running rough at low revs

[CMSMJ1]

you would do well to pick up a Haynes manual from the shops..

Taking the carbs on and off is a rite of passage on these bikes! It can seem daunting...but you get used to it and to take them off, clean and service them and refit is a matter of pride and you'll then know you have saved over a hundred quid and performed some valuable work on the bike.

Carbs have multiple jets in them. DO a search and you'll find some thread where the carbs are explained better.

Bikes are simple things that were put together by normal blokes - nothing magical or scary about them.

[j77drs]

your right, i already have the airbox etc off and almost readin to take carbs off, i just dont want to disturb anything and mess about with mixture etc, it does show you in the haynes manual where the pilot jet is but think the carbs have to come off to access it,

i do have a haynes manual ready,

i just can see where the carbs are bolted / screwed on,

i think its best if i can get them off and clean them along with a new regulator,

regarding the regulator, is there an upgrade ?

[Cammo]

regarding the regulator, is there an upgrade ?

I use Yamaha R6 units, very cheap 2nd hand and a lot more reliable than any honda unit. The later the model the better.

Quite easy to mount and wire up.

[Biff]

Things wear on these bikes due to age, it could be something as remote as a leaking carb diaphram. Unfortunately you won't know until you inspect all possible causes.

I had the same problem with the nc race bike last few weeks, found a split in the rubber diaphram on pot 2 in the carbs, after spending ££££££s on renewing parts that made no differance!!

The bike felt as if it was only running on 3 cylinders which in effect it was, and it would struggle around 6000rpm,
Just check the rubbers as mine had a chunk missing where there is a little D shape that goes round a small air jet on the diaphram, also check condition of the gaskets etc....

[j77drs]

i have a haynes manual but its not clear how to take the carbs off

[Biff]

If you look between the bottom of the carbs and the top of the frame you will see the clamps holding the carbs inplace,
you will need a philips to undo the top clamps( just loosen off a few turns), do this to all 4, you may need a torch to see them better, then just pull the carbs up, i find it easier to take the throttle cables off with the carbs lifted off..

Simples...

[Cammo]

If you look between the bottom of the carbs and the top of the frame you will see the clamps holding the carbs inplace,
you will need a philips to undo the top clamps( just loosen off a few turns), do this to all 4, you may need a torch to see them better, then just pull the carbs up, i find it easier to take the throttle cables off with the carbs lifted off..

^ Yup. Make sure to remove the cable choke from the carbs and the idle adjustor from the frame bracket before trying to lift the carbs off.

The carbs usually need a fair old pull to get them off. If they've been on there for a decade or more you might even need to lever them off with a bit of wood or similar.