Cam wear or not? What to do next?

I've installed one of beetle's maps on my GRiSO. I was advised by beetle to re-set the tappets to the spec that the map was written for. I had not looked at the valve clearances on my GRiSO until now as I only bought bike in September last year, not ridden it over Winter and as it has 6,000 miles on the clock with full main dealer service, so didn't consider it necessary.
Surprisingly for me, I found that the inlet tappets on the off side were set at 0.020" The other inlets were set at 0.006" IIRC and both exhausts at 0.010". beetle says that the A5 motor is normally set at 0.004" / 0.006" respectively, so none of the settings were at standard settings.

Obviously I am now wondering if the cam is wearing or whether some buffoon did a rush job and set the clearances incorrectly? I will be checking the clearances in a couple of hundred miles or so and beetle kindly sent me some info that Pete Roper has previously posted on pre-terminal camshaft wear signs.

The bike has I believe, a full service history and was bought by me from a main dealer. I have only covered just over 1,300 miles on this bike as I have two other bikes to run as well as a car.

So what to do? If I contacted the supplying main dealer and told them that I have found this anomaly and adjusted the tappets to 6 and 8 thou, do you think that they are likely to use this information to shift some blame to me as it is of course possible that I am also a buffoon as well (even though I'm not). Or is it advisable to keep quiet for now, run it and monitor the situation and see what happens, and then if necessary act?

How many kms on the bike in total?

Pete

The bikes got 7,000 miles / 11,200 kms on it give or take a few.

it could be, but is early.

I'm sure I said 6 & 8 thou?

If your clearances are the same after a few hundred miles, it'd be safe to assume whomever set them at the dealer is a complete pillock.

Had a similar thought this weekend when i was adjusting the valves on my G12. While everything else was pretty close to spec, I found BOTH exhaust valve clearances on the left cylinder had opened up to 0.55mm.

Question(s):

1. While this tells me something is wearing out, upstream of the valve, would this fall within "normal" parameters? In which case i will ride a few more miles and monitor noise & clearances. Mileage is currently at 18,500mi.

2. Is it possible to remove top half of cam block without disengaging the chain for a quick inspection of the lifters? If so, the tank wouldn't even have to come off, which would very much suit this lazy twat.

As usual,
Thanks!

No, if your valve. Lea ranges have opened up to half a mm stop riding immediately!

No, to inspect you have to remove the cambox and remove the weir from the bottom.

DO not stert your bike until it's fixed.

Pete

Pete Roper wrote:

No, if your valve. Lea ranges have opened up to half a mm stop riding immediately!

No, to inspect you have to remove the cambox and remove the weir from the bottom.

DO not stert your bike until it's fixed.

Pete

Thanks, Pete.

Dammit! I'll pull the cambox and see what's down there. Does it tell you anything that BOTH exhaust valves were out by the same amount?

Jin

Not worth risking. It could just be it was serviced by a shaved ape but the risk isn't worth it.

When I do Mark and My bikes' swaps I'll do a photo essay on it but I can give a run down if needed. Hardest thing is releasing the tension on the left hand cam chain.

Pete

Pete Roper wrote:

Not worth risking. It could just be it was serviced by a shaved ape but the risk isn't worth it.

When I do Mark and My bikes' swaps I'll do a photo essay on it but I can give a run down if needed. Hardest thing is releasing the tension on the left hand cam chain.

Pete

Pete:

Would be most grateful, when you have time, if you could post a narrative of the most efficient way to "cheat" this procedure with engine-in-bike. There are plenty of pictures available in the Workshop Manual and "8V Training Course" for background.

As you mentioned, the thing that makes me nervous is disengaging timing chain and preserve timing w/o reference to an open timing case, where one can see the gears and line up the marks. My priority is the Left cylinder as on sits on the bike.

Fucking amateurs, eh!?

Thanks Again,
Jin

No need to open the timing chest. Perfectly easy to do in the frame. Don't even have to take the tank off to do the left side but you do for the right.

Basically you set the engine up at TDC compression on the left hand side and then after removing the small dome headed 4mm Allen screw in the back of the LH cylinder, you slide, carefully, a flat bladed screwdriver down between the chain and the tensioner blade and slowly lever it back to bleed down the tensioner plunger. When it's pushed back far enough you can insert a prong of some sort, (I use a 2.5mm Allen key.) through the hole the 4mm Allen bolt came out of and it will slip through a hole in the tensioner blade and into a divot in the cylinder casting to hold the tension off the chain.

You then undo the 10mm bolt in the end of the camshaft that holds on the oil flinger and sprocket, (Use a socket and ratchet on the crank nut and another one on the cam bolt and work against each other.) once the flinger ring and bolt are off wriggle the sprocket off the cam and cable tie it to the head through the breather plate hole.

Next you loosen the two 8mm bolts at the back of the camchain tunnel before finally undoing the four 15mm stud nuts that retain the rocker gear and cambox. From there you just lift the cambox and rockers off. Don't loose the dowels!

Flip it upside down on the bench, (A surprising amount of oil will come out so have some rags handy!) and undo the four 6mm Allen bolts that retain the cam oil bath and weir and lift it off. Note it is pegged with tiny pins so be careful! Once that is off you can lift out the cam and its shim if fitted and the tappets will be revealed.

Pete

well if they had both sides play, you can first start with right, if thats ok, you could leave left.
But you still need to take the tank off.

The thing with the left side is as pete writes, and remember some workshops ruined the tensioner while doing it. And with mine I suppose they glued the small 4mm screw so I almost turned it round inside and was having bad thoughts about how to get it out.

One side at a time, don't start turning the crank while one if off. You seem to want to keep it simple...

beetle wrote; I'm sure I said 6 & 8 thou?

You did, but quoted the A5 settings which my engine is, and then advised to go 6 / 8 thou as that is what the map was built with ....which I did

"Normally the A5 specs are 4 & 6 thou, but as I have an A8 (which the map was built with), the valves are set at 6 & 8."

Pete / Pauldaytona:

Thanks! I could understand Pete's little essay on the first reading... that's encouraging.

Much appreciate the hand-holding. Going for it soon.

Having the pdf that guzzi made for the cam change is good.

pauldaytona wrote:

Having the pdf that guzzi made for the cam change is good.

Paul:

I have not seen this one. Can you post it to Library here, please.

Thanks!
Jin

done, I see you should do it in three hours to qualify

pauldaytona wrote:

done, I see you should do it in three hours to qualify

Paul:

Hah! more like 9 hours for this monkey...
That cam replacement guide by Moto Guzzi NA is brilliant.

Thank You. Thank You.
Jin