Engine Power Loss

Energy One

ScubaJustin

Member
Hello all! I am looking for some help and suggestions as always! I have an 09 Mastiff with dual runner intake, big radius pipes, .585 cam and about 3200 miles on her. The cam is the most recent upgrade, roughly 500 miles ago? I did an oil change the weekend prior and took the bike out for a spin and it still ran like her normal raped ape self!! Then the following weekend I took the bike for a spin and roughly 3 minutes from the house the motor lost 95% of her power, no abnormal lights on the speedo, no abnormal lights on the ehc...not that I have them memorized, the motor still increased RPM's but could barely move the bike, exhaust note changed and we slowly limped home. I looked over everything and jumped out as abnormal to me, I recranked it and it sounded normal, roughly 2-3 minutes of running and the exhaust note changed again...I wasn't riding but I am sure the power would have dumped again. Before I tear into anything I just wanted to poll the community and see if anyone has some suggestions on where to start? I am leaning towards an ignition issue, something is telling it to go to a reduced power mode like engine overheat or something? As always, thanks for being a great community willing to help!!!
 

ksmike

Active Member
Is this an EFI engine? If so , you could try unhooking the battery for a few minutes to see if letting the computer(ECU) reset does anything to change the problem.
 

ScubaJustin

Member
Also, when I shut it down and restart everything runs normal, normal sound/power for a couple minutes then limp mode? Should I still check compression? I only ask because I do not currently have a gauge, thanks guys!
 
Also, when I shut it down and restart everything runs normal, normal sound/power for a couple minutes then limp mode? Should I still check compression? I only ask because I do not currently have a gauge, thanks guys!
You can rev the motor to several thousand rpm and evrything sounds okay? Then after a few minutes it starts running like crap?
 
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