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Hi, have picked up a nice A5 with 120,000km which has been parked up for 6 years. Checking engine out and have dropped the oil pan off - bit of a mission to get it off so suspect it hasn't been off before. Looked ok for the mileage and screen pretty clean but some plastic gremlins in the bottom of the pan. It has a manual cam chain tensioner fitted but looks fully adjusted. Have taken cam cover off and cam chain idler is still there although very worn with end of one tooth missing. Will be taking head off but wondered if anyone has ideas on where the plastic bits might have come from (6x20 screw wasn't in the oil pan, just there for scale). Wondering if it might be a stuffed roller on the bottom of the tensioner but thought they were black.

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I suspect you're looking at the remnants from a broken water pump drive bevel gear  It's located in the bottom of the cylinder block on the back side. You should be able to see it once the head is off. 

MCG water pump drive bevel gear  . Is a German site and I can't link you to the specific page but you can find the bevel gear replacement service under the water pump tab. These are great people to deal with and the only ones that I know of that offer this service.

 
 



The cam chain tensioner roller is a nitrile roller (rubber) and is black.

The tensioner toothed sprocket is nylon and there is a replacement sprocket made of steel and can be had from   Liska cam chain idler sprocket
 

Kawboy, thanks for getting back. Head is off but water pump bevel gear looks fine. Turned it over and no broken or lost teeth. Certainly in better shape than the cam chain idler gear. Bit of a mystery.

I do have another A5 I have owned since new, bought in Australia, original and unmolested. The frame of the A5 I'm working on is a bit different. It has a niffty handle that folds out in front of the left rear shock and sure makes getting her on the centre stand a lot easier - I thought these were only on the Voyager frames? Also has the small tube on lower frame that an accessory security cable could be put in and I know this feature was on the US models for GPz550 and GPz1100 in the early 80's. Pretty sure this A5 was sold new in NZ but could be a US spec?

The "Search" tab on this site can be invaluable. I did a search this morning for  "nylon" and changed the search time from "within a year" to "any date" and found this from Oct 2013. Thank you Strate6

(Cut and Paste)

Full Top End Overhaul Z1300
Mike,
The 1300 has a collection of Nylon Gears inside including.

Water Pump Drive.
Cam Chain Idler Gear.
Ignition Pick Ups
Oil Pump Drive Gear.
...........& probably one or two more I cannot think of now !

The Camchain Idler Gear is the one that wears out quickest & is situated inside the center of the cylinder head (which needs to be removed to reach it)& has the camchain running over it. It can be seen by removing the cam cover & using a torch.

The Water Pump Drive Gear is once again in the middle of the cylinder head & off-set just behind the Ignition Pick up unit. It can also be seen by removing the cam cover but is hidden a little more. This gear should last 60k miles plus if the oil levels are kept high & changed frequently. It only fails if the engine gets too hot & it becomes soft...........normally caused by low oil level.

The other gears cannot be seen so easily as inside the motor, but very rarely if ever need replacing as they are well covered in oil most of the time.

Look after your bike & its oil carefully & you should not have to worry!

Pete

Your pics resemble teeth of some kind. If you saved them maybe try to puzzle them together and see what they may form???
On the other hand, they also appear to be flat?? suggesting maybe a spacer/ washer??
I'd be making the determination before just writing it off and carrying on.

KB
 

Ok, this has been driving me crazy. Water pump drive looks fine, cam chain idler worn but no big bits missing, not sure about ignition pick ups??, pretty sure the oil pump drive gear is metal. I have spent hours pouring over the parts book looking for possible nylon bits. The pieces didn't seem to have any common mating surfaces. Took some closeup photos and blew those up. Seems to have been a circular 'ring' about 9mm deep, 2mm thick at thick edge. Then did more searching of the forum and found jimichu's post of some 6 years ago [worn cam chain idle gear, must change? HELP] - the photo on page 4 maybe my answer.
My bike has 120,000km on it and has had several previous owners. It is probably unlikely that the current cam chain idler gear is the original. What if a previous idler gear had worn as much as (or even more than) jimichu's and then the thin side flanges the cam chain had formed as it chewed through the gear, broke off, descending to the sump, to be found much later.