# Brute 650i loss of power and rear brake failure.



## vtfast (Feb 19, 2009)

2006 Brute Force 650i chipped with carb tuned.
HELP! Riding last week around 50 mph a haze of oil came up out of the handle bar area and I suddenly lost power. The air box had no oil in it but the clutch was hazed with oil. The vent tubes under the handle bar cover was hazed with oil as well. The oil was engine oil and the dip stick showed just a slight oil loss, nothing to be worried about. 
After cleaning all I then test rode the bike with marginal improvement but now the rear brake has bottomend out and I have no adjustment left.
The engine seems to run good. Prior to all this happening I replaced the belt and cleaned the carbs. I put about 30 miles on the Brute before this all happened. 
Anybody have any ideas were I might start looking? I think I may have two 
problems happening but I am not sure.
Thanks for any help you all may be able to give me in advance.


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## cajun mud mafia (Jan 25, 2012)

if you do aggresive mud rideing you may have to completly take off your foot break. it will lock up and just build preasure in the lines till they pop. not sure if thats the problem you are having though. hard to tell.


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## vtfast (Feb 19, 2009)

Pressure in which lines? The rear brake is cable operated. Are you talking about the vent line? Thanks.


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## Polaris425 (Dec 16, 2004)

Tell me about your snorkels, what all do you have snorked??

IF you have your crank case breather cut off from the box, and run up under the bars, oil could have shot out of the breather, which is why it wouldnt be in your air box...
This would happen especially if you had been doin wheelies and hard stabs of the throttle.

If not, then the only vent lines there that oil could come from, would be diffs... 

But since you say you lost all power and the clutch had oil all over it, if you mean the inside of the clutch then you could have blown the seal that's in there, and the oil came out of your snorks???

It's hard to tell where it came from w/o a little more info on what all you have snorked & what vent lines are run up other than factory. 

Also, I dont think your brake faliure has anything to do with the oil.


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## vtfast (Feb 19, 2009)

No snorkels on the bike, all stock intake and exhaust on the drive and air box. I suppose I will have to pull the clutch's to see if I have a blown seal. The vent has not been cut, still n the stock routing position. Other than the Moose chip and carb tuning, it is a stock machine.


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## vtfast (Feb 19, 2009)

Kinda figured the brake issue is something else as well, going to disassemble the brake and take a look. Which seal would you most likely suspect, the crank or the trans?


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## Polaris425 (Dec 16, 2004)

Hard to say really. I'm trying to think where oil could have come from, under the bars.. the only vents that are there that I know of that oil could shoot out of would be diff vents... 

Unless one of them is the transmission vent, which would make sense, if the seal went out, that could be why there was oil on the clutch, and some shot out the vent.


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## vtfast (Feb 19, 2009)

I'm headed out to drain the rear diff and take a look at it and also look at the clutch again and see if any new oil is in there, more later.


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## vtfast (Feb 19, 2009)

They are not listed as transmission vents in the 650i service manual, I will post with more info later.


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## vtfast (Feb 19, 2009)

Engine has 70 psi in front and rear cylinders, new plugs and adjusted the valves. Them front exhaust valves are a bugger to adjust! Reinspected the clutch with nothing abnormal. Engine seems to run really good. Now on to the differential......

The diff oil was burnt and black! Changed the oil and adjusted the brake again. Went for a ride up and down the Georgia red dirt roads and around the property and low and behold the infamous haze of oil returned! Rear diff oil blistering hot that it burned my legs... Felt the diff and you could cook a steak on it. Looks like I have found the problem. Will be disassembling the diff tomorrow to see what's inside. Maybe I will take pics along the way if anybody is interested. 

Anybody heard of this happening? I think it is a brake failure of some sort. Hoe it didn't cause any diff problems as well, nothing is easy with these things...


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## Polaris425 (Dec 16, 2004)

Weird. I was thinking it had to be diff oil shooting out.


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## Eastexasmudder (Nov 21, 2011)

That's a new one on me?!? 


I'd rather be riding instead I'm using tapatalk!


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## KMKjr (Jan 9, 2009)

I'd be guessing the brake is sticking on, overheating the fluid and boiling it out the vent.


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## Polaris425 (Dec 16, 2004)

KMKjr said:


> I'd be guessing the brake is sticking on, overheating the fluid and boiling it out the vent.


That's a good guess. :agreed:


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## KMKjr (Jan 9, 2009)

Polaris425 said:


> That's a good guess. :agreed:


Right some smart I is!!


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## DaveMK1 (Nov 8, 2009)

think he would of felt the brake dragging?

Sent from my droid when I should be working. MIMB RULES!


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## vtfast (Feb 19, 2009)

Something to think about.... The pinion gear forward bearing retainer backed off causing the pinion to drive forward applying pressure to the brake, the faster you go the more pressure is applied to the brake. It also destroyed the forward pinion shaft support bearing. There is 3 bearings total on the pinion, the forward bearing acting as a support bearing for the input shaft and brake loads, the other 2 being for the actual pinion bearings, the retainer nut for the bearing I am referring to is the actual forward pinion bearing. The retainer is supposed to have locktite on it but guess what, this came from the factory with no locktite applied. Weird. Everything else had locktite on it were it was supposed to be.

I could probably reuse the bearings but with the stress applied to all I will be replacing all bearings, seals and of course a new brake stack. 

I would suggest to 650i owners that may have their diffs out for other maintenance to inspect the retainer since it is easy to get at and inspect since it is out on the bench anyway. An ounce of prevention can save $300 dollars worth of repairs!


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## vtfast (Feb 19, 2009)

One more thing, all this damage was caused in less than 20 minutes of riding between the time the problem arose and it was found so the answer to your question if you thought I felt the brake dragging is obviously YES, that's why all the trouble shooting was going on.


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