waste...Viscosty  wont break  down  in  that  shorter  duration... As  the  man  used  to  say  "pay me  now  or  pay  me  later"..Im  sure  there  are  few  old  farts  on  this  board  that  remember  that  commercial

[drifter]

my gv had 38,000kms (23,750 miles) when i sold it, rode it very hard. had 2 trips 21hrs and 15 hrs straight but never had any problem with the engine. changed oil every 1,000km and gear oil every 2,000km.

[Rudolf]

I also hear a clinking noise from the engine only at idle, but when running the engine at higher revs the noise seems to disappear. Here is a clip about it:

Can anyone explain me what makes this noise?

[Rudolf]

here is a video with my scooter making a klinking sound even with the variator removed. I believe the freewheel of the starter may have come loose or the bell of the alternator is loose. Correct me if i'm wrong.

[Rudolf]

I didn't see any play in the bearings of the crankshaft.

[windwheeler]

It is called "piston slap".  Scooter engines have usually more play piston to cylinder, and when it is cold it can make this noise. I bet when you get it really warm/hot it doesn't do it.  Mine does it too i idle, cold.

 As long as your G/V performs correctly (starts well) and has good power, don't worry to much, unless it aggravates you so much that you want to do a piston/cylinder overhaul.

[Rudolf]

The noise is present even when the engine is warm, and it's coming from the right hand side of the engine, i suspect the starter system has some play or something there went loose...

[windwheeler]

Ever found out what the noise was?

[Rudolf]

Not yet, i'm waiting for winter to come so i can start the maintenance. As long as the weather permits to ride i'm not gonna start the maintenance because this bike is my only motorized vehicle.

[Rudolf]

Ever found out what the noise was?

Today on the 27th of December 2012 I've dismantled the whole engine and i've found out that there isn't any problem with the starting system rattling, the problem is elsewhere: I've found out that the cam chain was stretched beyond the cam chain tensioner's limit or maybe the chain is a different size.... The chain has a lot of slack and it wobbled at low rpm and at higher rpm didn't wobble alot. The chain also ground down a little bit from the aluminium casing. There is also some horizontal play in the axle connecting the oil pump with the water pump.

[windwheeler]

How many miles or km are right now on your engine?

[Rudolf]

29760 Km, manufactured in 2001. I'm it's second owner, imported from an old man in Italy.

[Rudolf]

Here is an image showing where the timing/cam chain was hitting. I have about 0.5mm of free play in every link of the chain.