Help Needed With Timing Alignment Marks
 

OK so i have rotated the engine so the timing marks are aligned in the window on the LHS - spot on.

Look at the all the timing marks for the camshafts and they are all spot on too and the mark on the driveshaft aligns on the with the crankcase mark as well.

So everything is definitely correctly aligned, so all good. I take pictures of both horizontal and vertical cylinders (to help later if required) and fit the camshaft holding tool i have to the vertical cylinder.

Off with the timing belts and definitely nothing moves.

Packing up for the evening and for some reason i look in the window on the LHS and the timing marks are no longer aligned.

I definitely had everything aligned spot on and didn't move anything so my question is - What's happened??

Cheers
Simon

The only thing I would say is to take them off and do it again.

I had some issues with the timing belts on my 748 as it wasn't obvious if the alignment marks were correct or not ... they seemed to be slightly one way or the other based on a single tooth difference. I took it all off, reset everything and put them back on until I was happy it was right. It was the first time I'd done it so wasn't 100% sure!

It went round Brands without going bang so it must have been ok ;)

I spoke to Neil at Cornerspeed earlier and he assured me that all was ok and that i shouldn't worry about the mark in the window and that the mark on the driveshaft can actually be a couple of mm of the mark on the crankcase.

Also looked at my pics and counted the number of teeth on the belts between the timing marks and i can check that against my new ones when i refit.

Cheers
Simon

Simon
If the marker in the Window has moved then so will have the marker on the lower pulley that aligns with the marker on the crankcase
I never take much notice of the mark in the window when fitting the felts on to the pulleys providing all the pulley markings line up

As Kev said. :)

Yeah the marker on the pulley was a tad out of alignment with the crankcase, nowhere near enough to put it one tooth out though. This must have moved a bit when i released the tension on the belts as i definitely didnt move the back wheel.

Cheers
Simon

As the other end of the layshaft is geared directly to the crank I wouldn't have thought releasing the belt tension would turn the crank, but maybe it can if the locking tool is inserted before releasing the tension.

I always insert the locking tool after I've removed the belts so releasing the belt tension is more likely to move the cams

Thats what i did, so maybe it was the cause :confused:

I'm happy now though that all is well and i'm going to get it all replaced correctly :)

cheers
Simon