Ugly ticking sound from engine, 2013 Tiger 800 XC

[Londonglide]

Originally Posted by Rauno_N

Hi all,

Little update. Since the fault was not found, i chose the way of buying another second hand engine and finally got to ride a couple of months end of last season.
Exhaust remained old one so all the possible crack doubts in exhaust were eliminated.

I have still not given up and took the engine completely apart again. It was no surprise that main bearings, big end bearings, pistons, connecting rods, crankshaft is fine. Also completely disassembled the cylinder head this time, valves, springs, valve split cotters all fine.

Yesterday came to mind a question relating to balancer shaft drive gear. Why is it designed with 2 separate gear wheels that are side to side each other ?
I can imagine purpose is to keep the balancer drive gear and crankshaft gear wheel tightly together ? Wondering if there could be a broken spring between the 2 balancer gear wheels.

P.S double click on the picture enlarges it

Many years ago, I used to service CNC equipment, and the measuring systems used the system as a backlash eliminator, so no discrepancy was measured when axis direction changed. I have seen it in many engines and systems over the years.
Its actually called a backlash gear in the service manual.
There is another on the clutch basket, I think

[Tenequip]

I’m amazed with your efforts to find your problem. The only suggestion I can add is a little trick, I learned on the farm, as a kid. On the farm if a piece of equipment was making a noise, we would take a  piece rubber hose and put to our ear and go over the equipment. This trick would normally local the problem or at least the general area of the problem. Those pieces of aluminum look like part of the problem.
Good luck with your search!

[Paulhere]

Those bits of ally & also the ticking could be broken piston ring lands, have you checked the pistons?

[diggerled]

I listened to the tone and rhythm in the video. It sounds very familiar to me. I would replace the cam chain tensioner with a manual tensioner that is available. Seems the OEM is not holding or getting oil pressure. The spring load inside the tensioner is enough to make it appear that tension is good. With no oil pressure to boost its strength, the intake cam "bucks" back slightly once every revolution. Or half engine RPM.

[Rauno_N]

Thank you for all the opinions. Pistons have been checked thoroughly, aluminium particles from the sump still have to be from the previous clutch drum break (sump was not removed after replacing the clutch drum).
Absolutely no other engine part has damage to connect with these particles.

Regarding cam chain tensioner, both manual tensioner and new OEM one have been tested, no changes.

Now the balancer backlash spring could be the potential issue. First i noticed the backlash gear stays practically aligned with the balancer main gear wheel after removing the balancer shaft from the engine. While googling the balancer shaft pictures pop up where these two are not aligned and manual also describes a very specific procedure how to align the gears before mounting the shaft in it's place.
In my case, i can easily do it without even the special tooling, because the spring pressure is really low.
Backlash gear spring seems to have severe wear on the contact surfaces, unless this is the normal shape of it ? Hollow/concave ?




Same wear also visible on backlash gear :



Only thing not letting me sleep is that this finding has to be a result of a long time wear and most likely could not happen with the fall, that started all this trouble.

Some pictures of cylinder linings, pistons, connecting rods, all looking good.