1980 GS550 Camshaft Installation Question

[glstine]

I finally got my cylinder jugs on and head. I'm a little confused as to aligning everything properly to install the camshafts. There are radial lines at the signal generator about 10 degrees apart, next to the first one there is a T next to the second one there is an F there is nothing at the third one. Between the second and third lines are the 1-4 marks. I'm not sure how this is supposed to line up for TDC. Any advice would be appreciated.

Also my camshafts don't sit flat when lined up with the 3-2-1 marks in the right position (that is some of the lobes are pointed downward). Of course this is with them just laying there not tightened down. Is this correct? If so how do you get them lined up properly with it cranked down, I don't see being able to turn them at that point.

Hope that makes sense.

[Steve]

Do you not have a manual? They all describe the process.

Line up the crank with the T 1-4 mark, this puts the pistons at TDC. Pull the cam chain to remove slack, especially the front side. Line up the exhaust cam so the #1 mark is pointing at the edge of the head. It is the numbered marks that are critical, not the direction the lobes are pointing. Pull the cam chain into place over the exhaust cam. Count out the proper number of links from #2 on the exhaust cam to #3 on the intake cam, tighten the retainers on the intake cam. (Your manual will tell you the proper number of links.) Install the cam chain tensioner, rotate the crank clockwise (forward) at least two full turns, listening for any strange noises. Watch for the tensioner to remove more slack while you do this. Check your alignment marks to make sure nothing has moved out of place.

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[hampshirehog]

Ok - a bit tricky to explain this one but here goes.

Looking in the ignition side set the mark immediately to the left of the T (next to F1.4) exactly in line with the mark on static plate. Cylinders 1 and 4 are now at TDC. Turn the engine forward to achieve this and feed the cam chain in carefully to avoid snagging.

Now put the exhaust cam in to position. Without moving the bottom end pull the chain tight and engage on the sprocket so that the No 2 arrow is pointing up vertically and the No 1 arrow on the front of the sprocket is pointing directly at the top of the cylinder head.

Using a clamp, hold the exhaust cam down in position and pop on the cam caps.

Next position in the inlet cam. Count 20 pins across on the chain (no 1 is directly in line with the 2 arrow on the exhaust). It's easier if you mark that 20th pin with a bit of felt tip / nail varnish etc. Turn the inlet cam until the 3 arrow points at that 20th pin. Now pop on the inlet cam caps, again clamping down so that you tighten things up evenly and there is no stress anywhere.

Insert the bridge guide and then the cam chain tensioner. Have a look at the manual for guidance on how to do this.

You're right that the cams won't lie flat when the timing is right. There's always at least one cam lobe pointing down on these bikes.

[glstine]

The markings I have for the crankshaft are different from the manual (there is no F1.4 mark, just the ones I described). I will see if I can get a picture of them.

[Larry D]

Pics are the best around here...everybody loves 'em. Especially when trying to explain something like this. Here's how via BassCliff's wonderful site.

http://members.dslextreme.com/users/bikecliff/images/how_to_post_pictures.pdf

[glstine]

Here's a pic

[Steve]

That T mark just left of center is what you want to line up with the outer mark that is probably hidden in the shadow. Then tension your chain a bit, line up #1 on the cam with the edge of the head, etc.

The T mark is Top Dead Center (abbreviated TDC).
The F mark is where #1&4 should fire at idle speed.
The mark over the 4 is where they should fire at higher speeds (I think that's over 3,500 rpm or so).

.

[glstine]

Thank you much. Hopefully I'll be firing this thing up soon, it's been along time coming.

[chef1366]

You need to put the inner ignition plate on for the main timing mark.

[Nessism]

[Steve]

Be sure to count pins carefully on the cam chain. You are not counting pins between the cam marks, you need to include the pins at the cam marks, too. That is, #1 pin will be directly over the #2 mark on the exhaust cam and #20 pin will be directly over #3 on the intake cam.

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[glstine]

My clymer manual does not have this picture (unless I missed it somehow). That sure would have been helpful. Thanks for the replies, this is a great forum.

[Herzie]

Old thread I know, but I have a question on this matter.

When tightning the camshaft lobes down should I apply a pressure to the raized part of the camshaft to help it compress the pistonsprings? I'm asking because I fear that the threads in the head will be damaged if I compress it with the bolts.

I hope this made sense

[Nessism]

The Suzuki service manual shows using a large set of vice grips to compress the cam into the head before installing the caps. I’ve used this method before and it works great.

[Herzie]

The Suzuki service manual shows using a large set of vice grips to compress the cam into the head before installing the caps. I’ve used this method before and it works great.

Okay thank you. Has anyone used something that I'm more likely to have in the general toolbox?