smokes for a minute after new valve seals

[DimitriT]

Well, the top end job on the 550 went smoothly but yesterday morning I noticed blue smoke for about a minute when it starts up. Goes away completely after a minute as far as I can tell and doesn't do it again until the next day.

I'm guessing its the valve seals. I replaced the originals with the ones included in the Vesrah gasket set. So I either got the install wrong or I got bad seals.

The install was very easy: I remove the old seals with pliers, I used a short socket with an extension and a dab of grease to hold the seal. I tapped the seal down over the guide and I inserted the valve into the installed seal. Everything looked too easy. Did I miss something? Could the seals have popped off the guides?

So now that I have this problem: should I worry about it? Should I take the head off again and fix it? Will it do any long term damage or clog anything up? I'm secretly hoping it will go away once the seals have shrunk a little but I know I'm dreaming.

The bike runs super otherwise.

[flyingace]

Does anybody know if this is normal? I'm bumping this because I'm planning to replace my valve stem seals this winter.

[Nessism]

No, it's not normal. There should never be any smoke like described.

Unfortunately, I'm not sure what to suggest other than what you already know. You might want to try to determine which cylinder is the culprit and then go from there. It might even be worth the effort to make some sort of compression tool so you don't have to pull the head again.

Good luck.

[DimitriT]

No, it's not normal. There should never be any smoke like described.

Unfortunately, I'm not sure what to suggest other than what you already know. You might want to try to determine which cylinder is the culprit and then go from there. It might even be worth the effort to make some sort of compression tool so you don't have to pull the head again.

Good luck.

Thanks for the reply. This bums me because everything else is perfect. No leaks and the bike runs awesome.

Do you see anything wrong with the install procedure as I described it?

[brveagle]

Did you do anything to the rings? You might need to give the seals a little longer to seat in.

[flyingace]

On paper it sounds like valve stem seals. Rings tend to smoke after the engine is running and warmed up.

Is there a way to tell if it's a particular cylinder (like which pipe smokes in a stock exhaust). If not stock, you should be able to look at your plugs soon after startup and see if any one cylinder has oily residue. Maybe only one seal is misalligned or something.

[DimitriT]

Well, if I wind up pulling the head for the second time I think I'll try a test where I fill up the spring holders with oil and see if any leaks. I'm wondering if I damaged the seals when I pushed the valve stem up through the opening. Should I have used a guide of some sort (I know this is recommended on some cars but I haven't seen any recommendations for the Suzuki). I'm getting smoke out both pipes with the right side giving me a little more. The wierd thing is the smoke stops as soon as it runs for a minute. I'm wondering if this is just left over oil on the stem (added during assembly) which is working its way out. Wouldn't a real leak smoke all the time as engine vacume would pull in more oil?

[salty_monk]

In a car they would smoke mostly under heavy acceleration & you'd also notice it on the dipstick.

Presumably the GS engine would be similar.....

It could smoke on startup cause it's sat & oil has time to creep past the seals I guess, if you've run it for a bit, got it nice & hot I would have though any assembly oil would be gone by now....

Dan

[flyingace]

Well, if I wind up pulling the head for the second time I think I'll try a test where I fill up the spring holders with oil and see if any leaks. I'm wondering if I damaged the seals when I pushed the valve stem up through the opening. Should I have used a guide of some sort (I know this is recommended on some cars but I haven't seen any recommendations for the Suzuki). I'm getting smoke out both pipes with the right side giving me a little more. The wierd thing is the smoke stops as soon as it runs for a minute. I'm wondering if this is just left over oil on the stem (added during assembly) which is working its way out. Wouldn't a real leak smoke all the time as engine vacume would pull in more oil?

I've heard that smoking at startup is caused by oil pooling above the valves which flows down the stems via gravity and accumulates. That doesn't mean oil doesn't keep flowing down when the engine is running, but it doesn't accumulate like overnight.

[49er]

Sounds like you may have damaged your new seals when fitting them.
They should sit neatly over the guide head. By using the socket to fit them and hammered them down you may have crushed the top sealing surfaces. They could be slightly oval and allowing oil to pass into the valve head area when the motor is stationary. Did you check the wear on the valve guides and valve stems? Any excessive wear there could also contribute to the blue smoke on startups.

[nert]

Valve stem seals leak (blue smoke) moslty under high vacuum conditions, that is on deceleration, and idle, NOT acceleration. That is because vacuum is high carb is closed, piston retreat creates low pressure on the valve stem areas sucking in lubricating oil.

A properly fit valve stem seal should be a pressure fit (light hammer) to the guide. It should fit tightly to the valve stem. Damage can be incurred during assembly, if the spring and retainer is compressed too greatly, damaging the seal beneath.

The oil will produce witness marks on your spark plugs. Run the engine for a bit while smoking. (not you, its bad for your health too) Shut the engine off. Mark each spark plug with a pencil mark at 6:00 oclock. Remove the spark plugs, and see what portion of the insulator is more darkenend. hold the pencil mark at 6:00 as a reference. Note the darkened part of the insulator. If its pointing towards the carb, then bad intake seals, toward the exhaust, than bad exhaust seals, pointing downward, bad rings. check each plug, to determine which cylinders and what source of oil entry.

sometimes, you may have to put miles on the plugs to see results. Just because the smoke stops doesn't mean the oil isn't still burning.

[DimitriT]

Sounds like you may have damaged your new seals when fitting them.

I don't doubt it. What's the right way to fit the seals.

I didn't have the right tool to do a precise measurement but the guides had no wobble that I could see. The valves appeared to be firm in the guides with no lateral motion.

[SkeletonLake]

I would discount bad valve seals, it would stand to reason if they were damaged it should smoke all the time. How many miles on the engine? Agree that oil is likely running down the valve guides. If you did damage the seals, and I have, take it to a machine shop; they will do it in minutes (isn't experience a great teacher?).

[blo]

Hi DimitriT!
If I remember correctly the vesra set included some small plastic "condoms" to put over the valve stems to prevent scoring when reinstalling the valves/seals

It is possible that the notch in the valve stem had some rough edges which damaged the seals.

[DimitriT]

Hi DimitriT!
If I remember correctly the vesra set included some small plastic "condoms" to put over the valve stems to prevent scoring when reinstalling the valves/seals

It is possible that the notch in the valve stem had some rough edges which damaged the seals.

Didn't find the comdoms in the gasket set I purchased. The notch is exactly what I'm think may have done it. Either that or I was too rough with the fit or I depressed the spring too far and squeezed em.

Does a machine shop have the ability to compress the springs and change the seals without removing the head? Some sort of giant C clamp? If that's the case, I'll try to identify the bad seals get the OEM seals and take it to shop for them to replace the bad ones.