Sputtering/Hesitation when going more than 65% throttle

[IIIHorseman]

When I'm riding the bike on the road, whenever I throttle up to 65% and up, I get a hesitation feedback followed by sputtering that doesn't seem to go away. Any idea what may be going on? I'm running on a Lyen controller on a BMC motor

so here is the stats of the bike:

9 FET 3077 Mark II sensored LYEN edition controller
Software build (unknown-I do have the program cable that comes with it though)
cycle analyst (speed sensor not yet configured)
throttle (crystalite twist throttle)

Motor: BMC Cruiser V4 8T
Battery: 48V10AH Battery pack with 25Amp continuous current with a max of 35 (although cycle analyst says it runs at 54V)

Any ideas?
Thanks

 

[IIIHorseman]

Forgot to mention I have the cycle analyst running at 35amps cut-off

 

[John in CR]

First disconnect the CA to make sure it isn't causing an issue due to incomplete setup. Is the CA calibrated? If so, does the wheel spin up to WOT with no load, and what is the no-load current?

Does the motor pull strongly during acceleration, or does it limit to less than WOT even during acceleration?

I've heard of BMC's being finicky about controllers but not in a while.

 

[biohazardman]

I have never had either of my BMCs running perfect in the 7K+ miles I have been riding them @ 48-66V. The stock BMC controller I received with my V2S kit was weak on acceleration and I would pedal to help to 16-18MPH and then it was fine. I just ran it that way for a year or so till I thought I would see what it would do on a hill and so did not pedal up the steep grade. It pulled the hill ok but was never the same and died a few months later. I replaced it with a Lyen 12 FET Version1. It needed me to pedal as well if I wanted to accelerate decent. After 16-18 MPH or so it pulled hard all the way to near 40 MPH. I never did try programming the V1. It was near 5K miles later I spoke with Lyen about this and he said I had purchased the wrong controller and offered a trade. I just kept it and ordered a version 2. Changed to a V2T motor then thinking it would be a bit more efficient and have better acceleration as well. The V2T stutters when I try to cruise at 12-18MPH but accelerates quickly from a stop and continues to do so smoothly if not babied to any speed. It climbs hills very well also. I have tried at least 25 different settings and while some are better than others none give me both the acceleration and cruising without stuttering at 12-18MPH. I seem to be able to have one or the other. Still the bike is fine as is I usually ride 20-25 mph so don't worry about it much. Can't help you with the exact settings on the programming but if you mess with it a bit you will find something acceptable.

 

[dogman dan]

One thing that can cause that problem, is a partialy severed phase wire. One wire, with just a few strands left, but still connected will run smooth at low power, but under full throttle and a load, it will only push the watts it can, and the motor will start to chatter.

Could be many other things, but checking for a nicked wire is at least easy to eliminate.