Topic: CB175 valve stem seals. Advice on replacement?

[fmctm1sw]

I got to looking at my 175 head and the degree of difficultly appears much greater than that of my 350Fs.  I know how to get the camshaft out of it but the head being the way it is leaves the valves seemingly way down inside the head.  Does anyone have some guidance before I just start tearing into it?

[tbpmusic]

I got to looking at my 175 head and the degree of difficultly appears much greater than that of my 350Fs.  I know how to get the camshaft out of it but the head being the way it is leaves the valves seemingly way down inside the head.  Does anyone have some guidance before I just start tearing into it?

Getting the valve springs off is pretty simple, you can just put a suitably sized socket on top of the springs and give it a whack - the retainers will pop right out. you may want to plug the top of the socket (square hole) with a kleenex, or the retainers may sail across the garage. If your shop looks anything like mine you'll never see them again.....

To get them back in you really need a valve spring tool - looks sort of like a big c-clamp with special tips.

[fmctm1sw]

The seal I was referring to is in the picture (#9).  Even with the cam removed, the valves on this bike are way down in the head.  I'll try to get a picture....

[tbpmusic]

OK, I got you - my bad, that's the valve guide seal alright.

Yeah, they're down in there, but they'll come out like I described.....

[tbpmusic]

Here's a pic of the tool you need to get it all back together.

[bryanj]

Once the valve is out they slide off and on faily easily, destroying them getting them off if they are hard don't really matter as you are fitting new anyway!!

Hard part is finding small enough fingers to get all the bits back together

[Sam Green Racing]

To get the keepers out once the spring is compressed, I use a very small screwdriver that has been magnetised.

Sam.

[fmctm1sw]

I got my head back from the shop and finally got to this.  I fashioned a tool to get the springs out and was presented with this.  After looking at the parts fische I guess what I think is the top of the valve guide is actually a cap of sorts.  I hope because that stem seal is nowhere to be found at this point.  I'll find out tomorrow...

[Bodi]

There's no seal in your photo, that is the valve guide. The seal just snaps onto the groove.
You can run OK without seals, it will burn a bit of oil that leaks down through the clearance between valve and guide. Many engines don't have seals on the exhaust valves, but the intakes are subjected to engine vacuum and will draw oil down so these should have good seals. Worn intake guides and bad seals will allow a fair bit of oil to enter the cylinder... you get blue smoke especially after engine braking

[fmctm1sw]

I didn't see any way to get those seals on.  They would have just been flopping around in there.  I got it all back together and had it running last night.  One of the carbs had a clogged idle jet too, I may seal the tank.

[mystic_1]

That guide is the same as the exhaust guides on early 750's - they had no seals.

mystic_1

[fmctm1sw]

Trouble is, that was an intake valve.  I got it all back together now and have it running.  We'll see what happens...