SV Portal Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
Problem with camshaft. Dowel pin is rotated.

This pic shows the dowel pin pushing on the exhaust bucket of the rear cylinder. It causes the exhaust valve shim clearance to be .018" on this valve. It's a bit hard to see but it is just to the left of the cam.

Automotive tire Motor vehicle Rim Gas Automotive exterior

Since I really struggle attaching more than one image I will do another post in a minute
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #2 ·
Here is the camshaft rotated to show the cause of the problem

Motor vehicle Gas Rim Auto part Automotive design

Surely that pin should have the flat either down against the machined flat on the shaft, or up so that it clears the bucket. My question is, which one?
I was unable to find this info in the manual (although I'm sure it is there somewhere).

Any help would be appreciated.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #3 ·
OK, so you can tell this is my first time with the valves!
I found that the dowel rotates as part of a mechanism. Still, it jams up solid against the bucket and has no clearance. Is it supposed to be like that?
 

·
KNEE DRAGGER
Joined
·
5,140 Posts
OK, so you can tell this is my first time with the valves!

I found that the dowel rotates as part of a mechanism. Still, it jams up solid against the bucket and has no clearance. Is it supposed to be like that?


Yes it is supposed to contact the bucket. This is the decompressor unit to get the engine to start easier. The centrifugal forces the cause the weight to move once started, this then rotates the pin so it will no longer contact the bucket.

-ms
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #5 ·
Thanks for the explanation.

So would it be correct to say that you cannot use the "cam tip pointing directly away from bucket" method to measure clearance on this particular valve, and that you will get an artificially high reading if you do?

I am concerned about that now, because I already did the front cylinder this way, without realizing there might be a decompressor to possibly skew the measurement. Is there a decompressor mechanism on the front cylinder too?

Edit: Pretty sure the answer is yes to both. Looks like I'll be going back and doing the cam positioning using the TDC method. By the book. Fancy that.
 

·
KNEE DRAGGER
Joined
·
5,140 Posts
Thanks for the explanation.

So would it be correct to say that you cannot use the "cam tip pointing directly away from bucket" method to measure clearance on this particular valve, and that you will get an artificially high reading if you do?

I am concerned about that now, because I already did the front cylinder this way, without realizing there might be a decompressor to possibly skew the measurement. Is there a decompressor mechanism on the front cylinder too?

Edit: Pretty sure the answer is yes to both. Looks like I'll be going back and doing the cam positioning using the TDC method. By the book. Fancy that.


Please follow the method as described in the service manual. It lays out proper cam positions to make the measurements.

Basically you measure each cylinder at TDC on the compression stroke. This assures you don’t have the problems you describe.

-ms
 

·
Disturbed, very...
2003 SV1000S
Joined
·
1,551 Posts
You could do what i did.... i removed the decomp gear many years ago.....no probs and it got rid of a horrible chattering noise.....
 

·
Registered
Joined
·
90 Posts
You could do what i did.... i removed the decomp gear many years ago.....no probs and it got rid of a horrible chattering noise.....
Only reason for you to remove it was to avoid that noise? Would the noise be audible at whole RPM range?
I thought it was just the scissor gear make some noise and whine because they are straight cut tooth.
 

·
Disturbed, very...
2003 SV1000S
Joined
·
1,551 Posts
Yeah it was that long ago i cant remember what the noise sounded like now...ha ha.... i know it also effects the decomp assist, which to be honest i dont think it made much difference.
I just remember it was quieter......
If i ever have to use my spare engine, i wont worry about it.....i think the crank end float will be more annoying anyway....it has more float than my original engine i think.....
 
  • Like
Reactions: estevns
1 - 9 of 9 Posts
Top