CB350 Valve clearance adjustment

[Curbcast]

I just set my point gap & timing.


Now attempting to adjust my valves.


Im pretty clueless to it all. The fact that Im super proud I set my timing right (made the little bulb indictor too) sums up my knowledge of zee motors


When you open up riders left valve tappet covers all you see is.... The valve rocker arm & valve spring retainer


As I spin the rotor counterclockwise the rocker arm & spring retainer go UP and DOWN.


From what I understand, the manual is telling me that when the whole assembly (rocker arm/spring retainer...etc) is all the way DOWN, the piston is at TDC?


Lets start with that I geuss. Riding season is here but I gotta figure this out.


Thanks tons!

 

[Sonreir]

No... there should be marks on your alternator that indicate top dead center for each piston. Something like LT and RT?

 

[HerrDeacon]

Curb, do you have a manual? It will explain it better than I can write up here. Its a pretty straightforward process but you need to get the crank at the right spot for each side. If you need a manual you should be able to find one here: http://www.hondatwins.net/forum/viewforum.php?f=43

Have a read through and ask some questions if you need clarification on anything.

 

[Curbcast]

Yeah Ive read (the manual under the seat) enough to ...not get it? haha. Ill dig in a bit better & try to understand. I just dont know when you are supposed to use your feeler to gauge clearance & What is TDC (when looking at the valve arm etc)

To the books!

 

[Sonreir]

You can't find TDC (reliably) by looking at the rocker arm. You have to look at the crank.
Roughly speaking, TDC will be when the arm is up and the valve spring is fully expanded. This is something you need to get better than "pretty close" though. So take the time to do it right if you're in for some pretty big headaches (and possibly pretty big parts/labor bills) later.

Check out this thread when you get a chance, as well:
http://www.dotheton.com/forum/index.php?topic=23171

 

[HerrDeacon]

Here's a decent video that may clear up a few things. How To Adjust Valves.

 

[DrJ]

Adjust valves when piston is at TDC at end of compression stroke (not at the exhaust stroke). That's when both valves are completely closed and both intake and exhaust rockers are slack without any load from the cam. You can wiggle both rockers with your fingers when the crank is in the correct position. It helps to visualize if you remove the spark plug and look down at the piston and valves and watch them move.

 

[Curbcast]

So the TDC of compression stroke is when the valves are slack. Which means there is no compression in cylinder. KK gettin it.
Intake stroke DOWN
Compression stroke UP
Power stroke DOWN
Exhaust stroke UP

 

[Curbcast]

Intake stroke. Intake valve OPEN/Exhaust valve CLOSED
Compression stroke. Both valves CLOSED
Power stroke. Both valves CLOSED
Exhaust stroke. Intake valve CLOSED/Exhaust valve OPEN

Jesus Im actually getting it. Thanks guys!

 

[Sonreir]

Mostly right. There is some overlap between the valves. At some points in the cycle both valves can be open and sometimes the valve will open early and/or close late.

 

[Curbcast]

Turns out I didnt even know the 4 strokes of 4 stroke. Its fun to learn. Thanks for the words, Im gonna dig into this adjustment wed night (1st night of welding school tonight!) If I have any issues Ill post em up.

Then cam chain!

 

[bobjohnson]

If youre having trouble getting the pistons at TDC, what you can do with rocker arm style valves (like you have) is just spin the crank and watch the rocker arm. When you can wiggle the rocker arm freely, its ready for adjustment. Then just work your way around. You spend more time spinning the crank by hand, but if you have a bike that just absolutely will not sit at TDC (my little 125 wont, clicks past every time, or rolls over under its own weight) it saves a lot of time. If theres only 4 valves i just end up doing it this way, If you have 8 valves or 16 valves on a SOHC, then yeah it pays to get it lined up at TDC.

 

[CBnewB]

Can one of you fine gentleman like riders post a video of this process? I got confused just reading this.