# Adjusters on the diaphragm, for pumper jet carbs
**URL:** https://forum.motoguzziclub.co.uk/t/adjusters-on-the-diaphragm-for-pumper-jet-carbs/1387
**Category:** Big Block Tonti and Loop Frame models
**Created:** [23 June 2014 19:48 UTC](https://forum.motoguzziclub.co.uk/t/adjusters-on-the-diaphragm-for-pumper-jet-carbs/1387 "2014-06-23T19:48:58Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Exmembers](https://forum.motoguzziclub.co.uk/u/Exmembers)
#### Post date: [23 June 2014 19:48 UTC](https://forum.motoguzziclub.co.uk/t/adjusters-on-the-diaphragm-for-pumper-jet-carbs/1387/1 "2014-06-23T19:48:58Z")
Does anybody know the best way to set the adjusters on the diaphragm on pumper carbs on PHF Dell’Orto’s?
I would assume that screwing them incrementally to different (accurate) positions and test riding would be the best way without a dyno, but according to Haynes, they are pre-set at the factory, so no help there.
I just wondered if there were any “guideline” starter settings?
ReggieV2014-06-23 19:49:56
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### Author:  [@Exmembers](https://forum.motoguzziclub.co.uk/u/Exmembers)
#### Post date: [24 June 2014 09:48 UTC](https://forum.motoguzziclub.co.uk/t/adjusters-on-the-diaphragm-for-pumper-jet-carbs/1387/2 "2014-06-24T09:48:32Z")
about 4cc per 20 squirts i believe, although Ducati owners seem to favour 5cc although the red paint on them probably indicates that they dont expect you to adjust them…
various suggestions on how you might measure it on this thread…
[how to set up dellorto accelerator pumps - seems like pissing in the wind | Page 2 | LaverdaForum](http://www.laverdaforum.com/forum/index.php?topic=85883.0NeilD2014-06-24) 09:59:27
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### Author:  [@Exmembers](https://forum.motoguzziclub.co.uk/u/Exmembers)
#### Post date: [24 June 2014 17:00 UTC](https://forum.motoguzziclub.co.uk/t/adjusters-on-the-diaphragm-for-pumper-jet-carbs/1387/3 "2014-06-24T17:00:08Z")
Thanks Neil, that was very useful, I shall use that method to check mine.
Thanks,
ReggieV