First question ?
Do the carb diaphrams have a small pressed hole near the outer edge as standard.
All 4 of mine have what looks like a semi-pressed ring (approx 3mm) and i can see daylight through all 4 of them where it's split, some holes are slightly bigger than others.
Am i wrong to think they all should be airtight ???

The bike runs fine on throttle, but when taking it steady the bike starts to really hold back (maybe 4k rpm) and if i pull the clutch in it will instantly die if i open the throttle at this point it's fine and will then idle ok, this takes for some interesting riding at the moment
I'm thinking it's something on the fuel side although i can't find anything wrong, but of course i could be wrong.

Second question ?
Is there any way to roughly balance the carbs without vaccum gauges ?

regards as always

Smxr wrote:First question ?
Do the carb diaphrams have a small pressed hole near the outer edge as standard.
All 4 of mine have what looks like a semi-pressed ring (approx 3mm) and i can see daylight through all 4 of them where it's split, some holes are slightly bigger than others.
Am i wrong to think they all should be airtight ???

In the absence of more knowledgable answers: here is a picture, not of the diaphragm unfortunately, but it's seat:



This is my 3EN2. The bit in the red circle is made airtight by an o ring, seperate to the daphragm. The diaphragm seats in the big circle. There shouldn't be holes, but perhaps other models have the diaphragm attached to a little o-ring? Doesn't sound likely to me though.

Smxr wrote:The bike runs fine on throttle, but when taking it steady the bike starts to really hold back (maybe 4k rpm) and if i pull the clutch in it will instantly die if i open the throttle at this point it's fine and will then idle ok, this takes for some interesting riding at the moment

This is exactly what my RF600 did when I didn't tighten up the carb rubbers properly, so air was getting in where it shouldn't. So it sounds like the diaphragms are the cause. Picture?

Second question ?
Is there any way to roughly balance the carbs without vaccum gauges ?

You could make some from fishtank tubing:

http://www.powerchutes.com/manometer.asp

It's easy enough, I did it but then bought a pro one. The one I made is more accurate.

all the ones i've seen have no holes! they won't work properly if they aren't a good seal! sound to mee like someone has been a git heavy handed fitting them and inched them somehow? try some rubber glue like the stuf you use on innertubes as a temp fix!

Cheer's for the reply's.

The little 'O' rings are fine and all in place, the small holes were on the actual diaphram.

As suggested (thanks) i've already removed the carbs again and patched up all the holes with tiny pieces of Vinyl glove and bicycle rubber solution, this seemed to seal them fine for a temporary measure at least.

The result was it made no change to the bikes running whatsoever, so still has the flat spot

I'm thinking it might well be the balancing or as suggested an air leak.
I've checked the rubbers and can't visibly see any problems with the carb seating

Unfortunately the bike is up for sale now due to a new bike purchase so may well be left to new owner to fine tune it, i'm sure someone with more knowledge will improve it no problem.

Thanks guys.

Id replace the carbs with another bank off e-bay first then see how it runs ... it sounds like the idle jets, but then again you,d better check the exup too