Valve Seals

Has anybody tried to replace the valve seals without removing the cylinder heads? I would say mine are shot, was thinking of replacing them with the old air compressor in the spark plug hole trick… Just wondering if anyone has tried it that way and how it went for them.

I haven’t tried it personally, but another old bushie method I have heard was to rotate the engine so that the piston is rising on the compression stroke, valves closed then insert thin rope (nylon would be better)into the cylinder through the spark plug hole until you have enough to compress it and prevent the motor turning over.
Then you can remove the valve spring without fear of losing air pressure.
Then the only question left is, do you have enough clearance to actually remove the valve spring?

I heard about the rope trick as well. I can’t see clearance being a problem to remove the springs, the stem seals are the last thing left on the VF1000f and she’ll be done. Took her for a few runs already and she works and handles better than before the crash. I’m attributing that to the complete fork rebuild and new bearings… Just picked up another project for the winter though, an 86 GPZ900R… She’ll Keep me busy this winter for sure…

hi windex, it sounds good in theory, but having done the valve seals on a couple of vf engines recently (with the heads off) i can only imagine its going to be extremely fiddly compressing the valve spring far enough down then holding it in position while you fit the collets in place, and with limited access working round the frame tubes… :o :o
I don’t think it would be something i would attempt, i can just imagine lots of swearing, blooded knuckles and valve springs flying all over the garage…

i have done it on my XR with great success but like Pete said , clearances between frames etc. you could try to modify a spring compressor to bolt onto where the top cam chain guide bolts to and hopefully be able to get to all the valves.