Right this is really confusing me did the timing belt on my tiger Avon about 6 months ago ran the car a few times no problem what is confusing me is the slack on the timing belt. When I turn the engine over by hand there is a difference in the slack between to cam gears. When it feels like a compression stroke the belt is nice and tight as soon as it gets past that the slack between the cam gears is about 15mm just doesn't look right?

 

Is the tensioner tensioned correctly, it's not come undone/slipped?

When you fitted the belt, did you lock the cams and slacken the cam pulleys before you tensioned the belt?

19 hours ago, phaeton said:

Is the tensioner tensioned correctly, it's not come undone/slipped?

Tensioner is still tight all torqued correctly 

16 hours ago, richyb66 said:

When you fitted the belt, did you lock the cams and slacken the cam pulleys before you tensioned the belt?

Yes, cams locked with proper tool and cam sprockets loosened off, tightend the tensioner first and then cam gears 

Should be correct then. The real test would be whether you can get the locking tool back in but personally I wouldn't worry about a bit of slack between the cams when it's not running. Any slack soon disappears once the belt is moving.

the usual "mechanic" test is can you twist the belt on the longest straight run 90 degrees.

If less its ok, if more its too loose.

1 hour ago, Bob Tucker said:

the usual "mechanic" test is can you twist the belt on the longest straight run 90 degrees.

If less its ok, if more its too loose.

That's for an auxiliary belt not a timing belt

Always used the 90 degree twist method on Pinto cambelts. The more modern stuff usually has pointers on a spring loaded tensioner that have to be lined up.

1 hour ago, richyb66 said:

Always used the 90 degree twist method on Pinto cambelts. The more modern stuff usually has pointers on a spring loaded tensioner that have to be lined up.

I stand corrected then, not had a boat anchor since the very early 80's but you'll not get away with that much slack on more modern stuff