Replace the valve seal? Yes. The guides too?

[Guest]

Hey GSR.

Winter maintenance being done. It's snowing outside right now so this is very appropriate.

I have installed my hand-wound stator and it test great.

Now to do the other things. Not because they are easy but because they need doing.

My bike is a 1983 GS1100GK.

I will be doing the usual oil changes, valves adjustment, carb balancing, etc....

Now what is new to me is getting down to my valves.

My bike as developed a serious smoke after sitting problem. So I am going for those valve seals.
I am just about to order parts and I am getting the jitters, hum and what-ifs qualms.

My bike as over 120,000 km on it should I pull the valve guides?
How do I test them? Compression?
Do they just pull out? I can't find info on how they stay in their place. Are they just seated and held in place by the springs?

I was planning on doing the work with the engine on the bike and the cylinders in place. That works for valve seals. Does it for the guides too?

Any comments welcomed,

Thanks,

Daniel

[Nessism]

A few things, first, any time you pull the head you should also pull the cylinder otherwise you are very likely to have base gasket leaking issues.

Secondly, the service manual specifies how to perform the "wobble test" which determines the condition of the valve guides and to some extent the valves themselves. Check that and you will know if you need new guides.

Typically if you need new guides it's time for a rebore and new pistons too. If the bores are still good some new rings are a good idea when the head is being refreshed. You should have the bores and pistons measured to determine this too.

Good luck

[Guest]

A few things, first, any time you pull the head you should also pull the cylinder otherwise you are very likely to have base gasket leaking issues.

Secondly, the service manual specifies how to perform the "wobble test" which determines the condition of the valve guides and to some extent the valves themselves. Check that and you will know if you need new guides.

Typically if you need new guides it's time for a rebore and new pistons too. If the bores are still good some new rings are a good idea when the head is being refreshed. You should have the bores and pistons measured to determine this too.

Good luck

Hi Nessism, Ed.

Thanks for the reply.

At this time I have no intention on pulling the head off. The cover, yes.
I have seen and read enough to know I can get away with the changing the seals without removing the head.

From your reply. I am guessing that to pull the guides the head has to be off? Push them from bellow?
Also from your reply, if they are shot so are the pistons. If I reverse that. The pistons are good so...The guides are good.
The compression is good and the bike pulls more than I can handle.

If that is the case you just saved me work and money.

I like my GK but I have no intent to redo the whole engine.
Keep it for a few more years then I will change it for smaller. Not getting any younger and stronger. And the bike will not pickup any value either.

Wobble test...I am guessing that is done with the head off. Off to look in the book then.

Daniel

[Nessism]

Hi Daniel,
If you can change the valve stem seals with the head still on the bike you will the second person to accomplish such a feat (that I know about) during the years I've been here. I wish you all the best. It CAN be done, but not without some fiddling and fabrication of some custom tools. Please post up some photos when you get busy so we all can learn.

Good luck.

[Steve]

The actual changing of the seals will be rather easy, compared to compressing the valve springs so you can move them out of the way to get to the seals.

Yes, please do take a LOT of pictures so you can write up a tutorial for the rest of us.

I will be pulling the cylinders anyway, as there is a bit of leakage at the base, so I won't need your tutorial this time around.

.

[sharpy]

one motto should be in use here. Do it right the 1st time or not at all.

[tkent02]

From your reply. I am guessing that to pull the guides the head has to be off? Push them from bellow?
Also from your reply, if they are shot so are the pistons. If I reverse that. The pistons are good so...The guides are good.
The compression is good and the bike pulls more than I can handle.

Valve guides on the eight valve engines and others with a similar valve and cam arrangement don't wear much under normal conditions, especially on the big bikes like GKs that are mostly used for gentle cruising. All of the forces acting on the valves are in a straight line, there's nothing to cause wear. Even on the 550s which mostly get redlined every time they are ridden they easily go 100,000 miles and more and the guides are fine. I've never had to replace one.

If you did replace the guides there is some machining involved so yes the head has to come off.

[Guest]

Hi Daniel,
If you can change the valve stem seals with the head still on the bike you will the second person to accomplish such a feat (that I know about) during the years I've been here. I wish you all the best. It CAN be done, but not without some fiddling and fabrication of some custom tools. Please post up some photos when you get busy so we all can learn.

Good luck.

Thanks. Can do. I don't hang around the GSR so much anymore but I am sure more than that have done it.

The actual changing of the seals will be rather easy, compared to compressing the valve springs so you can move them out of the way to get to the seals.

Yes, please do take a LOT of pictures so you can write up a tutorial for the rest of us.

I will be pulling the cylinders anyway, as there is a bit of leakage at the base, so I won't need your tutorial this time around.

.

I will use the air-compressor/rope trick and make a spring-compressor. Done worse. I don't think you need any tutorial from me.
It will be based on bwringer 's http://www.thegsresources.com/_forum...mpressor/page3

I removed and replaced the valve stem seals on my KLR650 (same shim-over-bucket setup as a GS) with an air hold and this home made compressor device.

I used 40 psi to hold the valve up once I had the keepers off, and increased it to 60 psi while I was actually working on the valve. No scientific reason -- this just felt right. YMMV -- GS valves are a bit smaller, so you may want to use a bit more pressure.

I also put the piston at TDC so the valve wouldn't drop all the way out if I lost air pressure. I made sure to secure the crank VERY well so the engine couldn't rotate with the air pressure. You'd want to do the same with a GS; set it to TDC, do those cylinders (1 and 4), then rotate 180 degrees and do the others. Fortunately, a GS is easy to re-time when you rotate the engine with the camshafts out.

The angled bit with the hole bolts to one of the cam cap holes. To move from the intakes to the exhausts, I reversed the fittings on the lever.

I thought I would just use the PVC to get the shape right then re-create it with metal tubing, but as it turned out the PVC held up just fine.

I'm pretty sure something similar would work with a GS. It was a tight fit on the KLR, but it worked. Pulling the old valve stem seals was the hard part, since there was so little vertical clearance to get my puller (a modified pair of large needlenose pliers) in there.

bwringer mention vertical clearance. I will see when I get there.
The head cover can come off so there has to be a few inches (A few multiples of 2.5 cm).

Valve guides on the eight valve engines and others with a similar valve and cam arrangement don't wear much under normal conditions, especially on the big bikes like GKs that are mostly used for gentle cruising. All of the forces acting on the valves are in a straight line, there's nothing to cause wear. Even on the 550s which mostly get redlined every time they are ridden they easily go 100,000 miles and more and the guides are fine. I've never had to replace one.

If you did replace the guides there is some machining involved so yes the head has to come off.

Thank you. That's exactly what I wanted to hear.

Just the seals ma'am. Just the seals.

Followed by a valve adjustment of course. It's due. Not much mileage but it's been 2 years.


Daniel

[tkent02]

Just the seals ma'am. Just the seals.

Followed by a valve adjustment of course. It's due. Not much mileage but it's been 2 years.


Daniel

Time doesn't matter on valve clearances, its strictly a wear thing. If it was done correctly a few years ago theres no reason to do it again unless there are some miles put on since then.