# 09 brute 750 power loss (not fuel pump)



## brute21 (Mar 12, 2010)

Guys I have a buddy with an 09 brute that is having problems running right. First thing we tried was replacing his fuel pump but it didnt work. The guy at the shop said it could be a rod but he has never sunk nor run hot. What else would you guys try? He has a snorkel, full exhaust pipe, radiator relocated.... but has never had a problem and it finally started acting up on him. We changed batteries just to knock that out too.


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## Astaelan (Jul 24, 2011)

Well, what do you mean by "not running right"? There isn't much for details to work on here. With snorkel and aftermarket exhaust, it could be as simple as running too lean or too rich. What happens if you partially cover the intake snork?
Have you checked plugs? Make sure it's arcing a proper spark to the terminal, clean'em up if need be. How is your air filter, is it clean? Did you use some filter cleaner?
How old is the exhaust, does it need repacking?
Sadly, the 2 things you've tried, are lower down on my list to replace without a lot more troubleshooting. Was the battery unable to turn over the ignition? Was the fuel pump tested prior to replacement? Maybe these were fine.
It's an 09 750, means it's fuel injected right? just realized that, I've seen a number of issues with the fuel injected machines... most people refer to the 750's as having a glass jaw, they break pretty easily, and most commonly I'm seeing it's fuel injection problems (go figure, old carburated car works fine, but fuel injected always gives me problems). What about an EFI, is it running stock CDI? More details man!

Edit: Obviously you've checked oil level, yes? If you ran it dry on oil, or you have a bad rear seal, you could have screwed the rod by running dry, or getting water up into the seal. You don't have to sink it to get water into a bad rear seal.


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## filthyredneck (Feb 10, 2010)

X2.... Need more info. Sounds almost as though it could even be limp mode lol.


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## wyo58 (May 13, 2011)

filthyredneck said:


> X2.... Need more info. Sounds almost as though it could even be limp mode lol.


It does sound like the limp mode to me too.


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## brute21 (Mar 12, 2010)

my bad guys... it will crank up fine idle fine but when she gets hot and you give her throttle she is sluggish and will go dead instantly when let off. She would not crank up with his old battery because it was soo dead which is why we put a new one on it to see if it helped. He said this all started when the battery was loosing charge. He hasnt checked his plugs because it is sparking fine or it wouldnt run at all. I personally think its running lean but it cant be cause he rode it a while like it is and it ran fine. It just all of a sudden lost power! Its not in limp mode because 1 the light is not on and 2. I know exactly how they act in limp mode and she is just acting realllyyyy sick right now.


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## wyo58 (May 13, 2011)

Why is it loosing battery charge? when it's running what voltage do you have across the battery terminals?


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## hp488 (Sep 23, 2009)

I think it should be about 13- 13.9


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## Astaelan (Jul 24, 2011)

> He hasnt checked his plugs because it is sparking fine or it wouldnt run at all


Generally true, let's assume for the moment they are okay. To run proper at idle, and bog out when you give it throttle, it could be the fuel injectors, they might be dirty or have something stuck in them, enough fuel for idle but nothing more. Also check your air filter.
As far as not keeping charge on battery, there has been a few different problems there, anything from a short, to feedback. Is there a winch on this machine? Just recently someone had some oddball parts that resulted in some odd behaviour that was killing battery with the key out of the machine (winch worked with it off too, and if I read right, was boosting the ignition allowing to run without key). Electrical can be a trouble to track problems down with, but as mentioned, check your terminal voltage, also check the voltage at the fuel pump, make sure it's getting enough power.

Also, will the old battery still recharge if it's taken out and put on a charger, does it hold charge without being connected to anything? If not, then a battery replacement certainly wasn't a bad idea, but if the battery is holding charge off the machine then something is drawing power when the machine is off (could be a simple short grounding out).


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## brute for mud (Jul 15, 2010)

did you check compression i have seen low compression act like a fuel problem many times and i have stators act goofy and idle fine and not work with throttle just some of my experiences


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## wyo58 (May 13, 2011)

hp488 said:


> I think it should be about 13- 13.9


Yeah should be in this area, maybe a little higher if the battery is low. What we are getting at is the ECU's hate low voltage and do strange things when the voltage is low. Keep in mind your sensor voltages are usually half that of the 12 volts, around 5 volts. So if the operating voltage is low it effects the sensor voltage even more.


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