Should I Change the Oil Again After Valve Adjustment?

I just finished my winter maintenance. I started with an oil change (which in hindsight was a mistake). I also replaced the coolant, brake and clutch fluid, fork oil, rear pads, plugs, radiator cap, and checked the valves. I was surprised to find all of the exhaust valves, and one intake valve out of spec. I went ahead and adjusted them. The manual calls for a mix of 50/50 moly grease and motor oil for the cam lobes, bearings, and gears during reassembly. My question is, if it was your bike, would you change the oil again due to the moly grease in there? I'm leaning towards changing it, though I'd rather not if I don't have to. Thanks in advance.

Nope, I'd leave it, no reason to change it. Moly is good for bearings and won't hurt a thing. It will be dispersed soon enough.

jfheath said:

The 50-50 moly mix is to enure the lobes are lubricated at the first firing up.

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+1...
When doing a full engine overhaul/rebuild one is advised to lube all journals with a dab of Graphogen or Moly Assembly Paste (the one we use on drive splines) to ensure nothing runs "dry" during the very first cranks of the engine, as the oil pump requires a few rotations to build up pressure.
When you only removing the cams for valve adjustment, just smear a finger tip engine oil across the journals before dropping them back in.
BTW ensure that there is no oil inside the blind holes of the bolts holding the bearing plates; place a rag over the head and blow them free with compressed air prior reassembly.

RaYzerman said:

Nope, I'd leave it, no reason to change it. Moly is good for bearings and won't hurt a thing. It will be dispersed soon enough.

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+1 , here too.

But I admit I'm kinda cheap .............

fnmag said:

What is the mileage on your ST?

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50k

jfheath said:

I wondered what you were probably thinking

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ST1100Y said:

When doing a full engine overhaul/rebuild one is advised to lube all journals with a dab of Graphogen or Moly Assembly Paste (the one we use on drive splines) to ensure nothing runs "dry" during the very first cranks of the engine, as the oil pump requires a few rotations to build up pressure.

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I was thinking of the assembly lube used during a full rebuild. I know the oil needs to be changed after initial break in.

Glad to hear the consensus is no oil change needed! Time to button everything back up (actually, all I have left is the lower fairing).

I'd be more concerned that all the exhaust valves were out of spec. I personally have never read here of all being out of spec. How much out? And with such low miles! You're positive you used the correct size feeler gauges aren't you?

I have a 50,000 mile ST1100 in my shop that needs six valve clearances adjusted. Mine only took one shim at 44,000.

ZIAMON said:

I'd be more concerned that all the exhaust valves were out of spec. I personally have never read here of all being out of spec. How much out? And with such low miles! You're positive you used the correct size feeler gauges aren't you?

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I know that the conventional wisdom is that they should'nt be out of spec until higher mileage. That's why I was so surprised. They were all either .006 or .007 which is not even close (should be .009-.011). I double checked my measurements (as in measure twice, cut once ha ha).

RobbieAG said:

I know that the conventional wisdom is that they should'nt be out of spec until higher mileage. That's why I was so surprised. They were all either .006 or .007 which is not even close (should be .009-.011). I double checked my measurements (as in measure twice, cut once ha ha).

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OK, gotta ask. Are you sure you weren't confusing the exhaust with the intakes, because .006/7 is intake valve territory. Maybe the PO confused them and adjusted them wrong?? That far out of spec on all the exhaust valves is not only not normal, I'd go so far as to say its nearly impossible. My money is on somebody mis-adjusted them at some point in the bike's history.

Certainly something not seeming to be right there. Exhaust valves that tight should have burned.

dwalby said:

OK, gotta ask. Are you sure you weren't confusing the exhaust with the intakes, because .006/7 is intake valve territory. Maybe the PO confused them and adjusted them wrong?? That far out of spec on all the exhaust valves is not only not normal, I'd go so far as to say its nearly impossible. My money is on somebody mis-adjusted them at some point in the bike's history.

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I'm sure I didn't confuse the intake and exhaust, but it's entirely possible somebody did in the past. I have very little in the way of maintenance history on the bike before I got it two years ago. It's possible they were never adjusted or even checked before.

RobbieAG said:

I know that the conventional wisdom is that they should'nt be out of spec until higher mileage. That's why I was so surprised. They were all either .006 or .007 which is not even close (should be .009-.011). I double checked my measurements (as in measure twice, cut once ha ha).

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dwalby said:

OK, gotta ask. Are you sure you weren't confusing the exhaust with the intakes, because .006/7 is intake valve territory. Maybe the PO confused them and adjusted them wrong?? That far out of spec on all the exhaust valves is not only not normal, I'd go so far as to say its nearly impossible. My money is on somebody mis-adjusted them at some point in the bike's history.

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Bush said:

Certainly something not seeming to be right there. Exhaust valves that tight should have burned.

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I agree with Doug and Forest... there's something wrong here.

John

While it?s possible that the previous owner or a careless mechanic misadjusted the valves in the past, it?s just as possible that they?ve never been adjusted and are just out of spec. I don?t think being .002 - .003 too tight is enough to cause major engine damage ? it doesn?t appear that it did in this case. It was running fine before the adjustment and is running fine now. Time will tell how well it keeps running.

RobbieAG said:

it’s just as possible that they’ve never been adjusted and are just out of spec.

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there is a lot of empirical data between ST1100 owners on this forum, and nobody has ever had anything close to your out of spec condition. Most STs will need a few minor adjustments of .001/2 sometime in the 50k-100k mile range, on a valve or two. You having all exhaust valves off by .004 at 50k miles is more than just coincidence, but its good to know that the bike can be that far out of spec on the most critical (tight exhaust) side and apparently not do any permanent damage.

dwalby said:

You having all exhaust valves off by .004 at 50k miles...

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For the record, the clearances were all .006 or .007, so they were off by .002 or .003.

RobbieAG said:

For the record, the clearances were all .006 or .007, so they were off by .002 or .003.

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Your figures are correct wrt the minimum clearance spec, but most people will shoot for the mid-to-upper end of the range when adjusting them because in theory too tight is worse than too loose. Based on that they all needed a .004 thinner shim, which is what I was referring to. But your bike may have contradicted the "exhaust valves that are too tight is very bad" theory, if you put many miles on it in that condition.

dwalby said:

Your figures are correct wrt the minimum clearance spec, but most people will shoot for the mid-to-upper end of the range when adjusting them because in theory too tight is worse than too loose. Based on that they all needed a .004 thinner shim, which is what I was referring to. But your bike may have contradicted the "exhaust valves that are too tight is very bad" theory, if you put many miles on it in that condition.

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I agree with this and did shoot for the middle to upper end of the range when I adjusted them. However, if they were all at .009, I would have considered them in spec and left it alone. I also agree that exhaust valves being too tight is very bad, but being out by .002 or .003 is apparently not tight enough to cause major damage.

I think this shows that you should always check and never assume anything, especially when dealing with purchasing a used bike. It also reminds me why I prefer to do my own maintenance.

I would say, if they are few thousandth's too lose, that won't cause a problem. But if a few too tight, it may be a problem since you are measuring the clearance with a cold engine.

Who knows what the clearance is when hot ? I know of a guy with an old Moto Guzzi who set his valves too tight by mistake. The bike ran fine until he slowed down to stop. The bike stalled and wouldn't re-start until it cooled down. Apparently when hot, either the intake or exhaust valves ( or both ) were being held open slightly and the engine wouldn't start because of a lack of compression.