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748 Eprom Confusion

Discussion in '748 / 916 / 996 / 998' started by 748rdave, Jul 18, 2020.

  1. looked up my spare eprom for a face book user last night, only to notice the my spare should in theory be the one fitted to the bike if the 50mm termi’s are fitted which they are. I’ve done about 70 miles since ownership and to be honest it goes as good as my old 748r did with a FIM eprom. No signs of running lean if anything very slightly rich. Then again as the bike is relatively new to me I have not pushed it past 8/9k rpm. The bike went through a major engine rebuild in Feb 2016 and since then serviced every 12 months. Surely someone would have noticed if the bike was not running correctly. Can’t see me ever pushing the bike anywhere near to its max engine rpm, due my age and always riding within my own capabilities. Not sure if the standard eproms can be reprogrammed. Could it be possible that the eprom fitted gave better results than the one supplied with the race cans ??

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  2. Dave, if the standard eprom (076) fitted has been reflashed after a dyno set up for the bike, in whatever configuration is in, it should work much better than the one supplied with race termis. Preprogrammed eproms sold for and with replacement cans (and the FIM ones) are approximate at best and will never get the same precise set up and accurate running than one that has been properly mapped and reflashed for the specific bike. Also the eprom set up for the race pipes may be less to your taste for road use if the power is tuned right to the red line for the race pipes. The differences between the standard, aftermarket 'performance' and a properly mapped eprom could be as much as 10bhp on your bike
     
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  3. Dave,

    I think? your spare EPROM is for Twin seat Racing Silencers so Bip with termis and not shower injectors as the R. I have no idea how different the chips are for fuelling, spark advance etc.

    My experience of setting up quite a few 4 valve bikes is that IF! the TPS base setting (used as look up for EPROM address) is as per the factory figures, throttle sync is correct as well as balance and CO then the bikes run as designed which I have always found to be quite satisfactory!

    I have however seen a Dyno 'expert' attempting to set up fuelling with probes in both silencers!:astonished:
     
    #3 Rman, Jul 18, 2020
    Last edited: Jul 18, 2020
  4. Denzil thanks for the information that explains why the bike runs so well.
     
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