[Homer]

hello.

so im still checking a few things at a time on a z50 i bought a couple weeks ago. i continue to find surprises, but thats the fun part. learning to fix them.

so i have the flywheel cover off and timed the points correctly using the marks on the flywheel and motor. i kept wondering why a black marker spot was slightly to the left of the motor's fixed mark. now i know!

i took the cam cover off because i wanted to know for sure the timing was right so i could do an appropriate leak down top dead center test (my test was showing 80psi and it made me wonder why).. the black marker spot from the prior owner is the "real" top dead center from when he must have put the motor together. so i have a couple of questions now.

Q1 - if he marked TDC with a marker slightly to the left of the real motor mark, and if he timed the points against that black marker spot which was representing "his" TDC, would that mess anything up or is it all the same and he simply timed it (if he timed it at all) based on his black mark?

I wanted to correct the situation anyway so i popped the cam sprocket off and adjusted it so it aligned with its mark while the flywheeel is marked with it's motor mark and the T on the flywheel. but now i cannot get the sprocket back on, its like 1/8th in. too short with a fully extended tight chain. this lead me to think to loosen the tensioner adjusting bolt's "A" and "B" (B being the one on the bottom and not next to the shifter).i loosened A and B to the point where oil would begin to leave the motor on B and i could see some oil on A's inner half.

Q2 - the cam chain is still too tight and i gained nothing in regard to getting the sprocket back on. shouldnt have loosening both of those taken care of the job or do i need ot drain the oil and completely remove the tensioner rod components (adjuster B) to let the chain become more loose?

Q3 - im still confused as to how it somehow is tighter now than it was when i simply took it off (the inside tensioner literally moved maybe?)

Q4 - what is the purpose of tensioner adjustment "A"? is it to fine-tune the tension while tensioner B is to coarse turn the tension?

Q5 - last one, when do i know i have enough tension (based on play maybe?)

Here are pics of those marks i was talking about from the prior owner. kind of hard to see but the black mark is next to the flywheel T (pretty much aligned i must have bumped it) and the O on the cam sprocket is aligned with its mark that you cannot see in the pics.

 

[Little Red Zed]

Hi,
Q1 I would just set the base timing again the proper way. Flywheel notch on "T" and the cam sprocket "O" on the cylinder head notch.
Q2 If you take out the tensioner screw assembly a little oil will come out. Just make sure you lean the bike a little more on the right side if you can.I`ve had good luck just loosing the "A" adjusting bolt.
Q3 The only think i can think of making it tighter if cam chain tensioner roller gear fell off or something?
Q4 I think the A adjustment is for quick adjustment and the B is for setting the tensioner spring tension.
Q5 If you go by service manual specs, the end play on the chain will self set if the chain and gears are in good shape and not stretched or worn out.

There`s a nice manual in the tech section on this site if you don`t have one.

 

[Homer]

thanks.

follow-up for others.

so i leaned it to the right, pulled the tensioner push rod out and got only little oil as you mentioned. once i took it out the cam still wouldnt go on and was tight. so i poked a long skinny screwdriver into the tensioner rod hole slowly and i bumped something (maybe the tensioner arm or roller?) and instantly i had my cam chain play back and was able to put it right back onto the cam. so something with the roller or maybe arm was binding the chain until i bumped it. it must have happened when i pulled the cam sprocket off initially.

timing marks are as they are supposed to be now. yippie!