F-ing Valve seal.

[Willson]

So: I check the valves are sealing on my cylinder head, and have one very slightly leaky valve. I'm told (by a mechanic) to clean them all up as I'm disturbing one of them so I do.

I now have 4 valves pissing petrol and 4 that are slightly leaky.

Now I've got to lap all 8 valves again, is there an easier way of getting the split collets at the top of the valve stem to stay when I'm refitting the valves? Or is it always a pain in the arse?

Thanks in advance

Willson
____________________
Benson: Wouldn't life be easier if we were all turtles?
Me: Pig on bread = The way forward.
Riding: '00 Suzuki SV650S. Previous: '99 Kawasaki ER5 - sold, '02 Suzuki GZ125 Marauder - sold

[finpos]

Grease as temporary glue.

And lapping valves by hand takes 100x more effort than people make out.

f.

[Willson]

If the valves aren't sealing now, then when the grease wears off/is burnt off won't I have leaky valves again?
____________________
Benson: Wouldn't life be easier if we were all turtles?
Me: Pig on bread = The way forward.
Riding: '00 Suzuki SV650S. Previous: '99 Kawasaki ER5 - sold, '02 Suzuki GZ125 Marauder - sold

[Rockhopper]

You only use the grease as a temporary glue to hold the collets in place while you get the compressor off.
When you grind the valves in you should get an unbroken mid grey ring around the valve seat. Don't forget to wash all the grinding paste off after though.

[Vincent]

I think finpos means that you can use grease to hold the collets in place while you replace the vsalves.

Are you 100% sure that you lapped the valves correctly?

ie; left and right rotation and up and down? Turning the valve by 90 degerees after each spin? Starting with coarse paste and working your way down to finest?

[Rockhopper]

Of course if the seats are really bad you may need to get them recut.

[Willson]

Sorry my bad, I was being a retard...

The old man showed me how to do it, and I followed his instructions.

I think it's just a case of me being an utter retard and doing something wrong...

I only used the fine paste as there wasn't much in the way of leakage.

There was a mid grey ring all the way around all of the valves when I'd lapped them.
____________________
Benson: Wouldn't life be easier if we were all turtles?
Me: Pig on bread = The way forward.
Riding: '00 Suzuki SV650S. Previous: '99 Kawasaki ER5 - sold, '02 Suzuki GZ125 Marauder - sold

[Rockhopper]

Can't have been otherwise you wouldn't have a leak

[stinkwheel]

I usually fit the collets using a pair of tweezers. There is a magic distance to have the spring compressed where they will drop into place but not fall through. Back off the tensioner on the spring compressor a bit at a time until you reach this point. You often need to gently push it over to one side then the other to get them both in

Bench mounted, lever action spring compressors are much better for doing this because you can ease off the pressure you're putting on the spring as you insert the collets. Not so common to have though.

If there is a grey ring all round the valve, they should seal. Is there any pitting on the seat?

EDIT: I was also taught to give the end of each valve a good sharp tap with a hammer after the collets are fitted to make sure everything is seated properly.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.