Cam Alignment Tolerance

[Mashermoto]

Ok Ladies and Gentlemen...today's lesson is how to pay attention when installing the cam sprockets


Here is the intake cam alignment at the T mark.


Here is the exhaust cam alignment at the T mark. Better I would say

So, your probably asking what was giving 'ol Masher so much grief aren't you Well here it is


This is a shot of the intake cam sprocket. The problem was with the exhaust cam sprocket, but I can show you the deal from this picture.

I had the exhaust cam sprocket installed backwards. You see the raised landing behind the sprocket bolt. That side was on the other side. I also noticed that one sprocket hole has that little round mark at the top. The bottom holes don't have one. So I suspect that raised marking is there to tell you to use those holes when making the alignment.

So the mystery is solved. Now that the cam sprockets are installed with the correct face outward, and the raised bolt hole marks on top when the alignment holes are in line with the mark on the caps, and the ignition timing is at the T mark...life is good again Now I can get some sleep

Thanks for all the comments

[Ivan]

Very interesting..... now my brain is lurching into gear with grinding noises and lots of smoke.

[petejw]

Good to hear you got it all sorted out.

[Steptoe]

O.k

You just successfully put the wind up me , enough to go & check mine, [am dealing with a small vibration].

All my marks line up spot on,but here's the thing, both my sprockets are on the same way, with the small raised mould on the bottom holes.

So maybe as long as both sprockets are on the same way, they line up, the next thing to make me nervous is do I muck around changing the sprockets "just to see" or leave sleeping dogs lie?

[petejw]

Steptoe,
are you saying that ur sprockets are 180 degrees out,
that wont make any difference as long as you have them facing
the correct way.

[petejw]

This has been an interesting thread,
and if you read back, theres some experienced people
who thought you had it right at the beginning. Goes to show
how careful we need to be with regards to lining these cams
up correctly.

[Steptoe]

180 is right

hey Pete, now that you say it like that, moving them will be pointless wouldn't it? being that they are both the same

[petejw]

Yep, no point in it.

[Mashermoto]

Steptoe,

There is a reason to check to see if the sprockets are facing the right way. If you notice from the pictures, the surface of one side is raised around the bolt holes. The surface of other side of the sprocket is completely flat. The flat side is the one that mates against the cam shaft. If both sprockets were backwards, the teeth would be spaced a little off center with the teeth on the crankshaft and the bridge that fits between the two sprockets. I don't know if that little bit of spacing would cause damage, but it certainly isn't the way Yamaha engineers designed it to work

If your sprockets are facing the right way, and the alignment is correct, then you should sleep well at night

[Mashermoto]

Steptoe,

I just re-read your post. I don't know if the little nipple at the top of one set of bolt holes matters or not. It looked to me like they served a purpose, but I don't have a reference to the OEM installation.

I would think you are OK if the alignment is correct and the sprockets are facing the right way.

Sorry about that, should have read more carefully...and isn't that what Pete just said

[tarzan]

Hey Mashermoto,
What year and model is you're bike?
I am working on a 78E and don't see those raised bosses on the cam gears.
I am having timing mark alignment issues like you had, and noticed you're gears were on backwards.I didn't remove mine, but maybe the PO did?
I was wondering if maybe the early model cams don't have the bosses.
So I guess I'll have to remove the gears just to check.My gears look like they are flush to the flange on the cams, so I doubt mine have the bosses.

[Lamric]

There were no early or late model cam sprockets they are the same for all models of XS1100s (and the intake and exhaust sprockets are both the same part). It's part number 1L9-12176-00-00.

[Mashermoto]

Tarzan,

Lamric has it right. My bike is a 78E. The picutres below are from a 81. The sprockets are identical.



This shot shows the bolt side. Notice the nipple at the top of the sprocket bolt hole? That indicates which side goes where.



This is the back side. The sprocket should fit flush against the mounting surface.

Hope that helps.

[tarzan]

Thanks guys,
The sprockets were on backwards.I flipped them around.Now the dots all line up.
I spent a couple evenings and half today trying to figure the problem out.
Rick

[Mashermoto]

Well...there you go...another satisified customer