Carb Slide Lift Hole Drilling

[Gearhead]

Guys,

 

Dynojet kits generally consist of a needle, main jet, and spring for each carb, as well as a drill bit to enlarge the slide lift holes. What is the effect of enlarging those holes? What if I put in the parts but don't drill the slides?

 

It seems to me that enlarging the holes will increase the RATE of slide lift, but not the overall lift. Will that have more effect on airflow or fuel flow? Could NOT drilling it cause a lean stumble on quick throttle opening?

 

Your opinions please!

 

Thanks,

Jeremy

[Squeeze]

Hi Jeremy,

 

not to drill the Lifter Holes is a bad Idea.

 

You have to see these Kits as a whole new System. If you put on other Springs, you have to adjust the Force to the Sliders matching the Load of the new Springs.

 

Friend of mine mounted a Stage1 Kit on his Max, didn't drill out the Holes and expierenced a really bad Gas Mileage and a bad Throttle Response. He found some Horses during his Tests but, tinkered a Lot on Idle mixture Screw and so on, but couldn't resolve the Issue. He dismounted later these Days. He really didn't want to drill the Holes and so, it did not happen to work right.

 

Also, i really recommend to set the Floater Heights exactly, while working on the Carbs.

[pegscraper]

Am I right, Squeeze, that drilling out the slide holes causes them to open earlier in the operation of opening the throttle, needing less manifold vacuum drop to cause them to open?

 

Are the Dynojet springs stronger or weaker than stock?

[Squeeze]

Am I right, Squeeze, that drilling out the slide holes causes them to open earlier in the operation of opening the throttle, needing less manifold vacuum drop to cause them to open?

...

 

 

Yes, that's right.

 

The Dyno Springs are weaker than Stock Springs

 

Because of their different Needles, they have a complete other Setup. during the Operation Range of Needle/Jet Needle Functions.

 

If you do not drill the Holes, it just doesn't work as it should.