I noticed at the weekend that the base gasket on my 2005 320 4t is leaking through the thin section next to the cam chain tunnel - does anyone know where I can get a workshop manual for this bike, what I'm looking for is info on re-timing the cam. Or have Sherco put cam timing marks on the crank etc that are self explanatory - any info here would be helpful before I strip the engine down.

And if anyone has any figures for the head bolt torques, I'd be grateful for those too........

Edited January 14, 200818 yr by mark1161

If there is no factory information available, just pay attention to detail when you disassemble the top end. Take plenty of pictures and notes.

Locate top-dead-center (TDC) on the compression stroke and if there are no timing marks on the flywheel that make sense to you, use an electric pencil (works better than a Sharpie and won

I have not had a 4T apart, but in keeping with typical 4T logic there should be a mark on the cam gear to take note of as the crank flywheel is at TDC. Pull the bottom cover to ck for timing marks on the flywheel. You may have to rotate 360 degrees depending upon which stroke the motor is on, as there is a 2/1 relationship between cam and crank gears!

The chain could have marked links which will probably line up with the cam after a few revs.

Just note the relationship going in, and put things back the same! NO varience!

Edited January 16, 200818 yr by copemech

No marks or owt, TDC cam lobes need to be pointing down with lobes at about twenty past and twenty too if looking at a clock face.

Cam won't fit through hole in this position, so you have to twist and locate cam in place, then install cam sprocket and chain.

Make sure cam chain tensioner is removed before you do any head work, and it should be the last thing you install after you get it all back in place.

I've sorted the oil leak - so thanks for all your help, and now a confession...........

It appears that I managed to nip the crankcase breather pipe between the petrol tank and the radiator cap which pressurised the crankcases and caused this leak, the good news was that it almost disappeared after I re-routed the breather - there was still the slightest weep, so I cleaned it with brake cleaner and sealed along the face with some silicon

THIS WORKED !!!!!!!! so the head is staying on until this 'bodge' finally gives up the ghost - but it's had 6 hours use since I did this and it's holding out, so fingers crossed)

It's definitely worth keeping an eye on where this pipe is before fixing the tank down..... lesson learned

Sweet... thanks for the follow up, It may save someone else some heartache down the road.