thirdchildhood

iTrader: (6)

Based on my personal experience. Life of Bravo 1X behind 525: 7 hours (upper gears broke). XR upper: 3 seasons before the input shaft bearing pre-load nut loosened and took out the upper. Second XR upper with bearing pre-load hard shimmed: going on second season. Bravo 1 & 1X both use the spiral gears which are not as strong. I believe they are only cut that way to reduce noise. Both of my XRs were (are) old style which some people say had stronger upper gears than the swept back uppers.

Keith Atlanta

I am going to take a picture of my XR junkyard for you: (keep in mind, I have stellings boxes so there is no damper and I am at 640 HP in an 8500lb boat)
2 straightback XR uppers spit teeth (one of the two would never hold so I think the case was tweaked)
1 sweptback XR spit teeth
1 sweptback X spit teeth

Now, I have a an XR straightback on the boat that has 40 hours and metal on the magnet. I have a sweptback X at the shop that has teeth that are looking pretty pitted but it got me home. I also have 2 used X sweptbacks that are in great shape that are my next candidates for Amsoil 140 severe gear. They are my next victims.

My latest theory is to buy used and beat the crap out of it...

thirdchildhood

iTrader: (6)

The Bravo in any form is definitely a weak link. The upper gears are too small no matter how they're cut. In my application of a single 525 in a 22' boat with top speed of 83-85 the XR seems up to the task. Like I said, I'm on my third Bravo upper so I am not a Bravo cheerleader. I do feel that the XR is quite a bit stronger than the X. The good thing is that you can still find brand new uppers cheap if you shop around but you'd better make sure that the input pre-load nut is hard shimmed or loc-tited in place!