Carb balancing

[streetf2]

Are these carb balancing thingys you can buy for about £40 any good and are they easy to attach or set up and use.

[crookster]

never used the one you are talking about mate i bought one off e-bay i think it was about 12 quid brilliant idea just 2 simple pipes with ball bearings in i was amazed but it was so simple to use and it worked.

[sirch345]

I also bought one of those carb balancers that crookster is referring too and thought it very good value for the money here's a link for it:-

http://cgi.ebay.co.uk/NEW-Motorcycle-Ca ... dZViewItem

[richard]

balancers are easy to use and can smooth out the vibes on your firestorm,
hardest part is getting the vaccum hoses onto the take offs, the front may not be fitted with a jet - just a bolt instead, the rear is the vacc. pipe for the fuel tank - you may need to splice it keep the bike running and take a reading at the same time ( if you have a scott oiler its usually T'ed into this rear pipe and you simply disconnect the scottoiler )

the adjustment process is pretty easy

Overall, well worth doing - the bike feels so 'sharp' afterwards. I've left a small amount of hose on the front jet and capped it with a golf-tee (!!) just for easy access.

cheers
richard

[Pete.L]

I've left a small amount of hose on the front jet and capped it with a golf-tee (!!) just for easy access.

I like the way you think Rich
I would also like to add it's probably worth while checking the calibration of you gages before you start. I couldn't set the carbs up very well with a new set I had bought my self and it turned out to be the calibration.
It's dead easy to do on the dial type. Just buy some T pieces from your local car accessory shop, link all the gages together and have a single pipe going off to the bike (so it's sucking on all of the gages). They should all read the same. if they don't just tweak the adjustment screw until they do.
Then you're ready to balance away until your hearts content
Pete.l

[streetf2]

Thanks sounds easy enough to attach but not sure what will be adjusting if i find they are out and if i leave pipes attached with blanks in end so that i can attach guages easily can i make any adjustments withoout removing tank while engine is running.

[LotusSevenMan]

With the type of balancer Sirch is suggesting it is self calibrating. One ball is using gravity as the centre position identifier and then the second ball is in 'conflict' with the other two cylinders. If it is pulled harder by one cylinder than the other then the ball will not be as it should be ie one ball below the other............ (oy, no rudeness)
If all is in equlibrium with both sucking the same amount then all is well.

Why did Vicky Butler-Henderson and Billie Piper just come to mind !!!!

[Badger]

I've got one for sale if anyone's interested, only used it once, worked ok, but then I sold the bike.

Alan

[streetf2]

ye iam only live in dudley what type is it and how much would you like for it

[Badger]

Streetf2 send you a PM

Alan

[LotusSevenMan]

So, StreetF2. Did ya buy Alans ?

I made a set after a well know figure on here talked me through his set.
Did the job yesterday. The carbs were enough out to say it was well worth doing the job!!! The tickover became noticeably smoother as did the static pick-up but it started pouring down with rain so yet to road test it.

Mine is very similar to:-

http://cgi.ebay.co.uk/NEW-Motorcycle-Ca ... dZViewItem

[Geordie]

Just about to fit balancer tubes to my carbs and had a mad stupid brainwave .. heres an idea .. why bother with balancing the carbs at all .. just connect the two vaccum take-offs to each other, then the pressure would equalise between the two inlet tracts and surely avoid any imbalance issues .. ??????!!!!!!

Cmon what dy all think ...

G

[tony.mon]

Nice try, but the imbalance is between the two carbs, strictly it's between the amount of lift each carbs gives to its slide for a given amount of vacuum.
There might be minor differences in spring length and tension, the slides might fit slightly better in one carb, one cylinder might have a bit more compression or ring leakage, etc, etc.

So what you're adjusting is trying to achieve an equal slide lift in each carb for the amount of vacuum there actually is in each inlet tract, i.e. that the carbs open the same amount at the same time.

Slightly more technically, because the pilot emulsion tubes' efficiency varies according to the flow of air past them (due to the Venturi effect) you're trying to get the same fuelling and therefore cylinder performance in each cylinder- working together as opposed to one "pulling" the other along by working harder than its mate.

Once you're on main jets the effect is not so noticeable, that's why you balance the carbs at around 2,000-2,500; this is where the flow past the pilots has the most noticeable effect.

My brain hurts now, so I have to go and sit down with a warm Performance Bikes mag for a bit.........

[Geordie]

Ha !

Yes I thought there would be more science behind the reason for doing it or why would there even be bleed holes to use. I follow what you are saying .. air flow, temperature, air pressure, slight imbalances in carb setup can basically be evened out by comparing the vaccum levels at part throttle. It is amazing really how accurate and economical dare i say it that carburettors are given all the variables and delicate moving parts and pressures .. !
Most light aircraft still use carbs with maunal mixture control adjusted by manually monitoring an inlet manifold vaccum gauge, engine revs and exhaust gas temperature gauges .. then also having to remember the freezing levels and operate a carb heat flap every so often to direct hot air from around the exhaust into the air intake so that it melts any ice that has formed over the venturi due to the pressure drop as air flow increases through the venturi ... a head wombles .. forget that and your engines oot and your in the drink .. ! I digress

Cheers
G