Valve cover gasket sealants

[HBFL]

First time valve insp/adj. on this 99 I/S as new owner at 70,000 mi.  V/C Gaskets appear ok no seeps, weeps, or leaks prior to removal. Not hardened or cracked. Wanted to replace anyway, no idea of their age, but cant get new ones prior to my trip. Next time.

So I get the RTV on the 4 points, but what is the sealant in the valve cover groove? Manual says three bond 1521 or equivalent. It appears to be very thinly applied. Is it necessary?

Thanks in advance.

[SCain]

The Three Bond 1521 is a Synthetic Rubber Sealant (fancy name for RTV????). Never heard of it, I have always used either Honda Bond or Yama Bond on the 4 corners and thats it.
I think you can but the equal to honda bond at auto zone, this is a grey gasket maker in a tube, stays plyable but seals great.

[Bob D]

I just did mine with the three bond sealant. The only reason to put a thin layer in the groove is to hold the gasket in place while you install it. My new gaskets out of the package from Honda we’re a bit folded and wouldn’t lay flat in the groove without the sealant holding them in place. I used a bit too much and it squeezed out a bit as I snugged the valve cover up. Use sparingly....A little dab’ll do ya!

[Chrisj CMA]

That gasket is designed to seal without sealant. I have done many valve adjustments and have never used sealant (except for the four landings) and no bike I worked on had any evidence of sealant.

[RonW]

Just keep an eye on the bottom rung of the gasket. If it shifts on you, it misaligns.