Hi Guys, I'm sory that my first post is a "help me" post but I've been plagued with a fault for some time now and am getting quite frustrated with it. The problem is that when i'm out on the bike it is very hesitant through the rev range, at points it stops accelerating for a second or two and then you get a kick of power for a second then gone again and so on. (very dangerous for passing)

The odd things are:
If the bikes stood it idles smooth and rev's up cleanly everytime.
The problem doesn't seem to be present below about 7000rpm
The rev counter at times has been reading about 2-3x too high
And the whole lot has been reallly intermitent

For a few weeks it was off and on, either good one day bad the next, one day it was both good and bad twice, generally if the rev counter was reading wrong the hesitancy was there, Then it was fine for about a month (i ride it daily) and since it went after that month the rev counter has been reading accuratly but the bike is just really stuttery through the rev's.

ok, its had new oil, air, plugs, reg/rec, CDI (thought the old one was causing the problem) fuel filter is fine, I've not touched the carb's (nor do i wish to)

The only other thing is the neutral switch is on its way out, which is in the area of the pulse generator i think. no idea if theres any significance?

Anyone any ideas before i replace both coils/leads and the pulse generator?
any suggestions would be much appreciated (apolagies for the essay)

The way you describe the hesitancy it sounds like fuel starvation? My bike does it when it is too low on fuel, and on reserve.

Is the vacuum hose/tap in good condition and is the fuel filter clear?

+1 on fuel starvation (no idea about tacho - coincidence ?) could be something as simple as a clogged up fuel filter.

I had a similar prob on my race bike took the fuel filter off and it was fine.Was restricting the flow to much..

Check the vaccum pipe isn't split / frayed, if it's the original black rubber one you might wanna replace it.

It runs from cylinder #3 to the petrol tank tap.

When mine had a split in it, 8000rpm+ the bike ran like it was out of fuel.

I had a similar prob on my race bike took the fuel filter off and it was fine.Was restricting the flow to much..
I had a similar prob on my race bike took the fuel filter off and it was fine.Was restricting the flow to much..

do you mean a inline fuel filter, or the fuel tap filter that you removed?

when you say the rev counter reads out 2-3k, is that above your engine speed or below, and are you matching the revs to your road speed, eg. ( 40mph in 6th gear = roughly 4200rpm)

sorry just seen

The rev counter at times has been reading about 2-3x too high

i might be wrong but could it be the clutch slipping?????

Check all your earth connections are clean and tight. Take them off, clean them up and re-tighten. The tacho behaving strangely points to electrical problems and bad earthing affects this bike quite badly.
Also, as previously stated, check the vacuum hose to the fuel tap. It gets brittle and splits giving similar symptoms.

Good hunting.

TonyB is right here, although I doubt its a grounding problem as that tends to stop the bike starting altogether. I recently had very similar symptoms from my Kawasaki GPZ500s, i.e. rev counter going strange, engine hesitant and stuttery, except mine died 10 mins later. Turned out to be the alternator was partially broken and the battery had finally died (its a really old bike), so the ignition wasn't getting enough energy to operate properly.

Your problem is clearly intermittent, which could be a number of things; I'd check all of the connections to your coils (2 black plastic things with 2 red nobs on top on the left side of the bike, one on the subframe near your leg and the other on a bracket sat behind the top rad) and the connector to your alternator (right hand side of the bike, the big white connector sat in the bracket just below the main frame spar about level with the middle of your fuel tank). Just unclip them and check for corrosion, clean them with a wire brush if you need to, and refit them tightly.
Alternatively it could be your battery or alternator is smegged somehow. Put a voltage meter across your battery terminals if you've got one. It should read a solid 12-12.5 volts. If its less by more than .5, then its suspect. Alot more and its the problem itself. However, you've been able to start the bike using the battery, and that wouldn't be the case if it was shagged. So start her up with the rear seat panels removed, and use the voltage meter on the battery again. This time you should get 13.2-15.5v, according to my Haynes manual. 13.5v is usual. If less, then its your alternator causing the problems.
If not, then you got yourself a thinker! Take it to the garage.