looking for any input with a problem I'm having on my 748bp, at low revs I sometimes get a cough that sounds like it comes from the airbox and the bike looses power for just a second, runs fine at all other throttle positions ?
An air leak on the intake side will make it do that. Could also be the TPS being out or the throttle bodies not being synchronized correctly. Basically running lean will make it do that.
Or old crank sensor giving a marginal pulse at low revs. Heat weakens the magnet over time. Replaced it on my 2000 996, which had similar symptoms. Hasn't missed a beat since.
Think I have a solution, changed the complete ECU, the bike now runs noticeably cooler and the stutter has gone, I am assuming the original ECU is trimmed to lean or the Eprom is wrong.
Realise that OP is now sorted but for benefit of historical searches:- I had the identical problem - a cough in a specific part of the rev range; consistent severity and always at the same revs. Attempt #1 - trim it at the ECU ...... improved a little and for a short time. Then problem returned. Attempt #2 - create custom EPROM on rolling road. Fuels perfectly and has never coughed again in over 13 years.
