Carb balancing

[chi kung]

Is there a guide on here on how to balance carbs? Thanks.

[benny hedges]

what do you want to know????
have you got the vacuum take-off points ready???
go for a ride & get the engine to normal temp, nice & hot.
set tickover to about 2500, attach the gauges and turn the adjustment screw (1/2way along, just under the edge of the tank, on the LEFT (ed lol wtf!)
you only have to balance the rear to the front, theres only one screw.

normal vacuum (according to the manual) is around 20mm/hg, unless you have a dynojet kit fitted and drilled slides, in which case it will probably be half that.

between each adjustment, give the bike a good revving and let it settle down, as you are adjusting the way the throttle cables act on the linkage.
you will probably find it isnt far out.
if it's miles out, before you adjust anything, check the vacuum lines aren't perished or burnt by the rear exhaust downpipe, and that there is no air leak at the carb intake rubbers.

[futterbingers]

Is there a cheaper way of balancing carbs, rather than buying carbtunes?
Is it really obvious when they need a 'do'?

[tony.mon]

Is there a cheaper way of balancing carbs, rather than buying carbtunes?
Is it really obvious when they need a 'do'?

Yep. Find a mate with a carbtune.



Or come to the summer meetup, we'll have a few at hand.

[sirch345]

Is there a cheaper way of balancing carbs, rather than buying carbtunes?
Is it really obvious when they need a 'do'?

chi kung,
I find one of these carb balancers does the job just fine:-
http://cgi.ebay.co.uk/UNIVERSAL-MOTORCY ... 4cf02ad0e1

You don't really notice them going out of balance (unless of course they are really out) as it happens gradually and you adjust to it as it happens, but if they are out a fair amount you do notice it after you've balanced them,

Chris.

[chi kung]

Thanks for the replies guys. I have borrowed a carbtune but dont know where to plug it all in. If someone could give me some real basic instructions it would be great. I have not prepped the bike with take of points or anything.

Even better if someone is local they could show me and do theirs while they are here, or i can come to you?

thanks

[benny hedges]

squat down on the right hand side of the bike, just above the rad, look at the inlet rubber where the carb joins the front cylinder...
see that 8mm cap??
its a tw@ to get at but thats the vacuum take-off point for the front cylinder.
if you look in the workshop thread there's a link to where you can get some m5 adapters to screw in there, with a length of tube to attach to the gauge.
be sure to put some thread sealant on the threads of the adapter so it doesnt work loose or leak vacuum.
once you've struggled to fit the adapter you wont have to do it again, just blank off the tube and tuck it out of the way (where it won't get burnt)

the rear cylinder, you will need a tee connector and another length of pipe to break into the fuel tap vacuum pipe. (under the tank, the small hose that goes to the fuel tap - not the same diameter breather pipe attached to the tank)
again, once youve broke into it and attached the balancing pipe you won't have to do the job again.

someone recommended golf tees for blanking the hose off - i got some small valves cos ir pro
the rear vacuum take-off for the tank comes from under the rear cylinder carb inlet rubber, just visible from the left side of the bike, on the front of the rear cylinder.

there is no easy way to get at the blanking cap, unless you are prepared to remove the tank, airbox, carbs & heatshield.
if you do that, be sure to stuff some bog roll in the inlet ports as soon as they are visible - or you WILL drop something inside!

the rest is easy.
make sure the bike is good and hot tho or you will crouton it up by meddling.
set a high idle - 2500 - 3000rpm, adjust the balance screw and give the bike a revving between adjustments.

if you are not sure what im on about, copy the shop manual from the link in the workshop section

[tony.mon]

I'd just add that the M5 adaptors usually come with O-rings fitted, take these off if you're fitting them permanently, and as Benny says, use loctite instead.

[marlbororman]

I'd just add that the M5 adaptors usually come with O-rings fitted, take these off if you're fitting them permanently, and as Benny says, use loctite instead.

Hmmm didnt know about removing the o ring, i`ll remember to do that when i fit mine in a day or so...cheers

[futterbingers]

When/ where is the summer meet up? It could be a bit far for me but you never know. I'm moving back to uk at end of sept anyway.

[marlbororman]

Its weekend of july 24th, and in Liecester mate.

[Stratman]

I've bought one of the ball bearing type balancers that Chris recommends. Presumably I could leave one of the adaptors supplied with this kit in the front take off and attach a tube to it with a suitable "bung", golf tee or whatever?

[marlbororman]

Yep, thats what i did yesterday, just need to get the bike back home now, then will balance the carbs, probs thursday