Adjusting Ignition Advance

[D0wn5h1ft]

Yes, technically backpressure isn't the 'fix'; but introducing whatever to break up those waves generally introduces backpressure...

Before you spend more money, you might want to try the 'washer fix' as outlined in the link I gave you to see roughly how much of a 'baffle' you need. This why not all mufflers are created equal; lack of noise doesn't always mean lost power any more than more noise always means more power. You may find that a simple baffle such as you linked to won't do the job. That dyno sheet I linked to show a hole in the power curve, but those bikes still ran decent with no stumble, just a very noticeable flat spot. If you have an actual stumble, more drastic measures may be needed... like a muffler of some sort.

I think I'll do that washer trick first, or something similar. I'll have to see what I have lying around. I might machine up something custom and flashy once I get an idea of what it's going to take.

As far as the stumble, it just felt like a rich condition. It was more of a flat spot I had to fight through than anything. The bike wasn't shaking like I've had before when I had a bad stumble.

Just another question to help complete the picture of your issues. What grade of fuel are you running in the bike??

I never run anything below mid-grade (89 octane).

[crazy steve]

Correct me if im wrong but retarding your ignition causes pinging ( detonation ) not advancing it

Nope, backwards; retard to get rid of pinging.