Butterfly adjustment?

[fox889]

Just bought one of these carb sync gadgets for my CR series throttle bodies, superb piece of kit for very little money.

I've adjusted all 3 bodies to read 1.2 on the scale, rear body has both chambers at 1.2 as do the middle pair of chambers, the front body has the right hand chamber at 1.2 but the left hand chamber is at 1.8 (still with me?) so, I've still got a bit of hesitation when 'feathering' the throttle at low revs i.e. going around town in 2nd, very embarassing!

My question is, can I adjust one of the butterflies a little to get the balance right do you think?

 

If anyone wants to look at the carb gadget there's a link below. I can only speak as I find, it worked well when I balanced them over the weekend.

 

Nick.

 

http://www.ebay.co.uk/itm/Dellorto-Weber-synchrometer-carb-balancer-tool-made-Germany-not-China-/290682796527?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43ae0b79ef

[Rien]

Hi, how did you no it is a butterfy that give the different value, yes it is possible but on what rpm do you have measure this, try on different rpm's say 1000, 1500 & 2000. Balancing ad iddle are not accurate in my opinion or you must temporary blank off the balancing pipes.

Take a cylinder leak and pressure test and see what this give before you try to adjust the butterfy or torn the delicate spindles.

 

Cheers,

 

Rien

[peejay4A]

Nick,

I agree with Rien, you need more airflow to set the butterflies. Those balancing devices are more accurate and readings reproducible around and above mid way through the range. Having said that you could have a twisted throttle spindle on the front throttle body. I think there's some advice on the forum about what to do if that turns out to be the case.

[fox889]

Hi, how did you no it is a butterfy that give the different value, yes it is possible but on what rpm do you have measure this, try on different rpm's say 1000, 1500 & 2000. Balancing ad iddle are not accurate in my opinion or you must temporary blank off the balancing pipes.

Take a cylinder leak and pressure test and see what this give before you try to adjust the butterfy or torn the delicate spindles.

 

Cheers,

 

Rien

 

 

The only reason Rien that I point the finger at the butterflies is that 5 out of 6 butterflies all read 1.2 on the carb balancer & the odd one out reads 1.8.

I did set the butterflies up at 900 rpm on tickover & you may have a good point in me trying to balance them at slightly higher revs.........I'll try this when the weather improves..............December!!!

 

Thanks

 

Nick.

[fox889]

Nick,

I agree with Rien, you need more airflow to set the butterflies. Those balancing devices are more accurate and readings reproducible around and above mid way through the range. Having said that you could have a twisted throttle spindle on the front throttle body. I think there's some advice on the forum about what to do if that turns out to be the case.

 

 

I saw a piece that said unscrew the two butterfly screws half a turn then snap shut the throttle several times to see if that would settle it down.

I think you & Rien have a good point about the revs, I balanced these at tickover (900rpm) so may be prudent to up the revs a bit & try again.

 

Thanks

 

Nick.

[Rien]

I saw a piece that said unscrew the two butterfly screws half a turn then snap shut the throttle several times to see if that would settle it down.

I think you & Rien have a good point about the revs, I balanced these at tickover (900rpm) so may be prudent to up the revs a bit & try again.

 

Thanks

 

Nick.

 

Yes that is possible but I prefer this methode with the bodies of the head so you can place a lamp on the rear so you can see the result.

Cheers,

 

Rien