Hi Afriend of mine has a 91 RS, when he is on high revs, he says it gives him the feling of running out of fuel, any thoughts anybody. Somebody mention it might be his wiring loom, that leads me onto my question, are the 91 and 92 looms compatable, thanks

The looms must be the same. I will check the book by tomorrow.
Maybe a carb problem?

They are a different part no: in the book, as is the pgm, also the 92 has a digital temp gauge, whether Honda changed the part no of the pgm because it was a different year i dont know, but i would have thought the loom was a different no due to the fact the temp gauges are different ie, one digital, one capillary, so i would imagine that apart from the connection for the temp gauge they would be compatible.
_________________
Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto

Just a thought........The 91 RS has a 12V battery pack, which needs to be fully charged before running the bike. There is no alternator charging circuit from the engine rotor. When running under high load / high revs with a flat battery, you can sometimes expereince what feels like a misfire.

Also, is he using a quick-release fuel line connector? They come in different bore sizes, sometimes the smaller ones don't flow enough fuel at maximum engine speed and it can starve the carbs.
_________________
Rich
MC21 Track Bike / RS250 NF5 'Spencer', NX5 'Cadalora' & NXA 'Aoyama' / RS500 / Two Brothers Racing RC30

Following on from Rich G's post about the battery being fully charged, my 1990 RS also has a Battery Pack and I have ridden the bike with the battery disconnected , the first thing I noticed was the Rev Counter swings around and a slight drop in performance due to the Power Valve Motor not operating , but the engine did not suffer from any misfire.
I hope this information is of some help .

John

I found my 92 NF5 bike wouldn't run at all well without a fully charged battery. It only happened the once, but the rev counter needle flailed around wildly despite revs being constant. Then once it the pits, it wouldn't run at all. Changed over batterys, and worked fine for the rest of the day.

Well it looks as if the 1990 and the 1992 both react differently when ran with the battery disconnected , so maybe the 1991 has a similar system to the 1992 and reacts in the same way when either the battery is flat or disconnected .

John.