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Brovo I XR drive locked up???

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Brovo I XR drive locked up???

Old 05-26-2014, 06:42 PM
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He didn't mention a high idle condition, or shifting it at a high rpm, so I did not suspect the cone was slammed into a gear. It could be a broken tooth wedged into a spot so it won't shift. Until you open it up and take a look, you really don't know. I would pull the back cap and see if anything is amiss. Detent ball could be broken preventing a shift. Viper if you do remove the back cap, remember that inorder to shift a Bravo the input shaft has to be turning. Give that a try and see if the linkage looks intact, the detent ball is not dismantled, and then you would need to bypass the neutral safety switch inorder to spin the motor over while the shifter is in gear. Not a safe thing to do, unless you fully understand how it functions, otherwise I do not recommend you do it.

Ragged,
I have several friends running B1's that have helical gears setup with steel tower in the case and top cap. Five seasons on one with 900+ hp on a 24' Enforcer. Several others at 800+ hp on small cats. These are blower motors also. I have another friend with a 38' Formula at 575hp NA that has five years on a similar pair of Bravos. 28' Checkmate with 598" NA with 4 or 5 seasons on it. I have seen XR gears last 5 hours before they spit a tooth out of a driven gear. So I tend to recommend the helical gears in a lot of situations. In other cases, the XR's are a must and you take your chances. Then I recomend the SCX.
I have on guy that wore out XR's and put XZ's on his boat and isn't having problems. So it is a case by case situation. You can't say an XZ will handle "Huge" hp on a large boat, but it may do just fine on a lighter boat. The way the boat is setup and driven plays a huge part. When new XR gears come down the pipe, then that will be the gear of choice. Til then, the helical's setup correctly, in the right situation, driven with respect, can get you farther than a broken XR gear.
Just my experience.. Thanks for listening.

Dick
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Old 05-26-2014, 07:04 PM
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I don't think I can get the motors to idle much less the way their built. It will die even out of gear if the motors running much less than 800 or 900 rpm's.
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Old 05-26-2014, 07:07 PM
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I would agree with Mr. Gadgets, I have seen some setups with b1s handle an extreme amount of hp/tq successfully with helical gears. (driving techniques are critical)
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Old 05-26-2014, 07:48 PM
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For laughs I had an xr on one side and xz on the other. 2002 year drives. The xz broke first. OK, so it wasn't that funny. Virgin drives, both labled xr, the true xr was one consecutive number lower than the xz. Merc said pound it.
On shifting at high rpm. How about an interrupt switch like used on alphas?
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Old 05-26-2014, 08:59 PM
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On the idle issue, are you sure you don't just have the idle adjusters in the metering blocks turned in too far? You could have the idle circuit running too lean, then crank up the adjuster on the linkage to get your 1200 rpms? If those bulldogs are stock you should be able to get them to idle nicely under 800 rpms all day long
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Old 05-27-2014, 06:05 AM
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Ok. I stand corrected, looks like there is a "High Idle" condition. That needs to be addressed before the Bravos can live comfortably..
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Old 05-27-2014, 08:00 AM
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Thanks for all the helpful info. I will pull the back cap off and see what is going on. The 540's are built putting out 725hp NA. I do have the idle screw down so they will run around 8 or 900, but it will die a lot when shifting at that speed. I may have to try to shift it in and then quickly give it some throttle. Would a throttle body fuel injection setup help out? It does seam really rich at low rmp. A lot of black on my transom. Read about fuel injection on this site somewhere. Thanks for the help again guys.
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Old 05-27-2014, 11:44 AM
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Mr. Gadgets, New XR gears coming down the pipe? Can you elaborate an that at all? I have heard the machining on Merc gears is crap but that no one makes aftermarkets gear sets for some reason. Although it seems like the aftermarket has an upgraded part for most everything else in a Bravo.

What are the new gears coming out, better machining? Different design? What can you tell us?
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Old 05-27-2014, 12:42 PM
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all the carbs that i have tuned the air fuel screws are out 1/2 a turn and 3/4 turn max..any more the engine will load up at idle and then will misfire until you reach like 3k rpm's..that is id the throttle blades are not turned up to high then it wont make a differance where then screws are...
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Old 05-27-2014, 03:18 PM
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Mac,
I friend has been working on a project for replacement gears, but I have no idea when that may happen. It is a long process..

Dick
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