Hey just wondering how you balance carbs on these lil v4's anyone know how?

yeah i would like to know this to , obviously use a carb tune ie a morgan one , but i keep hearing this 1mm drill bit method , i have no idea on whats involved could some one shed some light on this as id like to sort me carbs out as im in the middle doing shims and iv been told after doin this the carbs will need rebalancing

i see a how to guide coming up.

Carb balancings easy.

Get a carb balancer first (set of vaccumn gauges)

If you look in the V of the cylinder heads you'll see a (+) head screw that can be removed to allow you to fit a vaccumn pipe take off, these come with most carb balancers, if not Morgan sell them.

You fit a vaccumn pipe to each cylinder.. the NC24 has a screw for the cylinder with the vaccumn pipe for the fuel tank, i'm not sure if the NC30 has one, if not you could just use the vaccumn take off point for the tank.

Underneath the carbs there are 3 x (-) Head screws, you can also fit a 7mm socket on these.

Turning these screws affects the opening of the butterfly and how much air is drawn through the carb.

Set your bike to a fast idle, roughly 1600rpm and allow it to warm slightly.

Now looking at your gauges, work around the carbs turning the screws. Turning a screw in or out will cause the vaccumn of that carb to rise or fall. You want to see what screw affects what carb and balance the 3 carbs that can be adjusted to match the one that can't (this carb is known as the base carb)

The drill bit method involves matching the openings of the butterflys on the bench.. this will result in carbs that are fairly close to vaccumn balancing, sometimes identical but since your matching the openings rather than specific vaccumn your not taking into account air fluctuations in the airbox system.

Getting to the adjuster screws can be quite fiddley as there in the middle of a narrow and HOT V... morgan sell a 45 degree angled screwdriver which is highly recommended for this job.

The bench method obviously requires you remove the carbs.

Spike16 wrote:Hey just wondering how you balance carbs on these lil v4's anyone know how?

You are kidding?

You got the skills laddo

in a nutshell - use a couple of small bits and balance the opening of the butterflies using the procedure you would use in the Haynes. Stick the first one in then make sure the next butterfly is opening exactly the same....keep on going..and you are done.

Simple.

CMSMJ1 wrote: a nutshell - use a couple of small bits and balance the opening of the butterflies using the procedure you would use in the Haynes. Stick the first one in then make sure the next butterfly is opening exactly the same....keep on going..and you are done.

Simple.

Yep, all you're doing is setting the carb butterflies to be open the same amount by using a spacer (drill bit etc). Adjust them all in the usual order (haynes) so that the spacer just fits.

Best thing is you can do this with carbs off the bike when you're cleaning/jetting them etc. It may not be as accurate as balancing on the bike with vacuum gauges, but it still works a treat!

Get the proper tools from morgan. Not very expensive. Great tools.

If it's a track or racebike forget using carb balance gauges.

Balancing will only provide an even idle and nothing more.

carbs are off at the mo so I will set them up using the drill bit method, i cant be arsed with vec balancing them as they are for my racer and as data says if its not gona effect anything other than getting a balanced idle then as long as their close

Cheers guys

if your having it dyno'd with having the ram air fit, would it not just be worth taking it to the guy who's doing it and let him do it, i presume it will need bigger jets in?? save you trying to set it up then for them to put different jets in and set it up?