Working on a Perkins AD3.152

So..... could you clarify what component each of those gears is attached to?

I want to assume the bottom is the crank, big one in the middle is cam and the one on the left is fuel pump. If so, I'm guessing that the engine probably uses mechanical injectors instead of an inline pump since the crank and fuel pump gears are roughly the same size.

 

Ah ok. Didn't see the top of the pic.

Betcha its a hunting gear pattern. Might have to spin it over a dozen times or so before everything lines up with the idler.

 

Bingo winner !
With that design you would have to turn that engine over multiple times before the timing marks will come in to line again.

 

It's a hunting tooth design. The thing to do is not assume your smarter than it and count teeth to keep from tearing it apart and lining everything up. Do it by the book and line everything up or post later with more problems. The rope seal just threads in the groove pretty self explanatory

 

Was the rope seal pushed all the way down in to the grove in the block and in the grove in the rear main bearing cap?

 

Keep track of how many turns you make but I bet if you start turning it a few times, the timing marks will start getting closer together and eventually line up.

It can be a hard concept to grasp at first. Your cam spins at half crank speed (2:1). The idler simply transmits power. In a hunting pattern, the idler has a wacky number of teeth compared to the crank and cam. Basically meaning the marks may not line up every revolution (may take a dozen or more) but they're still in time.