Cam Sprocket mismatch

[Zig's GS]

In my efforts to get the GS850 running smoother, I discovered something that I am sure is not right! When on TDC, the notches on the right end of the cams don't face each other (not in 1 line) The intake differs with about 30degrees. Retarded. The phasing of the 2 cams is correct. (20 links) The inlet cam sprocket carries a marking - 451, but the exhaust has a marking 490 and so does the 2 spare cams I have. Is this normal? By judging with the eye, it looks as though the cam notches would line up if I change the sprocket.
Also.... according to my Haynes manual, there should be a idler sprocket between the intake and exhaust cams, not so on my bike. GS850GX.
Also... the Haynes manual tells you to measure the lenght of the timing chain and it should not exceed 157.ish mm, measured between 1 and 20 link.....and then it shows a picture of a vernier between pin 1 and 21!!!

[Nessism]

My guess is that someone left out the idler which is messing up the timing of the intake cam. Shouldn't be too hard to source one but you will have to remove the cam chain tensioner to install it.

[bwringer]

Uhhhh... yeah, that idler is NOT optional and it is needed on EVERY GS850 model.

Man, just when I thought I'd heard of everything...

[Zig's GS]

What baffles me is the fact that there is no provision made for any sort of tensioner between the cams. There is a piece of frictionliner inside the camcover on the inside???

[tkent02]

Pictures, please.

[SqDancerLynn1]

Could they have replaced the head with a GS1000 one ? without the gear!!!

[TeamDar]

Could be a GS1000 shaft drive motor in a GS850 frame?

[Zig's GS]

Could be a GS1000 shaft drive motor in a GS850 frame?

Engine Number says it's 850, barrels says 840something.
It could be a gs1000 head. I have spare cams from a 1000 and the marking also says 490.
Will take photos tonight.

maybe that's why the breather cover on the cambox was not the same as the 1 I ordered. Will a 1000 head fit on the 850 barrels??

[Zig's GS]

Some photos for the detectives out there

[SqDancerLynn1]

Yes as far as I know the 1000 head will fit on the 850. The cam chain has the same # of links, Their may be a difference in the cam sprockets

[nufnuf]

just looked at my aussie gs1000 st which is apart, 451 inlet 490 exhaust

[Zig's GS]

Ok, that did not work. Will try again

what am I doing wrong. I uploaded the photos but they are not here?

[Zig's GS]

just looked at my aussie gs1000 st which is apart, 451 inlet 490 exhaust

If you look at the cams in the head with the timing set to TDC, are the notches facing each other right on??

[tkent02]

Ok, that did not work. Will try again

what am I doing wrong. I uploaded the photos but they are not here?

Easiest to upload them to photobucket or something similar, then put them up here.

[Zig's GS]

Again.....