Question Cam shaft/sprocket positioning

[loud_bird]

Hi all, Sorry if this a repost. I couldn't find any topics on this.

I am in the in the middle of replacing the cylinder head gasket (thanks for everyones help there too, I ended up ordering OEM rubbers as advised). I took the cam sprockets off the cam shafts. is there a way to tell the orientation when reassembling? I don't see this mentioned in my manuals.

 

[Motogiro]

Looking at an exploded view, it looks like there are 2 bolts for each cam sprocket. My guess would be that the 2 bolts clock the sprocket so that either way they are mounted the tooth position is the same. You can probably mount the sprocket 180 degrees either way. The intake and exhaust sprockets may also be interchangeable.

https://www.ronayers.com/oemparts/a/yam/500455f7f8700209bc792eec/camshaft-chain

 

[tuning-forks]

There are alignment marks that you line up with the edge of the cylinder head. I don't think those marks are on both sides of sprocket, so they need to be toward the outer ends of the camshaft.
I think that is why the manual says to 'temporarily tighten sprockets', that way, if you don't see the alignment marks, you flip the sprocket over.

 

[TownsendsFJR1300]

Page 5-10 in the Yamaha shop manual (S2), goes into detail re which cam is which.

.The sprockets are the same, cams are different. The shop manual shows the orientation (lobe direction)
when properly assembled.

Below pics expires in 7 days (so print it out)






Page 5-14 in the manual also shows exactly where your marks will be
when installed correctly..

Do you have the Yamaha manual??


.
Page

 

[loud_bird]

yes i do. how does tell me which 180 degree orientation thr sprocket mount to the cam shafts? i thought this just tells orientation for timing.

 

[TownsendsFJR1300]

There was a picture in the manual showing each cam, with the lobe orintation in that pic.

I don't remember but it'd show, say cylinder 1 Intake cam with say the lobe up...

Look over the manual again, it's there..


Dunno if this helps but here's a pic of my intake cam @TDC compression stroke, when I last
adjusted a valve. You can see certain lobe "direction" of the intake with a bread zip tie keeping it in place
while the exhaust cam was out. You can also see cylinder 4 lobe facing forward, the cam sprocket mark
even with the head surface:



.

 

[loud_bird]

ok I'll reread it again but I'm definitely not understanding atm thanks for the help. do you mean your first image when it says cam 1 intake and cam 2 exhaust is this the correct lob orientation? or perhaps i have a different yamaha manual my page 5-14 goes over checking chain guides and checking the tensioner.


would the shafts simply lay nicely vs being at tension if the cam shaft sprocket was flipped 180?

 

[TownsendsFJR1300]

Cam lobes apparently are facing 180 to each other:

Again, pic expires in 5 days:

 

[TownsendsFJR1300]

would the shafts simply lay nicely vs being at tension if the cam shaft sprocket was flipped 180?

Always have your cams, crank mark and head surface with the chain taught and all slack
at the tensioner.

With chain stretch, get the intake lined up with the head, then the exhaust, then the crank
as close as possible.. They may be off a knats hair but you'll know if your a full tooth off anywhere...

.

 

[tuning-forks]

According to the linked thread (post #10), the sprockets can only be mounted correctly (not 180 deg. out):

T

Thread 'camshaft timing question'

Mar 29, 2017

I'm a bit confused here.

After some work on the engine I'm about to install the camshafts again. The cil 1 is on TDC, the camshaft sprocket is aligned...

As I understand, on the compression stroke the lobes of the camshaft should be pointed outward.
The camshaft sprockets have markings on them for exhaust and intake respectively. They should be lined up with the headcase.

The problem is, if I line the camshaft sprockets like the manual says: marking and bolt as on the diagram, the first lobes do NOT point outward but inward.

I took a picture when disassembling and it appears...

• thewebhead
• camshaft lobes markings outward sprockets
• Replies: 12
• Forum: Garage / Mechanical Help

 

[loud_bird]

Thank you all for the help! I ended up needing a new timing chain but it's all set and purring like a kitten.