I have a Honda CT-110 1984:
It's a 6 volt system, the resting is 10 volts when I start it , it's 8 volts or so and when I rev it, it 9.5 or so will the high voltage hurt anything? If so what can I do to lower the voltage? Anyone have any ideas?

Nah. That's the way it was designed. The output (little alternator coil) has to have a higher output voltage
than the battery or it couldn't re-charge the battery.

Put that volt meter on your truck battery while the engine is running. Same thing. Meter will read 15+ volts or so.
Then you turn engine off and the meter will read 12.5 volts.

A good hot battery is easier on your electrical system than one that's undercharged.

Well just checking, it seems to blow bulbs alot and I was thinking it was the voltage. But it's not difficult to switch bulbs.

All small engines with battery charging coils are pretty much the same.
Boat motors, 4 wheelers, motor cycles, lawn tractors etc.
Instead of having a true voltage regulator assembly they depend on diodes to limit the rectified voltage to the system. I guess it's possible to have a diode go bad and not limit voltage. Usually when a diode goes bad it just open up and doesn't pass any voltage at all.

You got a repair book on the bike?

No repair book , are there any in line voltage regulator or reducer that I can put in line near the bulbs?

I've never heard of such.

Honda 90 or 110s were good little bikes. I've read the same basic model is still sold overseas.
They're what you see in pics of the Philippines or Vietnam. where some guy is hauling his wife, two kids and maybe a hog or a crate of chickens tied on the side going down the road.

You already own and know how to read a volt meter so you're on the right track. Why don't you send off and buy a repair manual for the bike. That'll tell you what you want to know of the bikes electrical system. 20 or 30 bucks for the book and cheaper than any ad hoc voltage reducer you could come up with. Clymer and Seloc brand manuals are a couple. Look on Amazon, might find one used for cheap.

I think I've run across a internet forum just for those Honda 90/110s. They have a cult following like the old Toyota pickups do.

If you're only worried about the bulbs, try and find LED bulbs. They are much more forgiving on voltages.

Call Wolfie. He seems handy.

What bulbs does it blow, turn signals or head and taillight ? 10v resting is too high for a 6v battery. A good fully charged 6v should sit at 6.3 or slightly higher. While the bike is running and charging it should be about 7.5v not much higher. That honda should have a charging coil and a lightning coil , it uses the battery as the regulator. Check and clean your grounds, but from how you describe it it sounds like your charging coil is bad and now possibly your battery from the over charging.

Thanks for all the suggestions, I'm going to try a new battery lead/acid and go from there.