NEW DIAL-IN MAIN JET
Posted: Thu Dec 29, 2005 1:51 am
Below is pictured a Spree carb with a real dial-in main jet.
After several months of trial and error, the persistence paid off.
The main jet is drilled oversized then adaptions made to accept the new needle with a good range of adjustments.
The only problem now is after 4-5 adjustments the o-ring leaks slightly.
This is due to the needle threads cutting in after 4-5 adjustments.
A new o-ring cost about $.30 so I've been changing it out till I got the ideal 12-1 air fuel ratio, then it will seal once the setting is final.
After bench testing this week, it runs real sweeeet! It never ran like this ever before!
Using a ported intake and adjusting the timing, with a cone air filter, this Spree sounds like it doesn't want to quit. Better throttle response and no bogging at high rpm.
Waiting for better weather to road test. Hope this snow goes away soon.


You can click to enlarge image.
This is a pro-type for viewing only. But you should be able to see the concept.
After several months of trial and error, the persistence paid off.
The main jet is drilled oversized then adaptions made to accept the new needle with a good range of adjustments.
The only problem now is after 4-5 adjustments the o-ring leaks slightly.
This is due to the needle threads cutting in after 4-5 adjustments.
A new o-ring cost about $.30 so I've been changing it out till I got the ideal 12-1 air fuel ratio, then it will seal once the setting is final.
After bench testing this week, it runs real sweeeet! It never ran like this ever before!
Using a ported intake and adjusting the timing, with a cone air filter, this Spree sounds like it doesn't want to quit. Better throttle response and no bogging at high rpm.
Waiting for better weather to road test. Hope this snow goes away soon.


You can click to enlarge image.
This is a pro-type for viewing only. But you should be able to see the concept.