Jump to content

valve clearance cam lobe position? ?


VIFFR

Recommended Posts

Hey all. I'm in the process of doing valve clearance checks and I've come across a bit of a snag. 

 

I believe i am at tdc on the compression stroke (difficult to rotate engine to timing mark for cylinder 1) 

I'm trying to put the feeler gauge under the lobe however it seems to foul regardless of the thickness. By foul, i can get them under the lobe but not the way through to the other side.  Is this normal?  Otherwise  I'm thinking it may be possible that the cams were put in 1 tooth past where they should? ??

Photos are where the lobes sit for cylinder 1 tdc to measure intake. 0.16mm +/- 0.03

The other photo is the opposite side of the cams showing both intake and exhausted. This is the rear 2 cylinders, 1 and 3. 

 

 

IMG_20170620_171029.jpg

IMG_20170620_171059.jpg

IMG_20170620_170935.jpg

Link to comment
Share on other sites

  • Member Contributer

Personally, I don't get too hung up on the crank/cam position. So long as the cam lobe is pointing directly away from the valve bucket (i.e. up), you know you are on the base circle of the cam and can check the clearance.

 

Yes, you should be able to push the feeler right through the gap, but there should be some drag on the feeler as you do this. 

Link to comment
Share on other sites

  • Member Contributer

+1 on what Terry said.

Don't worry about marks, just point them away. 

You only nerd to get marks right when you reinstall cams, then it's very important. 

Also make sure you are spinning the crank in the right direction. 

Link to comment
Share on other sites

  • Member Contributer

I'm with these guys...

 

But I have some questions... why do you believe you're at TDC? Why is it difficult to turn the engine?

Link to comment
Share on other sites

  • Member Contributer

Here's the diagram from the manual. Not sure which head you took photos of but if that is the rear one, then you are 360 degrees off TDC for #1, based on the scribed lines on the side of the gears (at TDC #1 the mark on the exhaust cam gears should be at 12 o'clock).   

 

 

valves.png

Link to comment
Share on other sites

Ok perfect thanks for the replies. I figured something was wrong. I'm 180 degrees out by three looks of things.
Im doing this on minimal sleep with a 1 year old at home. Taking my time and stopping if i have any questions. Thankfully I've been lent a car for as long as i need.

Link to comment
Share on other sites

I'm with these guys...
 
But I have some questions... why do you believe you're at TDC? Why is it difficult to turn the engine?

I know I'm at tdc as i have a long screw driver resting on the piston and can see it rise and fall along with the use of timing marks.
Not difficult to turn the engine, but you can feel it firm up on a 180° cycle for the exhaust stroke then it gets a bit harder/firmer coming around again on the compression stroke.

That's how i was told to do it. Could be misunderstood and going by my results, i think i am!
Link to comment
Share on other sites

Personally, I don't get too hung up on the crank/cam position. So long as the cam lobe is pointing directly away from the valve bucket (i.e. up), you know you are on the base circle of the cam and can check the clearance.
 
Yes, you should be able to push the feeler right through the gap, but there should be some drag on the feeler as you do this. 


Thank you Terry. That's a big help. I only get to work on the bike from about 9pm onwards so my sleep deprived brain needed the clarification. I should be able to get them checked and adjusted and back together to ride to work on Friday. or not. Maybe Saturday. ...
Link to comment
Share on other sites

  • Member Contributer
49 minutes ago, VIFFR said:

Ok perfect thanks for the replies. I figured something was wrong. I'm 180 degrees out by three looks of things.
Im doing this on minimal sleep with a 1 year old at home. Taking my time and stopping if i have any questions. Thankfully I've been lent a car for as long as i need.
 

You need to get the kid to help as soon as they're old enough...Nappies are great for soaking up oil spills. 

 

This one's at university now, my how time flies...

rf900rs21.jpg

Link to comment
Share on other sites

  • Member Contributer
14 hours ago, Terry said:

Personally, I don't get too hung up on the crank/cam position. So long as the cam lobe is pointing directly away from the valve bucket (i.e. up), you know you are on the base circle of the cam and can check the clearance.

 

Yes, you should be able to push the feeler right through the gap, but there should be some drag on the feeler as you do this. 

That's what I did too. It might be a bit hard to see in the picture but I used a Sharpie to mark the opposing teeth for re-alignment on install.

http://www.vfrdiscussion.com/index.php?/gallery/image/68016-img-2297/

 

Link to comment
Share on other sites

  • Member Contributer

I used correction fluid for that, marked the tooth close a good reference point on the cam saddles:

IMG_1057.thumb.JPG.7184baf1e6eeecac3c91455d4a7a6f7b.JPG

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.