Cam Chain Tensioner & timing Question

[Dphillips030]

So long story short i've been rebuilding the top end to my 78 gs1000. It's the first time that i have done this. Ive got the timing marks lined and the cams in with the cam chain around it. Problem is... When i put the cam chain tensioner in, it turns the crank a hair and the TDC mark is no longer lined up. Question is: Should this TDC (cyl1-4) mark still be lined up exactly once the cam chain tensioner is applied? Is it normal that it moves a little like this?

[Steve]

If it's only "a hair", it's not a problem.

Before you button things up, double and TRIPLE check the count between the #2 and #3 marks.

It catches a lot of people that the pin over the #2 mark is your #1 pin, not the one next to it.

.

[GregT]

When you let the tensioner out, it takes up the slack on the back run of the chain. Yes, this may move the crank.
Once it's in and locked it should be possible to realign the marks at the crank end and check that the marks on the cam sprockets are correctly aligned - #1 level with the head face and #2 and 3 the right no of pins apart.

[tom203]

Note pins ,note slots on camshaft ends

image.jpg

[Dphillips030]

I have it all set up correctly with the 1,2,3 marks on the cams and the number of 20 pins from marks 2&3. The only thing that I don't have in it is the front cam chain guide but I feel like that shouldn't make much of a difference on the crank turning from them tensioner. I can release the tension on the tensioner by turning the large knob and turn the crank to get the timing marks close but it still seems to be off when I rotate the crank a few revolutions.