Adjusting cam timing on GS550E

[Nessism]

Time to start over.

1) remove cam chain tensioner

2) Set 1-4 T mark (you have 1-4 F mark aligned which is wrong)

3) Exhaust cam 1- mark must align with the gasket surface. Remove cam chain and reposition as necessary until you achieve this. After you do, use the vice grips to clamp down on the cam. After you do this, double check your 1-4 T mark to make sure it didn't move.

4) Set the intake cam position as needed until you get 20 pins between 2 and 3. A vice grip is good to press down the cam into the cam journals so you are not stressing the cam cap bolt threads too much.

5) install cam chain tensioner after you push in plunger and set locknut. After tensioner is installed, release plunger, back off setscrew 1/2 turn and retighten locknut



N

I have been getting fuel into the airbox and started a thread in the Carb section because I assumed I had an overflowing carb issue. With tom203's guidance, I started looking at the cam timing which apparently could cause back pressure and explain the symptoms I'm having.

It seems that my cams are 180 degrees off and my intake cam is off by 3 pins or so.

I guess first, I'd like to confirm I'm reading things correctly. With crank at the 1-4 F mark, the 1-mark on the Exhaust sprocket is more or less flush with the gasket surface. At this position the 3-mark on the Intake sprocket seems to be 23 pins away from the 2-mark on the Exhaust sprocket. If I continue turning the crank clockwise, I come to T mark which I assume is the 1-4 T mark. In this position, the 1-mark on the Exhaust sprocket seems to be flush with the gasket surface but pointing back instead of forward and the other relevant marks not visible on the sprockets.

Here are the pics with the crank at the 1-4 F mark.
Crank / Ignition Plate

Sprockets:


The manual specifies 20 pins and there are roughly 23. Do I leave the exhaust sprocket alone and just adjust the intake sprocket by 3 pins? Reading another thread, I got the impression that being 180-degrees off is not a problem but I may have interpreted that wrong. Also, is it odd that my sprockets have different numbers on them? 470 In / 471 Ex? Most of the pics I've seen that include numbers, show them as the same. The sketches in the 550 manual and Clymers don't show numbers.

I've been reading other posts trying to figure out how to do this. If I'm understanding correctly, this post from Nessism in another thread seems to sum it up (after removing the cam chain tensioner):

To set cam timing do the following...

1) Set the crank to the 1-4 T mark

2) Check the position of the 1- mark on the exhaust cam. It needs to be pointing at the gasket surface. If necessary, remove the cam chain from the sprocket and reposition the cam. Do not allow the crank to move - double check that it's still at 1-4 T. Get a large pair of vice grips and press the cam into the engine, compressing the valve springs. Do not use the bolts on the cam caps to press the cam down into the springs.

3) Count the link pins between the 2 and 3 marks on the cams and adjust the intake came as necessary.

The key here is to set the crank and then don't move it at all. Don't allow it to move. Keep checking to make sure it didn't move. Get the clue?

I'm not clear on the vice grips part. Does pushing in a cam with the vice grips create the slack that allows me to remove the chain and rotate the sprockets? Or is this after the chain is off and just allows rotating the sprocket? Which cam do I push in?