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6 Posts
Hello everyone, I'm new here but have spent a lot of time reading up on this Brute the last few days.... Seems these things have a lot of problems....
Incoming long post, I want to try to provide as much detail as I can. I will add a tldr at the end.
A good friend of mine has dropped off a 2006 Brute Force 750 at my house that was having a lot of problems with over heating, fan not working, and battery not keeping a charge. I have a chance to buy this thing for pretty darn cheap, but will only buy if I can get it running good. After some reading I learned about the rear bus and cut it out and used solder and wire nuts to connect all the correct wires. Fixed those problems, besides the fan, which I just hard wired to a switch. But then when I would ride for maybe 20-30 min, I could feel, what I thought was the engine getting really hot, and the quad would start to backfire and have complete loss of power. (Mash the throttle and it will take off really slow and not want to climb hills and such)
After more research and pulling my hair out, I read about possible exhaust leaks, which it turns out it was leaking on the rear exhaust.(only had one nut.....) I then got the exhaust tight and stopped the leak. The quad seemed to get a lot more power and of course quit burning my leg from the leaking exhaust and I was happy... for about 20-30min until the quad warmed up and it lost it's power and starting to backfire again... I pulled the plugs and noticed they were fouled up and rather black.(cleaned them up and put them back in, they seem to be in good condition, were just dirty with black soot) I read about the choke maybe being stuck and/or running too rich. I pulled off the air filter, looked down in the carb and fired up the quad. The back carb was locked up (when hitting the throttle or using the choke the thing would stay closed. I pulled the plastic cap off the rear carb, cleaned the spring and made sure the rubber gasket thing was not cracked or broken. I put it back together and fired it up, and the back carb is now working in sink with the front carb when throttling.
I again was happy thinking I have fixed the problem..... but again, my happiness only lasted for 20-30min (until it got nice and warm) and then I lost it's power and it started to backfire and sputter again. I stopped the quad and pulled the air filter off to make sure both carbs were still working and they both are.
I have read about maybe needing to adjust the pilot screws on the bottom of the carb and making sure they are both at 2-2.5 turns. I have also read about it maybe being a full pump / vacuum problem.... Before I go any further and stress myself out anymore I thought I would ask around to see if anyone knew what my problem is and what the fix is. Any help would be great!
tldr: Quad runs great when first started. After 10-30min of riding the quad will lose power (Mash the throttle and it will take off really slow and not want to climb hills and such) and start to backfire and sputter.
Side note: While I was cleaning the spring on the back carb, I noticed two "nipples" on the bottom of the carb with nothing attached to them. I also found a long hose that splits at the end into two small hoses just laying under the carb. (Long Y hose) I assume that goes on those nipples? I plugged them on and they fit snug, I then ran the end up the handle bars and poked out the front. I assume is was a vacuum or exhaust for the carbs? After doing so, I did not notice any change in how the quad was running, besides the same problems with loss of power and backfiring / sputtering after being driven for a bit.
Incoming long post, I want to try to provide as much detail as I can. I will add a tldr at the end.
A good friend of mine has dropped off a 2006 Brute Force 750 at my house that was having a lot of problems with over heating, fan not working, and battery not keeping a charge. I have a chance to buy this thing for pretty darn cheap, but will only buy if I can get it running good. After some reading I learned about the rear bus and cut it out and used solder and wire nuts to connect all the correct wires. Fixed those problems, besides the fan, which I just hard wired to a switch. But then when I would ride for maybe 20-30 min, I could feel, what I thought was the engine getting really hot, and the quad would start to backfire and have complete loss of power. (Mash the throttle and it will take off really slow and not want to climb hills and such)
After more research and pulling my hair out, I read about possible exhaust leaks, which it turns out it was leaking on the rear exhaust.(only had one nut.....) I then got the exhaust tight and stopped the leak. The quad seemed to get a lot more power and of course quit burning my leg from the leaking exhaust and I was happy... for about 20-30min until the quad warmed up and it lost it's power and starting to backfire again... I pulled the plugs and noticed they were fouled up and rather black.(cleaned them up and put them back in, they seem to be in good condition, were just dirty with black soot) I read about the choke maybe being stuck and/or running too rich. I pulled off the air filter, looked down in the carb and fired up the quad. The back carb was locked up (when hitting the throttle or using the choke the thing would stay closed. I pulled the plastic cap off the rear carb, cleaned the spring and made sure the rubber gasket thing was not cracked or broken. I put it back together and fired it up, and the back carb is now working in sink with the front carb when throttling.
I again was happy thinking I have fixed the problem..... but again, my happiness only lasted for 20-30min (until it got nice and warm) and then I lost it's power and it started to backfire and sputter again. I stopped the quad and pulled the air filter off to make sure both carbs were still working and they both are.
I have read about maybe needing to adjust the pilot screws on the bottom of the carb and making sure they are both at 2-2.5 turns. I have also read about it maybe being a full pump / vacuum problem.... Before I go any further and stress myself out anymore I thought I would ask around to see if anyone knew what my problem is and what the fix is. Any help would be great!
tldr: Quad runs great when first started. After 10-30min of riding the quad will lose power (Mash the throttle and it will take off really slow and not want to climb hills and such) and start to backfire and sputter.
Side note: While I was cleaning the spring on the back carb, I noticed two "nipples" on the bottom of the carb with nothing attached to them. I also found a long hose that splits at the end into two small hoses just laying under the carb. (Long Y hose) I assume that goes on those nipples? I plugged them on and they fit snug, I then ran the end up the handle bars and poked out the front. I assume is was a vacuum or exhaust for the carbs? After doing so, I did not notice any change in how the quad was running, besides the same problems with loss of power and backfiring / sputtering after being driven for a bit.
