Quote:
Originally Posted by inkslngr7
Looking to talk to someone with SU experience. Wanting to run one on a retro Shovel project I'm building. I've picked up a few of them, one for sure I know was on a bike. Need to find an SU rebuilder! Can anyone help?
|
Hi just joined but I have rebuilt a few su's and tuned them for custom applications.
what hp are you expecting and what size su do have.
You will need the correct spring above the su piston and then select a needle close to you application then run it, use a colortune set the idle mixture then rev it up slowly noting the colour of the combustion flame you may be lucky and its all good
If not make a small ruler to sit in the dash pot as the piston rises using the colortune you will know how high the needle is out of the jet and the know where the needlle needs be thicker(leaner) or thinner(richer), winding the jet up and down while testing will help work out how thick or thin it should be referencing the size of the needle where the jet ends up and noting piston height again because it moves with air flow.
Sounds complicated but once set up it's straight forward. then check the su needle chart to see what needle you need.
Hope this helps I have needle charts here somewhere Tell me what su you have and your expected power and rpm range and I will see what I have for spring and needle starting point.