Adjusting cam timing on GS550E

[scott]

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?

 

[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

 

[tom203]

Scott quote.. " 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? "
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Get the crank "T" mark and exhaust mark "1" as Nessism stated- is your exhaust camshaft timed correctly to crank already? If it is, you don't want it to move as you attempt to relocate chain on intake camshaft- it (the #1 mark to the "T" crank mark ) must be held fixed as you fiddle with intake camshaft. Me, I would wedge a piece of wood between the exhaust camshaft gear and the head to hold chain and exhaust camshaft fixed.
Apparently, there is not enough slack in chain to "just lift it and reposition it" on intake cam gear after you remove the cam chain tensioner- or is there??? I'd spend some time trying! Otherwise you are going to have to remove the bearing caps on the intake camshaft ( two caps -4 bolts each). But these caps are fighting valve spring pressure and that's where the vicegrip clamping stuff comes in. Unlike pic, your engine is still in frame . I would first see if just removing the tensioner MAYBE gives you enough slack to reposition intake camshaft gear into correct spot. It's worth finding out- maybe your 30 year old chain has stretched enough- I will light candles !

 

[scott]

So if I'm understanding correctly, the removal of the cam chain tensioner is creating extra pressure on the cam cap bolts. As long as I don't need to rotate either camshaft, vice grips should be used to alleviate this pressure. So I shouldn't just take off the cam chain tensioner and leave the bike in that state for days without vice grips on both intake / exhaust camshafts.

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.

The pic says "vice grips are used for each camshaft to hold down the tappet interfering with a cam". In this position, the Ex Cam #2 lobe is "pointing down". I don't see any way to get vice grips on the Ex Cam #2 lobe with the frame in the way. Only #1 and #4 seem accessible so I guess I just pick one. I take it this won't marr the lobe surface. And I keep this vice grip here until step 5 is completed.

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.

So after I have the intake sprocket positioned with 20 pins, I put another vice grip on the intake side to keep pressure off while I'm doing step 5.

Get the crank "T" mark and exhaust mark "1" as Nessism stated- is your exhaust camshaft timed correctly to crank already?

Unfortunately no - it seems like the exhaust cams are timed to the "1-4 F" mark instead of the "T" mark. I assume that means it is 180 degrees out. It sounds like I need to adjust both the exhaust and the intake.

Apparently, there is not enough slack in chain to "just lift it and reposition it" on intake cam gear after you remove the cam chain tensioner- or is there??? I'd spend some time trying! Otherwise you are going to have to remove the bearing caps on the intake camshaft ( two caps -4 bolts each). But these caps are fighting valve spring pressure and that's where the vicegrip clamping stuff comes in. Unlike pic, your engine is still in frame . I would first see if just removing the tensioner MAYBE gives you enough slack to reposition intake camshaft gear into correct spot. It's worth finding out- maybe your 30 year old chain has stretched enough- I will light candles !

I hope I can just move the chain but we'll see. I haven't read that I need to remove bearing caps ... yet.

I ordered the o-rings/seals/etc. for the cam chain tensioner but I guess I don't need those until Step 5.

 

[Nessism]

You have to remove the cam chain tensioner to get slack on the cam chain. Then the cam caps must be removed before you can adjust the cams. The cam cap bolts will be under tension because some of the valve springs will be pushing up. The idea with the vice grips is to hold the cam tight in the head so the threads on the caps don't strip out when you tighten/loosen the bolts.

You don't actually need the vice grips, it just makes the work easier. When you clamp down on the cam you don't touch the lobes, just the portion of the camshaft that is in the middle, next to the sprocket.

BTW, the exhaust cam is not 180 degrees out of alignment, more like one tooth on the chain. You might want to put a paint mark on the cams and sprockets so you can count how far to move them when you adjust.

 

[tom203]

Scott quote..."So if I'm understanding correctly, the removal of the cam chain tensioner is creating extra pressure on the cam cap bolts. As long as I don't need to rotate either camshaft, vice grips should be used to alleviate this pressure. So I shouldn't just take off the cam chain tensioner and leave the bike in that state for days without vice grips on both intake / exhaust camshafts"



No, the valve springs are pushing up on camshaft- the tensioner just takes up chain slack. The cam cap bolts ( high grade steel) are tapped in soft aluminum head. As you loosen cap bolts (just before they come out of tapped hole) , valve spring pressure will strip out the last couple threads in the soft aluminum- you have to make sure this doesn't happen! You need a method of holding down camshaft ( but not on lobes) until you get the cam cap bolts completely out and then you can orient the camshaft correctly. Then you also have use your holding/clamping method to reinstall the cam cover bolts fully into aluminum head . Note that caps might be marked and oriented precisely- note/mark left/right facing forward, etc.
Relooking at that pic with mark #1 facing forward and mark#2 vertical, I think Nessism is right and your exhaust cam is off 1 tooth.

 

[Nessism]

The exhaust cam is most likely one tooth off, and the intake cam is three off since there are 23 pins between the 2 and 3 marks, and there should be 20.

 

[scott]

You have to remove the cam chain tensioner to get slack on the cam chain. Then the cam caps must be removed before you can adjust the cams. The cam cap bolts will be under tension because some of the valve springs will be pushing up. The idea with the vice grips is to hold the cam tight in the head so the threads on the caps don't strip out when you tighten/loosen the bolts.

You don't actually need the vice grips, it just makes the work easier. When you clamp down on the cam you don't touch the lobes, just the portion of the camshaft that is in the middle, next to the sprocket.

Oh okay, I didn't realize I had to take those caps off. I was thinking I would just ... rotate the sprocket once the chain was off. It seems I should be somewhat following the Camshaft Removal / Installation part of the Clymer manual but instead of fully removing / sliding out the camshafts, I will rotate them to the correct position. That middle part of the camshaft seems tough to reach with the frame there but I'll see what I can do. I have some clamps that I may be able to fit in there more easily. Most people aren't doing this with the engine OUT are they?

I still can't imagine what someone was doing to this bike to get both of these out of whack. With 7K miles, I was envisioning the bike spending most of its time in a shed. For all I know, she has been ridden around the world and this is a rebuilt engine or something.

No, the valve springs are pushing up on camshaft- the tensioner just takes up chain slack. The cam cap bolts ( high grade steel) are tapped in soft aluminum head. As you loosen cap bolts (just before they come out of tapped hole) , valve spring pressure will strip out the last couple threads in the soft aluminum- you have to make sure this doesn't happen! You need a method of holding down camshaft ( but not on lobes) until you get the cam cap bolts completely out and then you can orient the camshaft correctly. Then you also have use your holding/clamping method to reinstall the cam cover bolts fully into aluminum head . Note that caps might be marked and oriented precisely- note/mark left/right facing forward, etc.

Yeah, it seems like I was really misunderstanding. I think I would have messed up my cam lobes pretty badly! I thought the "cams" were the lobes.

I'm going to try this very slowly and hopefully won't do any damage. The Clymer manual also says to remove the chain slipper block and to tie a piece of wire to the chain to prevent if it from slipping into the engine. Since I'm not actually pulling out the camshafts, I guess the wire part isn't necessary. Not sure about the chain slipper block but I can't imagine that's too important.

 

[scott]

Just a quick update. I removed the carbs and the cam chain tensioner. I removed the chain slipper block, in case that is important. I picked up a pair of the largest Craftsmen vice grips they had (10R). There actually seems to be room with the engine in the frame. I haven't removed the cam cap bolts yet but I do have the exhaust cam clamped down (I think in the right spot). I had to unscrew the bolt on the vice grips "a lot".

This is taken from the left side of the bike:

Next step, removing those bolts.

Unless I'm doing it wrong, there does seem to be enough room on a 550ET with the engine in the frame to get a pair of 10R vice grips on the middle of the camshaft (in case someone with those exact parameters is wondering ... and someone doesn't chime in with a "NO you're doing it wrong!" ).

 

[rapidray]

What the HELL do you have the Vise Grips on there for?!!! Ray.

 

[tom203]

Just a quick update. I removed the carbs and the cam chain tensioner. I removed the chain slipper block, in case that is important. I picked up a pair of the largest Craftsmen vice grips they had (10R). There actually seems to be room with the engine in the frame. I haven't removed the cam cap bolts yet but I do have the exhaust cam clamped down (I think in the right spot). I had to unscrew the bolt on the vice grips "a lot".

Next step, removing those bolts.

Unless I'm doing it wrong, there does seem to be enough room on a 550ET with the engine in the frame to get a pair of 10R vice grips on the middle of the camshaft (in case someone with those exact parameters is wondering ... and someone doesn't chime in with a "NO you're doing it wrong!" ).

Well, rapidray chimed in, but didn't clarify his concern! Looks good to me- except for those UGLY chinese made "vicegrips". Remember mark orientation of cap covers before removal (front,exhaust,right, etc ). You obviously have a knack for this line of work!

 

[scott]

What the HELL do you have the Vise Grips on there for?!!!

Well that woke me up!

Remember mark orientation of cap covers before removal (front,exhaust,right, etc ).

Looks like Suzuki (or whoever made these caps) took care of that. They are marked A (Ex 1-2), B (Ex 3-4), C (In 1-2), D (In 3-4) with a triangle pointing forward. This is the Exhaust cap on the right side.

 

[Nessism]

Ray's point is you don't need the vice grips, and he's right strictly speaking. They are useful to seat the cam in the head journals and lock the cam in place thus my suggestion to use them. I've read lots of threads over the years here where people struggle and get the cam one tooth off after they crank down the cam cap bolts, thus sucking the cam down against the valve spring pressure. This is particularly true for the exhaust cam since it's sometimes difficult to tell if the 1 is going to point in the proper direction after the cam is seated.

I recommend using the vice grips for the exhaust cam but you don't have to for the intake since it's easy to time that cam by counting chain pins.

 

[scott]

What does it mean if I can't turn the crankshaft? I was planning to set it to the 1-4 T mark but it stopped turning for some reason.

EDIT: I don't have the vice grips on .

 

[Nessism]

Maybe the valves are hitting the piston. Might be best to remove the cams now, hold up the cam chain, and then carefully turn the crank where it needs to be then.

 

[scott]

Maybe the valves are hitting the piston. Might be best to remove the cams now, hold up the cam chain, and then carefully turn the crank where it needs to be then.

Ok - I removed the exhaust cam caps and pulled out the whole exhaust cam assembly. I put the cam slipper block back in. I tried rotating the camshaft and holding the chain up (note - the intake cam caps and assembly is still in) but it just seems to tighten the chain.

Can I turn the crankshaft counter-clockwise to loosen it?

Also, what the heck is in the cam caps? I noticed an odor as soon as the bolts broke loose but when I got them out and smelled them (bad idea), it was rancid - I actually had to get a drink of water.

 

[MisterCinders]

Yeah, the engine is hard to turn when the chain bunches up, so lifting the cam chain to lightly pull out the slack will allow you to line up the timing mark.

 

[Nessism]

Just pull both cams out. You can then rotate the engine as long as you hold up the cam chain.

Pull cams
Rotate engine to align 1-4 T
Install exhaust cam
Install intake cam
Install tensioner

 

[tom203]

"Also, what the heck is in the cam caps? I noticed an odor as soon as the bolts broke loose but when I got them out and smelled them (bad idea), it was rancid - I actually had to get a drink of water. "

Probably, a water-based coolant used during machining operations- trapped in the bottom of those holes ,I bet it smells real good after 31 years . Bon appetit!

 

[hampshirehog]

If you pull the cams to turn the engine over make sure that you don't let the cam chain drop down in to the tunnel (fiddly to get it back out) plus keep it tight in your hand to stop it bunching up at the bottom when you turn the engine.