# 08 Brute mid throttle cutting out ??? HELP !



## muddymud (Jul 21, 2011)

Hey everyone, I was refered here by a buddy to see if anyone can help me out. I have a 08 BF750 EFI that I'm working on. It has the Fundy standard bore kit which was installed over a year ago and had been working great up until now. HMF slip on. PC3. This problem has gradually gotten worse until the point you can't ride it anymore. When the bike is cold, you can crank it up and rev it to the rev limiter about 3 or 4 times and then the problem starts. After about the 4th rev, it will start cutting out about mid throttle kinda like a limiter has been activated. NO codes or lights. I have hooked to the PC3 and watched rpms. Seems to happen in 4300-5000 range. I have added fuel and subtracted fuel here in this range with no improvements. I checked fuel pressure 40psi. It will never make it over 5,000rpms. The more throttle you give it, the worse. However, you can let off the throttle and it will idle with no problems. Any ideas on what to check next ? If it would be easier to call me, 919-202-0552, I would greatly appreciate the help. Thanks, Scott.. I've been messing with it for about a week now.


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## muddymud (Jul 21, 2011)

my bad, another buddy of mine has already posted here. http://www.mudinmyblood.net/forum/showthread.php?t=13396

But we still need the help. Not fixed.


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## wyo58 (May 13, 2011)

40 psi is not enough, the service manual wants 43 psi at idle with a maximum of 43.5. I'd guess that the pump sock is clogged or the pump itself is bad.


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## NMKawierider (Apr 11, 2009)

Also the 08s had issues with their crank position sensor. Might check that.


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## muddymud (Jul 21, 2011)

Thanks for all the help. Here is where I'm at. All sensors have checked good. I can turn the key on and off a few times then start it and it will rev out a few times good. Once it starts acting bad again after a few revs, I can turn key off and cycle key a few times to prime fuel pump and restart bike and it will rev again a few times. I just ordered a fuel pump, so I hope that fixes it. Does that sound about right?


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## brute21 (Mar 12, 2010)

its fuel pump 90% sure


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## oft brute (Jul 22, 2011)

90% of problems come from the pump on efi brutes,99% on built motors


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