I think I bent my valves

i watched a guy insert the cams in the way the manual showed...except it was the wrong side of the picture or some wrong page and he was 180 out and bent a valve...it was fixed in a week of running around and getting old parts...lapping and stuff....it happens ...this guy worked on bikes for twenty years and i at the time knew z-motors...we were both talking and working and it was a bummer.......

Also be sure and use the right marks. Many a valve has been bent by using marks that are there just to goof you up. Not by me of course though. These are "other guys" that do this mistake.:laugh:

I get two of the same pictures? Here's the other cam I hope.

Yep, this is exactly what happened. I got the intake one correct, but the exhaust one has two marks 180 degrees apart. One mark is a line, the other is just frikkin barely an arrow.

Also, with the cam set incorrectly (the line on the right side and not the arrow), the EXH symbol shows above the edge of the head... You would think they would stamp the exh where it's visible when installed correctly... but nope!

Still I can only blame myself for not looking at the cam lobes and using common sense as to what should be open and closed at TDC and through the 4 strokes...

PLUMMEN wrote:

picture your intake and exhuast valves trying to occupy the same space at same time!:blink: or rosie odonnel and roseann barr both trying to occupy the same porta potty,it aint a purdy sight!:laugh:

ew, too much information

thenorm wrote:

Yep, this is exactly what happened. I got the intake one correct, but the exhaust one has two marks 180 degrees apart. One mark is a line, the other is just frikkin barely an arrow.

The 750 twin cams also have two marks that are 180 apart. If you set it to TDC and align to the correct marks, they face away from each other and are parallel to the head surface.

If you rotate the crankshaft 360 to the next TDC, the cams only turn 180 degrees and the "other" set of arrows are now pointing away from each other and parallel to the top of the head.... and the correct arrows are pointing towards each other.

The first time I did my cams and was checking the valve clearances by turning the crank, I returned it to TDC and saw my timing marks pointing at each other and FREAKED..... not realizing the cam turns 1/2 rev for every rev of the crankshaft.:laugh: