Gilera DNA 50 Stock Engine with Yasuni Z & Main Jet Size

Hi all,

I have a stock Gilera DNA 50 2006 and about to fit my newly arrived Yasuni Z pipe. I have just finished reading the excellent guide on Scooter Shack regarding jetting. It states that up to an 8% (sometimes more) upjet is required for exhaust upgrade. Now my calculation is that from a standard 56 + 8% = approx. 60, but some sites state start with a 75 mainjet. This seems like a large enough discrepancy to warrant this forum post.

Has anyone got the same setup and could possible advise? Any knowledgeable help would be mcuh appreciated.

Cheers,
Tris

 

Finally got some spare time to pull something apart. Managed to fit the Yasuni Z pipe, remove the brass plate from carb, fit 5g rollers and new 65 main jet.

After a lengthly plug testing session out on the open road armed with two screwdrivers, a plug spanner and a box of main jets I seem have ended up with a 78 main jet.

What I did was ride the bike along a long straight stretch at full throttle, then chop the engine from (turned the key off) whilst pulling over to an immediate stop to pull out the plug. I noticed the plug was burning near white seeming way too lean using the 65 main jet.

I had not much experience with jetting, but after I went up to around 72 main jet the power increase was very noticable along with a healthier engine note. There seemed to be a slight increase in performance with a 78 and slightly less with an 80. So I figured 78 main jet was the one. Is this possible with standard airbox?

 

Sounds perfect, you've done a good job considering you hadn't done it before Its great to find someone that actually took the advice on here and bought a box of jets and had a good outcome.

Might be worth doing a chop with the current jet and put a picture of the plug on here, just to be sure

 

Will do when the weather is better. I took a photo of the original plug (before new plug with upgrades) in good lighting but it looked completely different in photo to real life.