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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Zipster on April 27, 2014, 07:10:03 PM
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Looks like I may need to replace the valve stem oil seals soon - my K1100LT is using some oil and getting a bit smoky even when warm. The bike has just turned 97,000 miles.
Anyone any experience of doing this or have any tips to pass on?
Any idea of a guide price for getting it done by a mechanic?
Thanks,
Al
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It's not too hard, you have to get the valve springs off, which requires the head to be removed. It can be done with the engine in the frame. The 4 valve engine will require a bit more work, and smaller spaces than the two valve. You will need some special equipment, namely a valve spring compressor. You can make one with a large C clamp and an old deep socket.
Getting it done by a mechanic will be expensive. A good option would be to take the head off yourself, and bring/send it to a shop to do the work. They can replace/grind the valves or guides as needed as well.
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Thanks for that. I had thought about taking the head off or maybe even sourcing a spare!
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Smoking on acceleration or decell?
The first would be rings and the second is normally valve seals (Unless I am mistaken and would happily be corrected if I'm wrong.)
That said, I don't think I've ever heard of a brick needing rings.
Pulling the cams and buckets shouldn't really be difficult. Depending on when it was last done, I'd spring for new gaskets, half moon seals and cover rubbers too.
tg
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Smoking on acceleration or decell?
The first would be rings and the second is normally valve seals (Unless I am mistaken and would happily be corrected if I'm wrong.)
That said, I don't think I've ever heard of a brick needing rings.
Pulling the cams and buckets shouldn't really be difficult. Depending on when it was last done, I'd spring for new gaskets, half moon seals and cover rubbers too.
tg
I was going to mention that as well. Deceleration from closed throttle pulls a vacuum in the port, sucking oil through the valve guide and seal. Both of those wear out at high mileage. It can also pull oil through the rings, but the valve seals are more common, and make more smoke usually.
Is the smoke blue, white, or black? Oil use is normal on a K. Before you do a big job, lets make sure we're solving the right problem.
Bricks can wear out their rings, they are sacrificial to protect the nikasil. When I did a post-mortem on my K75 with ~100k miles (maybe more, not sure how accurate the ODO was, or if it was replaced under warrantee), there was definitely piston/cylinder wall clearance, and the rings seemed somewhat worn. I didn't measure them, but there did appear to be excessive gap. I could feel a slight ridge on the cylinder wall. There was less than ideal maintenance on the bike prior to my ownership, and I did a lot of hard miles (4000 heavily loaded, high speed) with a stuck open thermostat that I didn't discover until I was looking at data logs on the megasquirt. Lower temperature running does extra wear on cylinder walls, engines are clearanced for their proper operating temperature.
This is my DIY spring compressor. The foot of the clamp has a rag placed over it, and it is placed into the combustion chamber with the foot on the valve. The socket, with the access slot cut into it, is pressed down on the spring retainer, and the valve keepers are exposed and removed. Then the pressure is released. Reassembly is the reverse of disassembly. This is the trickiest part of the whole job, there is a real trick to getting the keepers in right, especially on the smaller 4v engines. After removing the springs and valves, you pull the seals off with pliers (they make special ones too, not always needed), and install the new ones. The new ones should be soaked in oil, and placed over the valve stem, and guided down. Then tap them into place with a deep socket or proper driver. You have to be careful of the valve guides while removing the old seals, and careful of the seal lips while replacing the seals. Make sure all parts go back to the proper position where they came from.
If you are good with mechanical stuff, it's doable, but if you are unsure, get the head off, and remove the buckets and cams (label which cylinder/valve they came from), then take it to a shop. They can probably do the whole thing in an hour or two, and they already have the proper tools.
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I didn't see the smoke myself but I smelled it and my mate who was behind me saw it. He's a mechanic by trade and was the one who suggested it may be the valve stem oil seals. I don't think he fancies doing the job though.
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Hello,
Years ago I was able to replace the valve stem seals on a V8 car engine w/o removing the heads by using compressed air to keep the valves closed and jury-rigged valve spring compressing tool. Is it possible to replace the valve stem seals on a 16V K1100 w/o removing the head?
Regards,
Richard in Commerce Township, MI
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I recon so, but is this one of those times where you go "I wish I had an 8 valve brick"
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Have you removed the camshaft cover, viewed the layout and compared it with the V8?
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I'm thinking 8V easier than V8
And 16V double the trouble.
I spose I'm going overboard by saying that because of the ridiculous lean angle of the side stand and a bit, you'd almost get away with not needing compressed air.
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Having replaced a head before, it would probably be easier in the long run to go ahead and remove the head and do the seal replacement.
Once you are that deep, removing the head is just a few bolts away.
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Having replaced a head before, it would probably be easier in the long run to go ahead and remove the head and do the seal replacement.
Once you are that deep, removing the head is just a few bolts away.
Absolutely! Been there, done that, but it wasn't where my oil was going.