so i did a 107 build in my fxdbi. Had a PCV in the bike(when it was an 88). Tuner figured that wasnt sufficient for the build. So i got talked into doing a dyno tune with his own personal powervision(just pay for another license)on my stock ECM. Well i broke the bike in. He tuned it and the dyno graph had a dip in it from 2500-3500, which i was told was likely from my exhaust(scratch head). Ok, take their word for it. Get the bike home, ride it, the damn thing jerks and sputters from 2500-3500. So take it back, he runs the bike around town with his PV hooked up and it makes some changes, which fixes my problem. NICE!

Well now, got it home again and out cruising, now theres a “dead spot”(best way i can describe it) at about 1/4 throttle from about 3500-redline(likely). Just sputters and spits as long as you hold it there/wont pick up speed. This problem was absolutely not present before we fixed the first issue.

Can anyone give me a couple options on what I should do? I mean i can buy a PV and auto tune myself. But I am not a tuner by any means. Or should I go another route? Like I said I can auto tune but i wouldnt know how to adjust any settings according to thottle position(which is what I am assuming needs to be tweaked). Because if I crack it past that point, itll go. And no problems with throttle position before that spot either.

Bike is an 06 dyna, 6 speed. 107, 3B heads, hpi 58mm intake/TB and 5.3 inj. Supertrapp supermeg exhaust fully open, tman 625 cams

The baffles are in, no plates. The issue will happen in any gear, at 1/4 throttle from about 3509-4500 rpm. Compression at 10.5:1

this issue was not present before I had my tuner fix the initial problem of sputtering/jerking(likely too rich)at 2500-3500. So im thinking the auto tune that he ran fixed one issue but created another.

Pretty sure running the pipe with discs will hurt performance. Thats what I took from what my builder said anyway.

A lot of assumptions are made about exhaust systems and how they “would” affect performance.
9 out of ten times by “fixing” the exhaust resistance makes a much better running bike and not a loss in power. Sound too good to be true? Put 15-18 discs and a 1 1/2 hole in the end cap and come back ant let us know how she runs. Then take it to a dyno and see if you lost power.
Bob

Do ya think that will solve my problem?

Two professional tuners with many years of tuning these bikes stated the same thing very well could be what is causing your drivability issues.
Believe it so you will try it, not question it. ;-)
Bob

Strange...my other exhaust doesnt have discs and it rides real good 😝

I will add to the list of tuners that agrees it could very well be an exhaust issue. Why not try It instead of saying that’s not possibly it??!
if your tuner is only auto tuning, maybe you need to find a different tuner as well.

Same engine build? Cams? Same exhaust model?
Just because one exhaust works well with one build doesn’t mean it will act the same with different engine mods.
FWIW, you may just need to get it to a competent tuner to get it straightened/tuned out.
Bob