Counting cam chain pins

[ohio750kat]

Hello...I am trying to finish the motor on my '97 750.I am not a professional wrench, but have rebuilt about 10 bike motors, and never had problems setting the cam timing before, even on V4 motors... Everytime I install the intake cam, the motor wants to bind up while i rotate it, and I can hear what I guess are the valves touching the pistons. If I remove the intake cam and hold the camchain up, it rotates fine. The notch on the exhaust cam is dead on. The intake cam always seems like it is maybe a tooth off, but I have 21 pins between the #2 and #3 marks on the sprockets. I am starting my count with the pin on the #2 mark and ending with the 21st pin on the #3 mark. That seems like the right way , but wanted to double check. Should I be loosening all the valve adjusters to set the cams, and then put them back in spec? I have not checked the cam chain for stretch yet, but I will be doing that tonight (hopefully).
Thanks in advance for any input or advice.....

[md86]

No , when I did mine it looked like it was a tooth off , but I triple-check my pin count , and even had a mechanic friend tell me I was doing it right . If I been slamming valves , I'da thunk after more than 10k miles , it'd be blowed-up by now ....

[Newbie2it]

You do have the cam chain idler pulley and the Cam Chain Tensioner installed and adjusted before you are attempting to turn the motor by hand? Correct? If not, the slacks the problem.

[arsenic]

uuummm, you can't count the pins with the idler gear on

[Newbie2it]

Nope, you sure cant, but by the time your ready to rock the motor back and forth, it should be in place.

[ohio750kat]

Problem solved

yup...idler gear was on.

Actually, I got it done Friday night. I pulled both cams and rotated the motor to reverify the crank turned ok. Then I reinstalled the intake cam first, and it dropped right into place, timing marks lined up perfectly, then the exhaust cam dropped right in place the first time also. I had been doing the exhaust cam first, so maybe that made the difference. Buttoned everything up, and a few cranks on the starter had it purring like a.......Kat

[Newbie2it]

Glad to hear you got it resolved finally

[ohio750kat]

update: blank, blank, blankity , blank

or I thought I had it.... Had my first chance to take the bike out thursday afternoon...I got two houses down the street and heard what sounded like a chain skipping across teeth on a gear....and then it stalled.....
I must be missing something... Guess it is time to try the manual tensioner I got in the box of parts with my bike...The automatic tensioner has a new spring, but maybe it is still bad...

Anybody in the Columbus area willing to help me out?

[md86]

Damn dude , that's rough . Perhaps the tensioner slipped , or the idle gears loosened up on ya (probably less likely ) . But the tensioner is easy enough to replace . Just gotta get the carbs out of the way to make it easier .

[Newbie2it]

Yikes... Might actually want to open the valve cover and find out what went wrong. If the chain snapped, or if the idler broke or the tensioner broke ect, you might want to pull the head off to make sure the valves didnt crash a piston. But that also would depend on what you find when you open the valve cover.

[md86]

Yeah , I was trying not to panic JUST yet .

[arsenic]

if it died, that's bad juju.

[ohio750kat]

It will still start but will barely run....Hoping to get into it tonight.....will update when I know

[Newbie2it]

Honestly, I wouldnt keep trying to start it, till you pop the valve cover and see what happened. Tho if it did crash, the damage is already done.

[arsenic]

bent valve, it's done