Dellorto jetting for high altitude

GoldenMotor.com

Royale

New Member
Oct 13, 2009
23
0
0
Colorado
I just about have all the parts for my motor build. I was going to order a better filter for my Dellorto from treatland and got thinking about jetting. I live in the Denver area which is over 5,000ft.

I already know I'm going to have to lean it out a good amount over stock, but while I'm ordering things I was curious if anyone had any knowledge of what range of Dellorto jets I should order? There isn't a whole lot of info about picking sizes for different altitudes for those jets and at $20+ per pack the trial and error method isn't an option.

I've already waited two weeks and still haven't received my new cylinder jug, which I guess are impossible to come by these days. So the last thing I want to do once I get that and get it all together, is have to order jets to get it to run right... and wait even longer.
 

F_Rod81

Dealer
Jan 1, 2011
1,031
2
0
Denver, CO
I just about have all the parts for my motor build. I was going to order a better filter for my Dellorto from treatland and got thinking about jetting. I live in the Denver area which is over 5,000ft.

I already know I'm going to have to lean it out a good amount over stock, but while I'm ordering things I was curious if anyone had any knowledge of what range of Dellorto jets I should order? There isn't a whole lot of info about picking sizes for different altitudes for those jets and at $20+ per pack the trial and error method isn't an option.

I've already waited two weeks and still haven't received my new cylinder jug, which I guess are impossible to come by these days. So the last thing I want to do once I get that and get it all together, is have to order jets to get it to run right... and wait even longer.
Hi there,

There is no one specific jet that will work... all engines are different. I live in the Denver area as well and have a few different motors. My 2 strokes all have the same performance parts on them and they all act totally different. I have a F80 from Dax that likes to run a "62 jet" (8 sizes smaller then stock). I have a GT5 that likes to run rich and has a "72 jet" (2 sizes bigger then stock). My 99cc 4 stroke out of the box runs perfectly with a "70 jet" in it. It all depends on your setup. Every little thing that you do to these motors will affect the jetting positively or negatively. I say get your project complete and see how your motor is acting once it's in riding condition. The science would point to needing a smaller jet for this altitude; but that's not always the case.
 

Royale

New Member
Oct 13, 2009
23
0
0
Colorado
Thank you!

That's exactly the type of information I was looking for. Hopefully my jug gets here soon so I can put this thing together!