Probably too tight, rarely do i see a loose belt snap. they should be looser than you think they should be. too tight = more heat and friction as well as higher power consumption. i've never had a belt snap on me but i've seen it happen. if you see black dust around your pulleys or guides, that's another easy way to tell it's too tight. jeff west of westhobbies rc has a good video on belt tension if you need any visual on how it should be.

I have watched Jeff West's video on the belt tension but didn't get the chance to try it before the tail belt break. Thanks so much for your help!

Normally if you have a belt break it’s because it’s to tight. Personally the only time I ever spray or use silicone oil (3:1 silicone oil works great) is if I’m having a static issue. I’ve got tail belts with hundreds of flights and belt was never touched with oil.

​@@westhobbiesrc8051plus one. In all my time flying helis the only time I used a belt dressing was on a Msh Protos to help eliminate static. I've never broke a belt dry under normal use. Having said that I'm sure dressing them is just fine but from what I hear, once you start you have to keep it up

WD40---> "Silicone Quick drying" version is what i use. I dont think anyone should be using WD40 original on a belt. I did make mention of this info in the video. However I've used many versions of silicone spray in the past and never had an issue with any of them. Food grade or not...

@@hermanquinones yea, but still contains solvents in it that who knows their long term effects (talking 4-5 years at least) on the tail belt. At least with pure silicone shock oil, you definitely know what you are putting on it and that it won't react negatively in the long term. I mean, lubing the belt in the first place is to increase the life of the belt, why do questionable stuff that can compromise it? Also, with pure silicone shock oil you can get different weights of oil, so you can even optimize performance there too.

@@stuffD-fh8vfnot sure if you are talking about other sprays. But according to the wd40 silicone spray composition information sheet… the only solvent is the one used to carry the silicone spray which is LVP and immediately evaporates. That said, you are right. It’s something to consider for those using other types of sprays and not cross-referencing the info sheet. Also… maintenance should still be done and that includes but not limited to belt replacement.