124 Ducar cam cover assembly.

Bunglingtwit · Jun 26, 2017

Hi all, I've got this 06 Atomik pit bike that I scored for nothing and not running. I've since got it running as the problem turned out to be tappets over tightened causing a lack of compression which I discovered after pulling the head and bore off. The issue now is, it seems to have to much oil running through the camshaft and pouring out of the cam gear cover and not going to the rockers etc. when I reassembled the cam cover I noticed the engine bound up. After loosening the cam cover bolt it freed up again. Clearly something is missing there but I can't find any info or pictures on google. The cam gear bolted directly to the cam with three 9 mm bolts with the cam cover bolt running though that, at least that's how I remember disassembling it. Any ideas? Thanks guys.

motodevo · Jun 27, 2017

The flow of oil is how its designed, it comes up the clutch side of the barrel/head, the timing chain side is the return path. More than enough is thrown around to keep the top end lubricated. Take off the valve covers whilst its running if you want to confirm this. The top end only really needs a misting at most, you dont want puddles forming around the valve or even with new guides and seal it'll smoke like a 2 stroke.
There should be a small nib on the inside lip of the cam cover, it locates between 2 small nibs on the cam gear opening on the head. This stops the cam cover rotating. If it's not aligned on some there is a raised section on the back of the cam cover (that acts as something to deflect the oil running through the cam and off the gear) that should fit in between the cam gear and barrel, if the cover rotates the raised section can put tension on the gear/chain causing it to bind up like you have described. That would be my guess of what's going on.

Bunglingtwit · Jun 29, 2017

Hey Motodevo, thanks for getting back to me. I just had another look at position of the cover as you described but unfortunately this doesn't seem to solve the problem, in the picture you can see the wear ring on the cam gear and shiny end on the cover, on the oil disperser where the 2 have been contacting. Would it be possible that the cam hasn't seated in the head properly and isn't sitting far enough in? I guess I'll gave to take the head off again.

motodevo · Jul 2, 2017

Its only just rubbing. Did you have a gasket on that cover?
If not clean off all the old gasket with a blade and either get a new gasket or just make one out of thick gasket paper (only a few bucks from an auto store for a roll of it). That would be my guess at the problem is.
If you did have a gasket maybe pull the cover on the opposite side of the head (rectangular) and see if there is something stopping the other end of the cam fully seating. Of course make sure there is a gasket on that too as it will affect alignment of the cam.

You could take off the top cover and see if the rockers are centred on the lobes.

Worst comes to worst, its not going to do any damage if you shave/file half a mm off the raised section that makes contact with the gear.

Bunglingtwit · Jul 5, 2017

Just an update, you're right about the gasket, I used a cereal box to make my own. I put it back together and it's not leaking and running, I had my daughter out on it just the other day. I guess the gasket in tube didn't allow enough clearance. Thanks for your help.