VF500 Valve adjust

I have an 86 VF 500 that has been sitting in the back of my garage for about 4 years un-used, though it ran when it got parked. I decided to try it get it running again which meant cleaning the carbs. Once those were off I looked ana thought it would never be easier to adjust the valves. Upon inspection, the stem on the outside exhaust valve for cylinder #4 is seriously mushroomed, and if I fiddle the adjustment close I can't even slide the feeler gauge all the way in, it appears the the top of the valve stem is below the retainer.

My question is: is it worth trying to find the proper tool for the adjusting screw, and just do the best I can? Or is this thing basically done?

 

If you ride the bike chances are weighted toward that valve dropping and ruining the engine.

 

Yes, unfortunately you have run into a known weakness of the VF500. Replacing the valve is really your only option or perhaps a second hand engine if you can find an unmolested one.

 

And possibly spitting you off the bike...

Yep, this is the only way to properly correct this somewhat common problem. Some try to run the "stem cap" mod nonsense... However, this has only had moderate success from what I've heard.

Btw, welcome to the forum dskelton.

 

Oh well. I guess I knew the answer before I asked the question. Suppose I was just hoping for a miracle cure.
My only interest in getting it running was something for my daughter to ride as her bike is in storage near school while she is home for the summer, and a major repair would probably take longer than she'll be home.

Any body want a parts bike?

BTW FMB42, thanks for the welcome, but I have been around for quite a while, just lurk a lot.