Cam Timing issue? - Triumph675.Net Forums
Reply
 
Thread Tools Display Modes
post #1 of 11 Old 11-24-12, 18:13 Thread Starter
Polystigma
Member
 
Polystigma's Avatar
 
Join Date: Oct 2010
Location: Los Angeles, CA
Posts: 563
Thanks: 2
Thanked 2 Times in 2 Posts
Cam Timing issue?

I have opened my bike up today for a valve check and possible adjustment.

The, Haynes manual states that at TDC, all cam lobes for cylinder 1 will be pointing up away from the bucket.
This is just not the case. I have the dot and hash mark lined up on the crank.
Both cams have the lines facing inward, and flush with the head.

Basically everything indicates perfect sequence.... except for the cam lobes.

At TDC the only lobes facing up are Intake on cylinder 2, and Exhaust on Cylinder 3.

What may the problem be? Or does one even exist?

Polystigma is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 11-24-12, 18:29
Travisty
Junior Member
 
Travisty's Avatar
 
Join Date: Sep 2009
Location: Mad Town, WI
Posts: 147
Thanks: 1
Thanked 0 Times in 0 Posts
Send a message via MSN to Travisty
This may come across like I'm being a smartass, but not the case.
You engine is mounted at an angle, at TDC the lobe will be at an angle. Try rotating the motor again til your marks line up again.
Consider a triumph manual in the future.

Slow is smooth, and smooth is fast
Travisty is offline  
post #3 of 11 Old 11-24-12, 18:33 Thread Starter
Polystigma
Member
Threadstarter Threadstarter
 
Polystigma's Avatar
 
Join Date: Oct 2010
Location: Los Angeles, CA
Posts: 563
Thanks: 2
Thanked 2 Times in 2 Posts
I have both manuals. Seems like the Haynes may not be 100% accurate.

Polystigma is offline  
post #4 of 11 Old 11-25-12, 00:22
MacBandit
Senior Member
 
MacBandit's Avatar
 
Join Date: Sep 2008
Location: Seattle
Posts: 10,381
Thanks: 2
Thanked 153 Times in 138 Posts
Garage
There's never been a Haynes manual that was even 75% correct and Haynes is the best of the aftermarket manuals.

If all the lobes were lined up you would have big issues.
MacBandit is offline  
post #5 of 11 Old 11-25-12, 01:08 Thread Starter
Polystigma
Member
Threadstarter Threadstarter
 
Polystigma's Avatar
 
Join Date: Oct 2010
Location: Los Angeles, CA
Posts: 563
Thanks: 2
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by MacBandit View Post

If all the lobes were lined up you would have big issues.
I realized that after some long analysis. Thanks for the response though.
The timing is perfect.

Now my next issue appears to be getting a correct reading from a feeler gauge. The angle really throws off my feel, especially on the exhaust side. Be it precurved gauge or straight. And I only have a couple sizes in precurved.


Last edited by Polystigma; 11-25-12 at 01:14.
Polystigma is offline  
post #6 of 11 Old 11-25-12, 01:38
MacBandit
Senior Member
 
MacBandit's Avatar
 
Join Date: Sep 2008
Location: Seattle
Posts: 10,381
Thanks: 2
Thanked 153 Times in 138 Posts
Garage
These aren't screw type rockers your adjusting. It's shim and bucket the feeler gauge goes or it doesn't. Don't force it. Throw some lube on the gauge if it feels like its rough. Remember you just need the valves in the range the exact point in that range isn't really important.
MacBandit is offline  
post #7 of 11 Old 11-25-12, 11:49
Travisty
Junior Member
 
Travisty's Avatar
 
Join Date: Sep 2009
Location: Mad Town, WI
Posts: 147
Thanks: 1
Thanked 0 Times in 0 Posts
Send a message via MSN to Travisty
I've bent my gauges in a half hexagon shape to make it easier to read.

Slow is smooth, and smooth is fast
Travisty is offline  
post #8 of 11 Old 11-25-12, 16:29 Thread Starter
Polystigma
Member
Threadstarter Threadstarter
 
Polystigma's Avatar
 
Join Date: Oct 2010
Location: Los Angeles, CA
Posts: 563
Thanks: 2
Thanked 2 Times in 2 Posts
Bummer, my exhaust valves seem to all be way out of spec. Engine has 12K miles on it.

I believe to have done good measurements. By feel, I went with what produced a smooth "stutter". If pulling back and forth produced a coarse "stutter", I called it too tight.

Cylinder and cam lobe orientation from left to right, when in normal riding position.

Measurements...

Cylinder 1
Exhaust
Left .279mm Right .229mm
Intake
Left .152mm Right .178mm


Cylinder 2
Exhaust
Left .229mm Right .220mm
Intake
Left .152mm Right .178mm


Cylinder 3
Exhaust
Left .229mm Right .203mm
Intake
Left .178mm Right .178mm


What gives?


Last edited by Polystigma; 11-25-12 at 16:54.
Polystigma is offline  
post #9 of 11 Old 11-25-12, 20:19
Travisty
Junior Member
 
Travisty's Avatar
 
Join Date: Sep 2009
Location: Mad Town, WI
Posts: 147
Thanks: 1
Thanked 0 Times in 0 Posts
Send a message via MSN to Travisty
I've done 12k's where they were all out. Not abnormal.

Slow is smooth, and smooth is fast
Travisty is offline  
post #10 of 11 Old 11-25-12, 22:49
MacBandit
Senior Member
 
MacBandit's Avatar
 
Join Date: Sep 2008
Location: Seattle
Posts: 10,381
Thanks: 2
Thanked 153 Times in 138 Posts
Garage
Definitely. The first time you adjust them doesn't mean much. If they change a lot between adjustments then something might be up.
MacBandit is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Triumph675.Net Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode


Forum Jump

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome