Hey everyone, I believe I am getting A slight surge at 57 to 6000rpm. If I back off a touch it's gone. It I give it more throttle it pulls smooth and hard. I read another members post about possibly the slide at full open due to the stronger engine signal and causing a over fueling at part throttle . That's makes sense. I think I may try the stock spring. What do you think? Is this plausible?

330 bore ,132 main ,38 pilot ,KDX snorkel ,factory filter, fmf p bomb , Q4 , DJ slide spring , DJ needle @ 3 clip.

Thanks

 

If you have not done the rectifier mod you should do that first as it fixes some surging phenomenon. Why not just post this in the other 2 big bore carb threads we have going?...just curious....

 

Sure it's related but not one derail someone's thread.

 

I'll chime in a bit - this stuff is really not for noobie tuners tho.. The stock spring will "slow" slide response and action compared to the DJ spring. When used appropriately, this can significantly increase throttle response and power levels below 7k rpm.

Conceptually, It spreads the fueling curve out. Helping to even out the AFR @ WOT as RPM's rise from low to mid to top...

It creates increased AF(air/fuel) velocity at lower RPM's, thru the carb and intake manifold, enhancing throttle response and TRQ.

Note that none of this is likely to apply to your part throttle surge issue with the airbox/CVk setup you are running..

 

I had a similar stumble with my 300. I raised the needle (lowered the clip) one notch and it went away. Might be worth a try.

 

144/1N is stumble free and rocks....you're just a UNI filter and no lid away....

 

Thanks guys! It's very slight. 100rpm + or - and it's. Gone. Its only in 6th gear. Overall she runs awesome and plug color looks good so not too concerned.