I mounted a MiniBeast 2 on my '05 FLSTN today, well pleased with the tone and volume. Installation was easy -- hardest task was getting the horn mounting nut off (probably had not been loosened since the bike was initially assembled!). I did have a few concerns/questions:

Instructions advised to plug MB wires into stock wires, then "slide shrink wrap tubes over finished connections." Stock wires have the female connectors molded into a L-shaped plug. Should the shrink wrap tubes go all the way over those L-shaped plugs? I tried to work them down over the plugs, but couldn't get them to go that far.

Will engine heat be adequate to shrink the tubes?

Finally, instructions say to "position fused wire along frame and under the tank working your way towards the battery." As long as the wire isn't touching the head, any concern about heat?

 

You can use a lighter to shrink the tube if you don't have a heat gun.
Any auto parts store should have shrinkwrap in larger dia. if you feel you need to cover the plug also.
Dielectric grease over the connector then plug in the horn leads should be enough. Just make sure the shrinkwrap covers any exposed wires the insulation might not cover.
As long as the wire isn't touching or close to the exhaust header, the wire should be okay. I'd still run it up in the wiring channel to hide it myself.

 

Can't the shrink tubing be skipped? Stock horn doesn't have it.

 

I believe, since it's been awhile, I positioned the tubes over the connectors as far as possible and then secured them with some friction tape. If they won't fit, just use some tape. I think they're main purpose is to waterproof the connection. I then snaked the wire up and under the tank and to the battery. I taped the wire to some connector under the seat to keep it from coming lose. The horn is excellent and I haven't had any problems and my bike gives off more heat than yours 'cause I have a catalytic converter.

 

I still have mine too. Keeps me warm in the winter. lol