Do I have major trouble in "Big Red" land??

[Guest]

I apologize for the threadjack, but I have a question that pertains to this.... If you can't rotate the crankshaft with the camchain tensioner out, how do you line up the timing marks to set the valve timing when you are installing the camshafts? Not that I did something as stupid as removing the cams without lining up the crank first... No, nothing like that...this is just a "what if" question, yeah...that's it....

You don't want to rotate the crank with the cam chain tensioner out when the cams are still in place, that's what I was trying to do & that results in the piston whacking the "opened" valve because the chain length is different when the tensioner is removed & the engine is no longer in time...

No problem once the cams are out, there's no lobes to open the valves without the cams.

To reinstall the cams, first pull the chain up by hand to keep some tension on it (don't let it slip back down the tunnel) & slowly turn the crank to the proper timing mark. Put the cams through the chain loop, & lay them on their journal surfaces (without the caps). Without moving the chain/crank, rotate the exhaust cam to the correct mark (#1 arrow pointing forward & flush with the head surface I believe) and then engage the chain. There should be a #2 arrow pointing straight up on that exhaust cam, now count the proper number of chain pins to align the #3 arrow on the intake cam.

I'm not sure exactly of the pin numbers & such, so check your manual for the correct alignments, but the procedure is the same.

Take care to line up all the marks (crank, cams, pins) EXACTLY... one tooth off will drive you nuts because the bike will not run right. Check & double check & triple check your alignment.

Good luck - I'll be doing the same very soon myself.

[sam78gs750]

You don't want to rotate the crank with the cam chain tensioner out when the cams are still in place, that's what I was trying to do & that results in the piston whacking the "opened" valve because the chain length is different when the tensioner is removed & the engine is no longer in time...

No problem once the cams are out, there's no lobes to open the valves without the cams.

Thanks for clearing up my confusion. I have the service manual and am pretty clear on the procedure for lining everything up. I just read the responses to your post and got worried that I screwed up by not lining up the crank before I took the cams out. Everyone got all serious about not rotating the crank with the tensioner out...I didn't realize that they meant the warnings for only while the cams are still in.

[Guest]

Thanks for clearing up my confusion. I have the service manual and am pretty clear on the procedure for lining everything up. I just read the responses to your post and got worried that I screwed up by not lining up the crank before I took the cams out. Everyone got all serious about not rotating the crank with the tensioner out...I didn't realize that they meant the warnings for only while the cams are still in.

I hear ya... I'm the idiot who was trying to turn the crank after removing the tensioner, and wondering why it wouldn't move!

One trick to verify the 1 & 4 pistons are at the top (T mark) is to put a wooden dowel (new pencil) down the spark plug hole of # 4 and watch it go up & down while you turn the crank - should be at TDC when the 1/4 T mark is lined up.

[Guest]

I hear ya... I'm the idiot who was trying to turn the crank after removing the tensioner, and wondering why it wouldn't move!

One trick to verify the 1 & 4 pistons are at the top (T mark) is to put a wooden dowel (new pencil) down the spark plug hole of # 4 and watch it go up & down while you turn the crank - should be at TDC when the 1/4 T mark is lined up.

With the cams out it makes no difference. TDC is TDC 1&4 either way. With the cams in every other is the compression stroke for 1 or 4. It alternates between 1&4 cylinders.

[Guest]

With the cams out it makes no difference. TDC is TDC 1&4 either way. With the cams in every other is the compression stroke for 1 or 4. It alternates between 1&4 cylinders.

hey bill,

can you elaborate a bit on this... does the 1/4 T mark goes around twice for each complete piston travel cycle; so you could be 180 out?

[Guest]

hey bill,

can you elaborate a bit on this... does the 1/4 T mark goes around twice for each complete piston travel cycle; so you could be 180 out?

Everytime the trigger passes the 1&4 is the fire stroke for either 1 or 4. So both pistons are all the way way up but the cams determine if it is a compression stroke. So if your timing is off 180 it is with the cams and not the crank.