Re: 600+hp with a XR Drive??
 

Not really. He found out the motor was built half ass! Stock connecting rods dont hold up after 200hrs. on 525hp. Other than that happening this yr. the past have been good running! :D

Re: 600+hp with a XR Drive??
 

I have an XR upper and a IMCO lower with 800 hp on a 26 ft cat going on 3 years no problems ... knock on wood... I wouldnt say im all that easy on it either.

Re: 600+hp with a XR Drive??
 

When you guys are breaking drives, what actually is breaking? Shafts? Gears? Bearings? Don't know?

Re: 600+hp with a XR Drive??
 

RJBBC,

I wouldn't let my experience be any kind of deterant. As I said, I got the drive used. I am 100% positive that the shaft had a crack in it from when I got the drive. I am confident the drive will last for a while now.

Re: 600+hp with a XR Drive??
 

ECeptor,

What I have seen in the past couple of years is dependant on the model of drive and where it's weak points lie.
The older standard Bravo's used to push the floor of the gear out. The new X gears with thicker floors stopped that problem.
I see 25-28' boats with blowers eat teeth off the pinion gears or driven gears, thats when I recommend the step up to an XR.. If you break teeth, move up. If your not breaking teeth then an uprade to the X gears is a good move. The next week link will be the tower in the standard Bravo. When ever a standard Bravo breaks teeth, I have seen the tower egg shape. I have been installing my own steel towers to prevent that but when the old tower is milled off there can be cracks down below.
On the XR's on heavy boats (11k - 16K) The weak link seems to be the vertical shaft in the lower, I replace that with the Imco piece that was upgraded about a year ago. I have not had the opportunity to do that for one of the heavy boats yet. But I have seen plenty of the stock XR shafts break.
In the lighter boats with heavy power the XR gears will wear out early. Typical use seems to be 200-250 hrs. Extreme use, 60-70hrs. I have one drive I built on a 25 H2x with 966hp that runs over a 100mph and the guy drag races it constantly with a 32" prop. It is very fast on acceleration. He had some motor problems and while it was being looked at, I did an inspection of the drive. The upper gears were worn out, but every thing else seems to be ok.. I will be working on that today and will see if there is anything else that took it's toll while being run so hard.
A lot has to do with setup. Just proper setup on a 50' boat I was servicing increased XR life from 20hrs to 80hrs. But I was never allowed to build one like I did for the 25' H2x.. A lot has to do with the way you drive your boat and what kind of water you run in...
I have rambled enough.. I hope this gives you some insight.. I would be happy to answer any questions and share my experiences..

Dick