I have put my MC18R5 back together and am experiencing a problem which I hope someone can help with.

If I run thru the gears up to approx 11000RPM and button off..... then wind the throttle back on I lose power briefly ...feels like 4 stroking both pistons. The longer I leave the the throttle shut the longer it takes to clear. Opening the throttle fully helps clear it or waiting longer on part throttle eventually clears it as well. Seems OK charging thru the gears or cruising.

The rear of the bike is semi splattered in black fluid from the cans (not sure where this is coming from, perhaps the rebuild, gearbox or simply too much fresh mixture finding its way into the pipes) .

I don't seem to be losing any gearbox oil although the test drives so far have only covered 40-80km. Idle is perfect after a carb rebuild. Bike has just had the crank rebuilt with new bearings and seals and I have stripped it once already to check I haven't crimped or damaged a seal after the first rebuild although I put the same seals back in and used plenty of Threebond 1104. Perhaps I damaged the seals the first time.

Have checked the TPS and solenoids against another NSR handy and they seem OK with a meter.

Am I right in assuming that if the right hand crank seal is gone only one cylinder would be affected?

Carbs are set up completely standard and I have the airbox mod with JHA cans otherwise standard.

Any Thoughts?